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Egypt is treating the Nile River Water to produce drinking water
and this process generates large amounts of waste
which is called water treatment plant sludge (WTPS)
This WTPS cost the government around 30 million US dollars to return it back to the Nile River in addition to negatively affecting the environment
there is an urgent need to find environmentally friendly alternatives that reduce the impact of such an issue
This paper focuses on treating WTPS by drying
grinding and calcining to develop it as an alternative binder for use in alkali-activated concrete
This approach would not only provide green construction material but also reveal an environmental disposal route for the sludge produced in Egypt or in any country has the same issue
The treatment methodology used in this study was based on finding the optimum calcination temperature regime for WTPS after drying and grinding
Fifteen specimens of WTPS powder were used to investigate the optimum calcination temperature and duration by applying different temperatures ranging from 500 °C to 800 °C for various exposure durations of 30
XRD and Chapelle tests were employed to chemically investigate the efficiency of the obtained calcined WTPS specimens
while strength activity index and compressive strength tests were used to mechanically verify the findings of the chemical tests
The results indicated that the calcination regime
which involved applying a maximum temperature of 650 °C for 90 min
achieved the best chemical characteristics and a strength activity index of 145%
this regime resulted in a compressive strength of 21 MPa when WTPS powder was used as a precursor in alkali-activated concrete
this paper presented a brief comparison of the production cost and energy consumption between cement and WTPS
The comparison demonstrated the efficiency of using WTPS as a replacement for cement
showing that the production of WTPS costs 50% less and consumes 92% less energy than cement
very few studies have evaluated the activation of WTPS through calcination or mixing with an activator solution with the aim of producing green alkali activated material
the activation of WTPS (aluminosilicate source) through grinding and firing is considered an environmentally friendly solution for construction applications because it provides a safe disposable route for WTPS in addition to providing a green binder material
This paper aimed to determine the optimum treatment calcination regime in terms of temperature and exposure duration for WTPS to be used as a precursor in alkali-activated concrete by measuring the pozzolanic reactivity of the treated WTPS powder
the material phase changes that took place at different calcination temperature and duration were assessed
the mechanical characteristics of the treated WTPS
in terms of strength activity index and compressive strength
an economic and energy feasibility study was conducted to verify the adequacy of replacing cement with WTPS in terms of both cost and energy consumption
</a>XRD results of the in-nature WTPS powder (before calcination).
</a>Schematic of the full preparation cycle of the WTPS powder
</a>Heating regime applied to the WTPS specimens
To investigate the efficiency of the obtained calcined WTPS specimens and to determine the optimum calcination methodology
all the calcined WTPS specimens were tested chemically by the Chapelle method
by XRD and XRF tests and mechanically by the strength activity index and compressive strength tests
(b) Titration process using phenolphthalein indicator
The pozzolanic activity of the tested WTPS specimens was calculated using the following
formula<a data-track="click" data-track-action="reference anchor" data-track-label="link" data-test="citation-ref" aria-label="Reference 22" title="Standard, A. S. T. M. C 188–2017, Standard Test Method for Density of Hydraulic Cement ASTM International. (2017)." href="/articles/s41598-025-85225-6#ref-CR22" id="ref-link-section-d499393021e1635">22</a>:
\(PAS\,=\,2 \times \left( {V1 - V2/V1} \right) \times \left( {74/56} \right) \times 1000\)
PAS is the pozzolanic activity of the tested WTPS specimens (mg CaO consumed/g WTPS); V1 is the volume of 0.1 N HCl (ml)
which is necessary for the titration of 25 ml of the filtrated solution obtained without WTPS; V2 is the same but for the solution obtained with WTPS; and 74 and 56 are the molecular weights of Ca(OH)2 and CaO
The recorded average V1 and V2 for the 15 WTPS specimens are substituted in the above equation
and the resulting PAS value is compared to the value of 700
A PAS greater than 700 indicates that a pozzolanic reaction occurred
The highest PAS value recorded resembled the best pozzolanic reactivity
which was the optimum calcination temperature and exposure duration for WTPS
XRD was also conducted to assess the changes in the material phases of the WTPS powder specimens calcined at different temperatures and for different exposure durations
This test was used to verify the results obtained by the Chapelle test
Three specimens were selected based on the obtained PAS values; these three specimens had the highest
An XRF test was used to verify the findings of the Chapelle test chemically
where the chemical composition of the specimen
was examined and compared to both its XRD results and the XRF test obtained for the in-nature specimen
</a>The obtained PAS values for all the calcined WTPS test specimens
</a>Comparison between the in-nature and (650 − 90) WTPS specimens in the XRF results
The recorded results of the strength activity index confirmed the findings of the Chapelle
The treated WTPS is proved to be activated and can work as a precursor in geopolymer material
</a>Shape of the performed cubic specimens. (a) Control mix cubes. (b) Test mix (650 − 90) cubes.
</a>Compressive strength results of the four tested alkali-activated mixes
WTPS production costs almost 50% less than the production cost of cement
It can be concluded that the WTPS provides an economic and energy efficient alternative to cement to be used in the construction era
This study aimed to determine the optimum treatment for water treatment plant sludge (WTPS) by calcination to develop WTPS as a precursor for alkali-activated materials
the paper focused on carrying an economic and energy feasibility analysis for WTPS
Based on the analysis and discussion of the results obtained
WTPS can be developed as a precursor for alkali-activated materials by applying proper calcination treatment
Based on the Chapelle test (PAS value 1194)
XRF test and strength activity index test results (145%)
calcination of the WTPS powder increased its pozzolanic reactivity
aluminosilicate oxides and strength activity
The optimum calcination treatment of the WTPS powder
which achieved the best chemical and mechanical characteristics
was obtained by applying calcination regium at a maximum temperature of 650 °C for a 90 min duration
the calcined WTPS powder can be used to produce alkali-activated concrete with a desirable compressive strength around 21 MPa
WTPS provides an economic and energy-efficient alternative to cement as the production of WTPS requires 92% less energy and costs almost 50% less than the cement production
All data generated or analyzed during this study are included in this published article
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There are no funding sources for this research
All of the tests were carried out at the laboratories of the faculty of engineering
Writing– original draft.I.A.: Conceptualization
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Author’s name Jasmin Osama Abdelhalim Ismail Amer Ibrahim Abdel Latif Ihab Fawzy Sayed Ismail Mohamed A
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The present article investigates the potential of co-calcination with kaolinite as a sector-wide solution for the transformation of bauxite residue into an effective supplementary cementitious material (SCM)
Bauxite residues from eight alumina refineries were co-calcined with 30&#x000a0;wt% of kaolinite at 750&#x000b0;C
SCMs with moderately high reactivities were obtained
Mortars with 30&#x000a0;wt% replacement of Portland cement (CEM I) by co-calcined bauxite residue had relative strengths of 73 &#x000b1; 4%
and 28 days compared to a CEM I reference mortar
The reactivity and contribution to strength development were shown to scale linearly with the kaolinite dosage
Most bauxite residues require only 20&#x000a0;wt% substitution by kaolinite to reach the reactivity and performance targets
Co-calcination reduced the mobility of heavy metals significantly
The negative effect on the workability that some BRs with higher content of free sodium exhibited was mitigated by co-calcination
This positive effect was also observed after calcination with 10 and 20&#x000a0;wt% of kaolinite
The same was found for the positive effect on the leaching of heavy metals
The inherent reactivity of the bauxite residue mainly stemmed from the desilication products such as sodalite and cancrinite
the sodium-containing phases reacted with kaolinite
delivering a supplementary cementitious material with high reactivity and low free-sodium content
Considering that a realistic cement replacement level by BR as an SCM could be 20&#x02013;30&#x000a0;wt%
the entire annual BR production could be absorbed by the cement industry at the European and global levels
This article develops the co-calcination process further to study its potential for transforming BR into a reactive and robust SCM
The potential of co-calcination is evaluated for a range of BRs from a wide variety of alumina plants
The cause of reactivity is identified and the possibility of tuning the technical and environmental quality criteria is explored
explaining why and how bauxite residue can contribute to the formation of hydration products in a cementitious system
Bauxite residues (BRs) from eight alumina plants were investigated. Samples were dried at 105&#x000b0;C until a constant mass was obtained. Afterward, deagglomeration was carried out in a disc mill. The chemical composition of the BRs&#x02013;given in <a href="#T1">Table 1</a> was measured on glass beads (1.4&#x000a0;g of BR with 12.6&#x000a0;g of lithium borate and lithium bromide flux
prepared at 1,050&#x000b0;C) using quantitative X-ray fluorescence (XRF) using matrix-matched standards by means of a Bruker S8 Tiger WDXRF spectrometer
The loss on ignition from an ambient temperature to 1,000&#x000b0;C was determined using thermal analysis
Portland cement from Holcim (CEM I 52.5&#x000a0;N) and kaolinite from VWR (Bole White) were used
&#x0003e; 1&#x000a0;wt%) of the bauxite residues determined by WD-XRF and loss on ignition by thermal analysis
The information of the Holcim CEM I as delivered by the supplier is added (this cement also includes 1.0&#x000a0;wt% MgO
Particle size distributions were determined using a Horiba LA-350 laser diffractometer
The raw BRs were measured thrice to obtain information on the sample inhomogeneity
The samples were dispersed in isopropanol using ultrasound prior to the measurements
The phase composition was studied using X-ray diffraction (XRD) on a PANalytical Empyrean with a Co source
Measurements were carried out at 40&#x000a0;kV and 45&#x000a0;mA
using a step size of 0.0131&#x000b0; 2&#x003b8; and a counting time of 0.02&#x000a0;s/step
An analysis was done using HighScore X&#x02019;Pert software supported by the PDF-4 database
Quantitative results were obtained from Rietveld refinement using an external rutile standard for the quantification of the amorphous fraction
The external standard was measured maximum 10 days before/after the measurements of the samples
The selected structure files and fitted diffractograms are provided in the supplementary information for the reader&#x02019;s review
The BRs and kaolinites were manually blended after drying until no color difference was observed in the blend and afterward shaken and turned around in a closed bottle to further homogenize the powder mixture
the hardened paste samples were embedded in epoxy resin
Backscattered electron images and EDS mappings were taken in a FEI Nova NanoSEM 450
Additional calorimetry measurements to study the kinetics of hydration were carried out on cement pastes composed of 70&#x000a0;wt% of the CEM I and 30&#x000a0;wt% of calcined BR using a water/solid ratio of 0.5
These measurements were carried out for 28 days at 20&#x000b0;C
The performance properties and environmental compatibility of the co-calcined BRs as SCM were investigated by making mortars according to EN 196&#x02013;1 with 30&#x000a0;wt% substitution of the CEM I by the SCMs
35&#x000a0;wt% active content) was added to reach the same mortar flow (measured according to EN 1015&#x02013;3) as a CEM I reference sample
The compressive strength was measured according to EN 196&#x02013;1&#x000a0;at days 2
and 28 (on 4 samples per mixture per day) and batch-leaching tests were carried out on the broken mortars after 28 days according to EN 12457&#x02013;2 simulating the end-of-life scenario and the environmental requirements for the second life of concrete
BR is a fine material. After deagglomeration, the d50 of all received samples was &#x0003c;10&#x000a0;&#x000b5;m (<a href="#T2">Table 2</a>). Most samples have a d50 of about 3&#x000a0;&#x003bc;m, apart from those originating from the Alcoa factories. These values are in line with published observations (<a href="#B28">Ribeiro and Morelli 2011</a>; <a href="#B19">Manfroi et al., 2014</a>; <a href="#B30">Romano et al., 2018</a>)
the variation between BRs is limited across all percentiles
The minor variations observed are similar to batch-to-batch variability and sample inhomogeneity (the latter was experimentally confirmed)
The calcination process does not have a significant or consistent effect on the particle size distribution
there would be no need for milling after the calcination process
Percentiles of the particle size distribution of the BRs before and after calcination
The quantities of the detected phases are given in detail in <a href="#SM1">Supplementary Table S2</a> (supplementary information) for the raw BRs, the calcined BR100s and the co-calcined BR70/Ks are visualized in <a href="#F1">Figure 1</a> for the raw BRs. A rough estimation of the nano-crystalline structures not detected by XRD was made based on mass&#x02013;balance calculations using the XRF data (for Si and Ca) from <a href="#T1">Table 1</a>
This is only carried out for the raw BRs before calcination
The Ca not found in crystalline phases was attributed to nano-crystalline hydrogarnet
the remaining Si not found in crystalline phases or nano-crystalline hydrogarnet was used to calculate the nano-crystalline DSP (desilication products; sodalite or cancrinite)
The nano-crystalline hydroxides were calculated by subtraction from the total XRD amorphous
No distinction is made between Fe-hydroxides or Al-hydroxides
as it is not possible to provide a trustworthy result due to the extensive solubility of Al and other elements in the goethite phase and the associated difficulties in the Al and Fe mass balance
Quantification of the major phases in the raw BRs
&#x0002a;the quantity of DSP and hydrogarnet also takes into account the calculated amount of nano-crystalline DSP and hydrogarnet
During (co-)calcination, the hydroxides transform into oxides. The increase in hematites is clearly observed in <a href="#F2">Figure 2</a>, but aluminum oxides were not detected for most of the calcined BRs. Only in Myt100, corundum was detected (<a href="#SM1">Supplementary Table S2</a> in supplementary information)
the rest of the aluminum oxides probably were XRD amorphous
Titanium-containing phases remained relatively stable during (co-)calcination
Calcite and muscovite/illite were significantly lowered during calcination
but complete decomposition was not achieved
No free limes were detected in the calcined materials
so it is expected that the Ca from calcite was incorporated in the XRD amorphous phases
Complete decomposition of the hydrogarnet phase and the minor content of kaolinite occurred during calcination
a clear crystalline reaction product from the calcined hydrogarnet was identified
as the Myt BR is the one with the highest hydrogarnet content
A garnet phase with similar lattice parameters as the hydrogarnet was observed
but the structure was not completely destroyed
The DSP content stayed relatively stable during calcination (BR100) or even a slight increase could be noticed due to the crystallization of a part of the XRD amorphous DSP
the co-calcination process (BR70/K) significantly lowered the DSP content
some of the Na is bound in nepheline in five of the eight BRs
instead a very low amount of albite could be fitted to the diffractograms
but the quality of the fittings was improved by the addition of a broad albite signal
kalsilites or alunites were detected after calcination
the amorphous content was increased by the calcination process
but an estimation of the nature and quantities of the nano-crystalline phases based on mass balance could not be made
The differences from calcined BR100 to co-calcined BR70/K have to be interpreted in light of the addition of roughly 30&#x000a0;wt% of metakaolinite
The phases that decreased in quantity significantly more than the expected dilution effect were the DSP phases
there might also have been a decrease for the grossular garnet
These decompositions occurred at the benefit of additional XRD amorphous content on top of the 30&#x000a0;wt% of metakaolinite
The combination of metakaolinite and DSP at a high temperature led to an interaction decomposing the crystalline DSP and forming an XRD amorphous phase
The results are averaged over the eight different origins of the BRs
Only the crystalline part of the DSP and hydrogarnet is taken into account
Boxplots giving the cumulative heat at 7 days in the R&#x000b3; test of BR before and after (co-)calcination
Having a reactivity higher than fly ashes might not be needed for many cement and concrete applications. The co-calcination with varying kaolinite contents is therefore investigated in more detail for a random selection of three BRs. The cumulative heat depicted in <a href="#F4">Figure 4</a> shows an approximately linear relationship with the kaolinite content in the feed for calcination for the three studied BRs
simply be chosen and controlled by the wt% kaolinite addition to the bauxite residue before calcination
Variation with a kaolinite replacement of BR before calcination of the cumulative heat at 7 days in the R&#x000b3; test
A small but significant contribution to the reactivity is made; however
the increase in reactivity is lower than that of the corresponding share of calcined BR100 sample
Comparison between co-calcined BR and reference mixtures
and alumina phases did not react significantly
The phases that are new or increased in content are the products of reaction of the SCM with the R3 mixture-containing portlandite
These reaction products are monocarboaluminate
The quantification of the amorphous phases included the quantity of C-S-H
Quantification of the major phases in the calcined Mytilineos BR and the reacted R3-like paste made from it
The XRD amorphous nano-crystalline DSP should have a similar (or slightly higher) reactivity as its crystalline equivalent. Confirmation of the low reactivity of the dehydroxylated Al-hydroxides was obtained from microchemical investigations. The SEM image and elemental EDS maps of the hydrated R&#x000b3;-like paste in <a href="#F7">Figure 7</a> shows particles which are pure Al (oxygen was not included in the figure
Most images taken using SEM contained such alumina particles
The nano-crystalline alumina does not react extensively
SEM image and elemental maps of the reacted R&#x000b3;-like paste
the BR itself did not contribute as extensively to the increased superplasticizer requirement as for the BR100 samples
and about half of the workability loss can be attributed to the metakaolin
The limited increase in superplasticizer requirement of the BR70/K-containing samples in comparison with the samples with co-calcined quartz filler is likely related to a combined effect of the fineness of the BR (dominant) and a minor amount of residual soluble sodium (subordinate)
Superplasticizer requirement of the mortars including (co-)calcined BR as SCM
The dashed line indicates the superplasticizer requirement of quartz co-calcined with 30&#x000a0;wt% of kaolinite
The avoidance of severe acceleration from 10&#x000a0;wt% of kaolinite shows that already a minor amount of kaolinite added before calcination results in an interaction during calcination enabling it to bind most of the free sodium in the BR
Heat flow from pastes with 70&#x000a0;wt% of CEM I and 30&#x000a0;wt% of (co-)calcined BR
The reference sample (Ref) shows the heat flow of a paste with 70&#x000a0;wt% of CEM I and 30&#x000a0;wt% of quartz filler
which might have caused a low workability of the mortar and increased porosity or molding defects of the mortar test samples
Compressive strength of mortars with 30&#x000a0;wt% of (co-)calcined BR as SCM relative to a reference sample of the CEM I
The dashed lines indicate the relative strengths of a mortar with co-calcined quartz Q70/K as a basis of comparison for the BR70/K samples
When the BR was co-calcined with 30&#x000a0;wt% of kaolinite
Concentration of Cr in the leachate after batch-leaching in mg/kg dry matter
The leaching of the mortars after 28 days is compared with the EU inert waste leaching limit (IWLL)
The variation with kaolinite addition to BR before calcination of the compressive strength and chromium leaching of mortars after 28 days
In an attempt to match the availability of bauxite residues and the need for high-volume SCMs
a co-calcination process was proposed and investigated in this article
The performance of co-calcined bauxite residue and kaolinite at 750&#x000b0;C for use as SCM was assessed using bauxite residues from eight alumina refineries
SCMs with a moderate/high reactivity were obtained when co-calcining 30&#x000a0;wt% of kaolinite with 70&#x000a0;wt% of the bauxite residue
The reactivity can be adapted using the wt% of kaolinite in the blend
The inherent reactivity of the bauxite residue mostly originated from desilication products such as sodalite and cancrinite
as observed from the phase composition of an R3-like paste after curing
the sodium-containing phases reacted with the kaolinite/metakaolinite phase
decreasing the soluble sodium in the calcined product
The contribution to strength development of mortars incorporating 30&#x000a0;wt% of SCM was related to the kaolinite content in a similar way as the reactivity
The reactivity and strength development did not vary substantially with varying bauxite residue sources
The presence of soluble sodium in the bauxite residue additionally increased the early strength of the mortar
but negatively affected the later age strength
The workability of the mortars was slightly decreased by the addition of (co-)calcined bauxite residue
although excessive acceleration of the hydration reactions and fast setting could be avoided by use of 10&#x000a0;wt% of kaolinite in the co-calcination blend (or more)
The co-calcination with kaolinite also decreased the leaching of Cr from the mortars and lowered the values below the EU inert waste leaching limit already at 10&#x000a0;wt% of co-calcined kaolinite
The original contributions presented in the study are included in the article/<a href="#SM1">Supplementary Material</a>; further inquiries can be directed to the corresponding author
The research leading to these results has been performed within the REACTIV project and received funding from the European Community&#x02019;s Horizon 2020 Programme (H2020/2014-2020) under grant agreement no
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations
Any product that may be evaluated in this article
or claim that may be made by its manufacturer
is not guaranteed or endorsed by the publisher
The authors are thankful to the alumina plants and Holcim for providing the materials that made this study possible
Special thanks go out to the VITO lab technicians for carrying out the experiments
The Supplementary Material for this article can be found online at: <a href="https://www.frontiersin.org/articles/10.3389/fmats.2022.913151/full#supplementary-material">https://www.frontiersin.org/articles/10.3389/fmats.2022.913151/full&#x00023;supplementary-material</a>
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Hertel T and Snellings R (2022) Co-Calcination of Bauxite Residue With Kaolinite in Pursuit of a Robust and High-Quality Supplementary Cementitious Material
Received: 05 April 2022; Accepted: 23 May 2022;Published: 06 July 2022
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Germany: Aumund and Holcim have demonstrated an electric linear calcination conveyor (eLCC) at Aumund’s headquarters in Rheinberg
Initial tests of the eLCC have reportedly demonstrated efficient thermal activation of clay through a combination of radiant heat and material circulation
Aumund Fördertechnik teamed up with Holcim for a project focused on the electrical calcination of clay using an Aumund pan conveyor
The company stated that the eLCC system is fully enclosed and insulated
minimising energy requirements and heat loss
with its compact design allowing for expansion of production capacities
It can operate with electrical heating elements powered by 100% renewable energy sources like wind or solar
The first industrial plant utilising this technology will be constructed in 2025
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The paper deals with the economic optimisation of ferrite powder preparation during producing hard ferrite magnets
The magnetic properties of ferrites are investigated by replacing feedstock and reducing calcination temperature and particles in the order of tens of microns
The granulates about 8–10 mm in size were calcined for 2 h in the temperature range from 1100 °C to 1300 °C and additionally crushed and milled to an average particle size of about 80–90 µm
The scanning electron microscopy images confirmed the agglomerates of particles with different shapes and sizes in tens of µm
The X-ray diffraction measurements revealed that
besides the SrFe12O19 and BaFe12O19 phases
there was also the presence of 2–39% hematite
The highest values of maximum energy product (BH)max = 930 J/m3 and remanent magnetic induction Br = 72.8 mT were obtained at a calcination temperature of 1300 °C
The Henkel plots confirmed the presence of exchange-coupling and dipolar magnetic interactions at lower and higher magnetic fields
The strength of interactions was also dependent on the calcination temperature
Replacing strontium with barium led to a deterioration of the magnetic parameters
which were optimal at a lower calcination temperature (1100 °C)
This phenomenon was partly overcome by reducing the mean particle size of Ba-based hexaferrites to 45–50 µm
the effect of calcination temperature and particle size distribution of ground calcite on the magnetic properties of M-type ferrite powders was investigated
The quality of input raw materials mainly influences the calcination process
the temperature profile of the calcination furnace
the furnace flow rate and the processes taking place in the cooling retort of the furnace
The whole research was carried out in cooperation and according to the requirements of the manufacturer of hard ferrite magnets
The study shows the development and optimization of the technology of mixing basic raw materials and grinding of ferrite calcite
determination of the influence of granulometric and frictional parameters of feedstock and setting of preparation technology of ferrite dust as a feedstock for the production of hard ferrite magnets
The aim was to ensure constant and quantifiable outputs from the different parts of the process line
which would improve the final product’s magnetic properties
The findings obtained in a partial study of the effect of calcination temperature and particle size distribution on the magnetic properties of SrFe12O19 and BaFe12O19 ferrite powders are presented
Many publications have focused on improving ferrites’ magnetic
chemical and mechanical properties by increasing calcination temperatures or using finer particles down to the nanometer range
This entails a significant increase in the technological and economic requirements of the process
The main contribution of this study should be to provide an overview of an economically suitable setup usable for routine and sustainable mass production as well as small-scale production
There are a multitude of synthesis methods and technological setups
each study is unique and has its significance
publications are still being published on this topic
Freeman FT4 Powder Rheometer was used to determine the flow properties and compressibility
The flow properties are significant due to the homogenization of both compounds and the compression process used to produce hard ferrite magnets
The particle size distribution was determined by laser diffraction using a CILAS 1190 Particle Size Analyzer (wet method)
The iron oxide is a deep red powder with a mean grain size of 16.5 μm and spherical particle shape with sharp-edged chipped fragments
The flow function is defined as the ratio of the principal normal stress to the interstitial strength of the powder
Iron oxide can be classified as a cohesive powder according to its flow function
Since cohesive properties are often associated with average compressibility
Fe2O3 showed moderate compressibility during testing
Strontium carbonate and barium carbonate are white powders with a rod-shaped grain size of approximately 5.5 μm in the middle
These small particles make the SrCO3 and BaCO3 samples very cohesive (ffc &lt; 2) and form agglomerates
SrCO3 exhibits the highest internal friction angles
cohesiveness and ultimate strength and the worst flow characteristics of all tested samples
The very fine particles also cause a high compressibility of 37.2% at a normal stress of 15 kPa
</a>SEM micrographs of input powders: (a) Fe2O3; (b) SrCO3; (c) Sr_MIX (Fe2O3:SrCO3)
</a>Ferrite powder samples preparation: (a) homogenization; (b) granulation; (c) granulate structure; (d) granules
The X-ray diffraction (XRD) measurements were performed on a Bruker-AXS D8 Advance (Germany) in 2Θ/Θ geometry with a position-sensitive LynxEye detector under the following conditions: CuKα/Ni filter radiation
step mode with 0.014° 2Θ step with a total time per step of 2 s (summation of five measurements with 0.25 s step) and digital processing of the resulting data
The Bruker Diffrac Suite software was used for measurements and data evaluation
The quantification was based on the Rietveld method of structural analysis from powder diffraction data
It consisted of modelling the diffraction spectra using known structural data (lattice parameters
Input structural data were taken from the Bruker DiffracPlus Topas structure database (hematite)
from the COD database (Crystallographic Open Database—SrFe12O19)
and the American Mineralogist crystal structure database (BaFe12O19)
An FEI Quanta-650 FEG auto-emission electron microscope from FEI (Thermo Fisher Scientific) was used for photographic documentation and identifying individual minerals
The imaging was performed using a back-scattered electron detector (BSED) in chemical gradient mode at 10 kV voltage and 4.5–5 µm beam diameter
Anton Paar Ultrapyc 5000 gas pycnometer was used for powder density determination
Magnetic measurements using a MicroSense EZ9 vibrating sample magnetometer (VSM) were performed to confirm and characterise the ferromagnetic state in the studied samples
The measured magnetization curves at room temperature show the dependence of the magnetic polarization J of the sample on the external magnetic field H (J–H curves)
The maximal applied magnetic field was ± 1600 kA/m (± 2 T)
We also plotted B–H curves representing the dependence of the magnetic induction B on the external magnetic field H
The following magnetic parameters were obtained from the J–H and B–H curves: the maximum energy product
The interparticle magnetic interactions of prepared powders were analysed using the Henkel plot (ΔM function)
It describes the relationship between the virgin Mvir (H) and the magnetization curve M(H) using the relation:
where Mup(H) and Mdown(H) are magnetizations in increasing and decreasing positive magnetic field H
Demagnetization of the samples takes place in an alternating magnetic field with an exponential amplitude decrease coefficient of 0.95
</a>SEM micrographs of selected SrFe12O19 and BaFe12O19 hexaferrites: (a) Sr_1; (b) Sr_4.1; (c) Sr_7.1; (d) Ba_1.2; (e) Ba_5.1; (f) Ba_5.2
</a>XRD diffractograms of selected hexaferrite samples: (a) Sr_1; (b) Sr_6.1; (c) Sr_7.1; (d) Ba_5.1
</a>J–H and B–H curves of the Sr_4.1 sample: (a) complete J–H curve measured at high magnetic fields (± 1600 kA/m) including the virgin curve; (b) J–H and B–H demagnetization curves (the second quadrant).
</a>Henkel plots of prepared samples in dependence on the calcination temperature: (a) Strontium ferrite powders with the average particle size d = 80–90 µm; (b–c) Barium ferrite powders with d = 80–90 µm and 45–50 µm
where the powders of average particle size of 35 µm were prepared by ceramic method
Similar shapes of the Henkel plots depending on the calcination temperature show Sr-based samples (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/articles/s41598-024-67994-8#Fig6">6</a>a) and Ba-based samples with an average particle size of 45–50 µm (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/articles/s41598-024-67994-8#Fig6">6</a>c)
These results agree with hysteresis loop measurements
Optimal samples Sr_7.1 and Ba_5.1 calcined at 1300 °C have the strongest positive interactions shifted towards higher H and the negative interactions towards lower H
The strength of the interactions is variable and depends not only on the calcination temperature but also on the particle size
The conclusions of the applied research show that even with economically optimized production
it is possible to achieve satisfactory magnetic properties of ferrite powder for producing hard ferrite magnets
by doping additive elements into the ferrite powder
The main conclusions of the influence of calcination temperature and particle size distribution on the physical properties of hexaferrite powders study are as follows:
The SrFe12O19 and BaFe12O19 hexaferrites were successfully prepared by mixing and granulation from Fe2O3 and SrCO3 (BaCO3)
Additional calcination for 2 h in the temperature range 1100–1300 °C and final crushing and milling to an average particle size of about 80–90 µm was used
Observations during sample preparation and from the SEM images showed that replacing strontium carbonate with barium carbonate is more advantageous
Better flow properties of BaCO3 and the ease of achieving a higher degree of homogeneity with the desired concentration throughout the volume were observed
The morphology of prepared hexaferrites revealed agglomerates consisting of large and small hexagonal-like platelet particles and semi-circular polyhedral particles
The XRD results detected the presence of two phases: dominant SrFe12O19 / BaFe12O19 and minor Fe2O3
The amount of hematite in Ba-based samples was only around 2 wt% and in Sr-based ferrites between 7 and 12 wt%
The highest amount of hematite (about 39 wt%) was observed in the reference sample
The magnetic properties of prepared SrFe12O19 powders with a mean particle size of about 80–90 µm are comparable to the reference sample Sr_1
The sample calcined at 1300 °C achieved better magnetic parameters from the B-H curve
the highest value of Hcj parameter is obtained for the reference sample
and the magnitude of Hcj rather decreases with increasing calcination temperature
All laboratory-prepared samples have higher saturation magnetization than the reference sample due to a markedly lower amount of hematite
replacing strontium with barium led to the marked deterioration of the magnetic properties of prepared powders
A sample calcined at 1100 °C appeared to be optimal
A partial improvement in the magnetic properties of the Ba-based powders was achieved by reducing the mean particle size to 45–50 µm
The samples calcined above 1200 °C have magnetic parameters comparable to those of the reference sample
The Henkel plots revealed a predominance of exchange-coupling (positive) and dipolar (negative) magnetic interactions at lower and higher applied magnetic fields
The strength of both types of interactions is variable
and as the calcination temperature increases
the positive and negative interactions shift to higher and lower magnetic fields
The data used in this study is available at: <a href="https://doi.org/">https://doi.org/</a><a href="https://doi.org/10.5281/zenodo.10890728">https://doi.org/10.5281/zenodo.10890728</a> and <a href="https://doi.org/">https://doi.org/</a><a href="https://doi.org/10.5281/zenodo.10890791">https://doi.org/10.5281/zenodo.10890791</a>
Effect of aluminum substitution on microwave absorption properties of barium hexaferrite
Hexaferrite contribution to microwave absorbers characteristics
Hexaferrites and phase relations in the iron-rich part of the system Sr–La–Co–Fe–O
Temperature dependence of Ms and K1 of BaFe12O19 and SrFe12O19 single crystals
Influence of SiO2 and CaO additions on the microstructure and magnetic properties of sintered Sr-hexaferrite
Magnetic properties of c-axis oriented Sr0.8La0.2Fe11.8Co0.2O1.9 ferrite film prepared by chemical solution deposition
The effect of underlayer for Ba-ferrite sputtered films on-axis orientation
Thick barium hexaferrite (Ba-M) films prepared by electron-beam evaporation for microwave application
Growth and characterization of thick oriented barium hexaferrite films on MgO (111) substrates
Study of the sintering temperature and the sintering time period effects on the structural and magnetic properties of M-type hexaferrite BaFe12O19
Structural and magnetic properties of barium hexaferrite nanostructured particles prepared by the combustion method
Inter-grain effects on the magnetism of M-type strontium ferrite
Magneto-dielectric properties of doped ferrite based nanosized ceramics over very high frequency range
Structure and multiferroic properties of barium hexaferrite ceramics
Attractive microwave-absorbing properties of M-BaFe12O19 ferrite
magnetic and low-frequency microwave absorption properties of doped Co–Ti hexagonal barium ferrite nanoparticles
Study of structural and selected mechanical/physical properties of metal powders
Proceedings of the METAL 2015: 24th International Conference on Metallurgy and Materials
Mechanical properties of powdered coal and their influence to technological processes
structural and photocatalytic properties of mixed Mn-Zn ferrites nanoparticles embedded in SiO2 matrix
Influence of Mn2+ substitution with Co2+ on structural
morphological and coloristic properties of MnFe2O4/SiO2 nanocomposites
morphology and magnetic properties of Ni0.6Mn0.4Fe2O4 nanoparticles embedded in SiO2 matrix
morphological and photocatalytic properties of Ni-Mn ferrites: Influence of the Ni:Mn ratio
Thermal annealing effect on the structural and magnetic properties of barium hexaferrite powders
The effect of post annealing treatment on the citrate sol–gel derived nanocrystalline BaFe12O19 powder: Structural
stability range and high frequency permeability of some ferroxplana compounds
Angew Ferrite hexagonaler Kristallstrustur mit hoher Grenzfre-quenz
Phase relationships in the BaO-CoO-Fe2O3 system
Topotactic reaction kinetics in the formation of the hexagonal ferrite Ba3Co2Fe24O41
Electron microscopic studies of growth structures in hexagonal ferrites
Magnetic parameters of SrFe12O19 sintered from a mixture of nanocrystalline and micron-sized powders
Investigation of BaFe12O19 hexaferrites manufactured by various synthesis methods using a developed pulsed magnetometer
Impact of annealing temperature and ferrite content embedded in SiO2 matrix on the structure
morphology and magnetic characteristics of (Co0.4Mn0.6Fe2O4)δ (SiO2)100-δ nanocomposites
Study on the obtaining of cobalt oxides by thermal decomposition of some complex combinations
Low temperature synthesis of Co2SiO4/SiO2 nanocomposite using a modified sol–gel method
Sol−gel based chemical synthesis of Nd2Fe14B hard magnetic nanoparticles
Structural and magnetic properties of nanocomposite Nd–Fe–B prepared by rapid thermal processing
Effect of surfactant-assisted low-temperature annealing on the refinement of particle size and enhancement of magnetic properties of SrFe12O19 ferrite
Enhanced calcination temperatures of SrFe12O19 synthesized by local iron sand from Lombok Island
Reactive flash sintering of SrFe12O19 ceramic permanent magnets
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Faculty of Electrical Engineering and Computer Science
This paper was created as part of the project No
CZ.02.01.01/00/22_008/0004631 Materials and technologies for sustainable development within the Jan Amos Komensky Operational Program financed by the European Union and from the state budget of the Czech Republic
All authors have read and agreed to the published version of the manuscript
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Nanohydroxyapatite (nanoHAP) is widely used in bone regeneration
but there is a need to enhance its properties to provide stimuli for cell commitment and osteoconduction
This study examines the effect of calcination at 1200 °C on the physicochemical and biological properties of nanoHAP doped with magnesium (Mg2+)
A synergistic effect of dual modification on nanoHAP biological properties was investigated
The materials were characterized by X-ray diffraction (XRD)
ion release tests and in vitro biological characterization
osteoconductive potential and cell proliferation
The XRD results indicate that the ion substitution of nanoHAP has no effect on the apatite structure
β-tricalcium phosphate (β-TCP) is formed as an additional phase
SEM analysis showed that calcination induces the agglomeration of particles and changes in surface morphology
A decrease in the specific surface area and in the ion release rate was observed
Combining calcination and nanoHAP ion modification is beneficial for cell proliferation and osteoblast response and provide additional stimuli for cell commitment in bone regeneration
HAP modified by incorporating ions holds significant promise in addressing bone-related concerns
by supporting bone regeneration and enhancing bone strength
or zinc (Zn2+) incorporation enhances HAP's bioactivity and its potential for bone healing
the medical application of ion-modified HAP requires further research to understand their impact on physicochemical and biological aspects and their intricate interplay
the success of bone regeneration is contingent upon various influencing factors
achieving favorable outcomes in bone regeneration necessitates a comprehensive approach that accounts for the synergy of these factors
This study aims to determine the effect of calcination at 1200 °C and ion modification on the physicochemical and biological properties of nanohydroxyapatite
and osteoconduction of nanoHAP doped with magnesium (Mg2+)
The innovative nature of this study lies in assessing the impact of dual modifications of nanoHAP as a candidate for material with biomedical applications
A simple method of producing modified nanoHAPs by ion doping based on precipitation from aqueous solutions
combined with innovative thermal processing
These novel synergistic dual modifications enhance the materials' potential to prompt cellular commitment
and the results were compared with pure HAP
A part of the nanoHAP powder was calcined at a temperature of 1200 °C for 1 h (conditions: heating at 10 °C/min to 1200 °C
cooling at 10 °C/min to 20 °C and then air-cooling to room temperature)
to ensure that possible traces of ammonium nitrate were eliminated from the synthesized nanoHAP materials
The properties of materials after the calcination process were compared with non-calcinated nanoparticles
The phase composition of the synthesized powders was analyzed using the X-ray diffraction technique
The analyses were performed on a Bruker-AXS D8 DAVINCI diffractometer with a copper anode lamp in the Bragg–Brentano geometry
Diffractograms were recorded in the 2θ angular range from 5° to 120° (Cu Kα) at a measurement step of 0.01° and a measurement time 2 s/step
The crystalline phases were identified by comparing the registered diffractograms with the patterns in Crystallography Open Database (COD) using the DIFFRACplus EVA-SEARCH software
crystallite size and phase concentrations were calculated using the Rietveld method in Topas v5.0 software
To calculate crystallite size the LVol-IB was used which applies FWHM and integral breadth to give volume-weighted mean crystallite sizes
Scanning electron microscopy with field emission was used to define the microstructure (shape and grain size) of the obtained hydroxyapatites (Nova NanoSEM 200
The samples were covered with a conductive material (20 nm gold film) using a sputter coater (EM SCD500
The hydroxyapatite imaging was performed in high vacuum conditions using a secondary electron detector at 10 kV accelerating voltage and at a magnification of 100,000×
Energy dispersive spectroscopy analysis was carried out to confirm the ion substitution on the uncoated samples (Octane Elect EDS
EDS analysis was performed in low vacuum conditions at 15 kV accelerating voltage
The Brunauer–Emmett–Teller (BET) method was used to assess a specific surface area of the samples with Gemini VII 2390t Micromeritics analyzer
The analysis was based on the determination of 9 points of nitrogen adsorption isotherm in the pressure range of 0.05–0.25 p/p°
where p and p° are the equilibrium and the saturation pressure of adsorbates at the liquid nitrogen temperature
the samples were degassed at 105 °C in the N2 atmosphere for 1 h to dry and purify the samples
The infrared spectra were recorded on Bruker TENSOR 27 instrument equipped with a DLaTGS detector
Powder samples were analyzed in the transmission mode with the following instrumental settings: wavenumber range of 400–4000/cm
Each sample was measured twice to check repeatability
The baseline correction procedure has been applied to the presented spectra with Opus 7.2 software
The thermal properties of the powdered materials were analyzed with a STA F3 449 Jupiter® Netzsch thermal analyzer
TG–DTA experiments were performed under a dynamic flow of argon (70 mL/min) to investigate the particular mass loss due to the presence of a modifier
The 10 − 12 mg samples were heated from 30 °C up to 1400 °C at a heating rate of 10 °C/min in an Al2O3 DTA pan with a lid and a hole
The measurements were repeated twice for each sample
The ion release was investigated by immersion of 1 g of each sample in 10 mL ultrapure water and further incubation
The incubation procedure was performed at 37 °C in a separated closed flask for each sample
the collected supernatant was filtered through 0.45 µm paper filter
Determination of selected elements was performed with inductively coupled plasma optical emission spectrometry (ICP—OES) using a Shimadzu ICPE 9800 spectrometer
The calibration solutions were prepared from Merck ICP multielement standard XVI storage solution (for Ca
The quantification limits of the method for the cations were 0.08 mg/L for Ca
The conducted analytical tests meet the ISO 11885:2009 requirements
Intergroup outcomes were compared between non-calcinated and calcinated samples for statistical significance using two-way ANOVA (analysis of variance) and Tukey's test
all nanohydroxyapatite powders were sterilized by gamma radiation (35 kGy
60Co source) at the Institute of Applied Radiation Chemistry at the Lodz University of Technology (Lodz
The L929 (CCL-1) mouse skin fibroblasts recommended by the International Standard Organization (ISO) for the biological evaluation of biomaterials for medical applications were obtained from the American Type Culture Collection (ATCC
Fibroblasts were cultured in Roswell Park Memorial Institute (RPMI)-1640 medium supplemented with 10% heat-inactivated fetal bovine serum (FBS; HyCloneCytiva
and streptomycin (100 μg/mL) (Sigma-Aldrich
in a humidified 5% CO2 atmosphere at 37 °C in cell culture incubator (Nuaire
The human fetal osteoblastic cell line hFOB 1.19 (CRL-11372™) was obtained from the American Type Culture Collection (ATCC
The cells were cultured in Dulbecco's Modified Eagle's Medium/Ham's Nutrient Mixture F12 without phenol red (1:1 DMEM/F12 Modified; Gibco; Thermo Fisher Scientific
USA) containing a 0.3 mg/mL geneticin (Sigma-Aldrich
USA) and supplemented with a 10% fetal bovine serum
The cell cultures were incubated at 34 °C in the incubator with a humidified air atmosphere containing 5% CO2
The confluent (80–90%) cell monolayers were periodically subcultured using a 0.5% trypsin-0.5 mM ethylenediaminetetraacetic acid tetrasodium salt (EDTA) solution (Gibco
The cell viability was established using a trypan blue exclusion assay
the suspension was used for cell morphology and cell viability assessment
after the overnight incubation of the cells with the tested nanoHAP materials
20 μL of MTT reagent (Sigma Aldrich) at a concentration of 5 mg/mL was introduced into each well and incubated for 4 h (5% CO2
and the supernatants were removed and replaced with 200 μL DMSO per well
After one minute of incubation at room temperature with shaking
the absorbance was measured at 570 nm using the Multiskan EX reader (Thermo Scientific)
Fluorescence was measured at the excitation wavelength of 495 nm and an emission wavelength of 525 nm using a SpectraMax® i3x Multi-Mode Microplate Reader (Molecular Devices
The statistical analysis was performed using GraphPad Prism 6 software (GraphPad Software
Intergroup outcomes were compared for statistical significance using one-way or two-way ANOVA (analysis of variance)
The differences were considered significant at the p-value &lt; 0.05
The experiments were carried out in at least triplicate
</a>X-ray diffraction (a) and scanning electron microscope micrographs and EDS analysis (b) for the pure and ion-substituted hydroxyapatite samples before and after calcination at 1200 °C
</a>Infrared spectra of materials (a) before calcination
The Mg, Sr, and Zn nitrate precursors partially replaced calcium ions in the apatite structure. In the spectra of modified hydroxyapatite before calcination, additional peaks were observed at 1385/cm and 839/cm, which is related to the presence of unreacted nitrates (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/articles/s41598-023-42271-2#Fig2">2</a>a)
the signals of phosphates are partially masked and can be distinguished only after thermal treatment and nitrate degradation (temperature above 500 °C)
a weak band at 838/cm may be related to MgO presence
Other characteristic bands for MgO were not observed or overlapped with similar bands
To follow the structural changes during calcination, FTIR spectra of the material after thermal treatment were compared and are presented in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/articles/s41598-023-42271-2#Fig2">2</a>b
After calcination at 1200 °C some specific bands disappear
those most prominent for nitrates at 1385/839/cm
as thermal degradation of stable ions occurs at temperatures above 500 °C
the band at 1033/cm and the weak band around 1382/cm are shifted
These effects are probably related to the differences between nanoHAP materials regarding hydroxyl and phosphate bands which may suggest a different substitution of HAP sites as well as the formation of different apatites
Calcination leads to the condensation of surface hydroxyl groups with the formation of water
which was proved by the presence of bands at 3734/cm followed by the ones above 3400/cm
</a>Thermal analysis curves for nanoHAP and modified nanoHAP before (a) and after calcination (b)
</a>Release profiles of calcium ions from calcinated and non-calcinated samples of nanoHAP (a) and nanoHAP Zn 0.1 (b)
and strontium ions from nanoHAP Sr 0.1 (d); for calcinated and non-calcinated samples
The release was measured by inductively-coupled plasma—optical emission spectroscopy
Data are presented as mean values and standard deviation of assay triplicates
*p &lt; 0.001 between non-calcinated and calcinated samples based on the two-way ANOVA (Tukey’s) evaluation results
The results demonstrated that if the nanoHAP was doped with zinc ions, the level of calcium release increased almost six times (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/articles/s41598-023-42271-2#Fig4">4</a>a
an interesting fact of a significant increase of calcium release after 42 days of incubation was observed
The calcination process led to a meaningful decrease in the calcium release level
probably due to the stabilization of ions in the hydroxyapatite structure and reduction of the surface area of the tested powders
Non-calcinated nanoHAP Mg 0.1 showed a burst release of Mg2+ ions from the 1st until the 7th day of incubation, ranging from 4000 to 8000 ppm. After 7 days, the release of Mg2+ was decreased to 4200 ppm. Long-term magnesium release was maintained at a similar level until the end of the experiment (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/articles/s41598-023-42271-2#Fig4">4</a>c)
also leads to a significant decrease in magnesium release
For HAP modified with Sr2+ (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/articles/s41598-023-42271-2#Fig4">4</a>d)
significantly lower values of ion release were observed
and this level increases slightly until 21 days of incubation
while after this time decreases to the starting level
Analysis of the calcinated HAP substituted with Sr2+ showed that ion release raised until 42nd day of incubation
and the highest value jump was registered after 21 days of incubation
</a>The MTT reduction assay was used to assess the viability of fibroblasts (a) and osteoblasts (b) after 24 h of incubation with non-calcinated or calcinated (1200 °C) nanoHAP
Data are presented as mean viability calculated compared to control (cells in medium) and standard deviation of assay triplicates
hFOB 1.19: K1: 100.0% ± 7.3%; K2: 4.1% ± 0.1%
K1—viability control (cells in culture medium without the test sample)
</a>Generation of reactive oxygen species (ROS) in hFOB 1.19 cells after exposure to non-calcinated and calcinated (1200 °C) nanoHAP and nanoHAP modified with Zn
and Mg after 1 h (a) or 24 h (b) incubation measured using an H2DCFDA probe
*p &lt; 0.001 between non-calcinated and calcinated samples vs
based on the two-way ANOVA (Tukey’s) evaluation results
l) in hFOB1.19 cell cultures exposed to non-calcinated or calcinated nanoHAP or modified with Zn
The results represent the mean values ± SEM
*p &lt; 0.05 between the calcinated and non-calcinated samples
based on the one-way ANOVA (Kruskal–Wallis test) evaluation results
</a>Proliferation of hFOB 1.19 osteoblasts after 7
and 28 days of incubation with the non-calcinated and calcinated (at 1200 °C) nanoHAP and nanoHAP modified with Zn
The results are expressed as mean relative DNA content (RDC) ± SD calculated from three independent experiments
*p &lt; 0.05 between non-calcinated and calcinated samples
nanohydroxyapatite is widely used in bone regeneration and it is crucial to investigate its possible further improvements
this study aimed to understand the influence of ion doping and calcination on HAP properties and biological activity
The paper presents characterization of nanohydroxyapatite synthesized by precipitation from an aqueous solution
the effect of calcination at 1200 °C was correlated with the influence of the ion modification
The XRD analysis showed that incorporating Sr2+
and Zn2+ into nanoHAP resulted in a structural modification of the HAP lattice due to differences in the size of individual ions
The comparison of unit cell parameters of HAP and β-TCP in the non-substituted and substituted powders suggest that after the calcination process
the Sr ions were included in both HAP and β-TCP crystal structure
while Mg and Zn ions were mainly in the β-TCP phase
No noteworthy observation comes from the thermal analysis of the materials
what may suggest that undetectable amounts of modifiers are present in the structure of nanopowders
The nano-sized material is tough to analyze in TG–DTA experiments
where the dynamic gas flow can cause the nanoparticles’ entrainment by the carrier gas
the bulk material inside the crucible can create an air cushion and interfere with the data recording
The only visible effect is that some hydroxy groups escape from the structure after calcination (mostly loosely bound water molecules)
The results of the ion release test for the nanopowders showed that both ion modification and thermal treatment strongly affected the nanopowders' behavior
pure nanoHAPs changed their original performance
and ion release dropped significantly in all variants
This might have depended on several factors
a significant reduction in the specific surface area of nanoHAP grains after calcination may have mattered
The calcination-induced decrease in the size of the material's specific surface area capable of ion exchange seemed critical in reducing the ions’ release
calcination did not result in the loss of bioactivity and osteoconduction
making these materials attractive for bone regeneration
calcined nanoHAP modified with magnesium and strontium exhibits such potential
this paper presents a detailed study on the fabrication and characterization of nanohydroxyapatite for biomedical applications
A simple method of producing nanoHAPs based on precipitation from aqueous solutions and involving dual modification
has resulted in bioceramics with the desired physicochemical and biological properties
Combining ion modification and calcination at 1200 °C demonstrates notable benefits for enhancing both the structural and biological attributes of the nanohydroxyapatite
These processes exert a significant influence on nanopowder characteristics
Calcination indicates strong distortions of the nanoHAP lattice and reduces crystallinity
which leeds to particle aggregation and modifications in surface morphology
finely textured morphology within the nanoHAP
hold considerable promise for promoting cell commitment and osteoconduction
the formation of new phases in the bioceramic structure
significantly impacts ion release levels and biological activity (osteoblast proliferation and differentiation) of the material
Altered crystallite size influences specific surface area and correlates with ion release
It suggests that both ion modification and thermal treatment strongly affects the nanopowders' properties
The data presented in this study contribute to developing advanced biomaterials for application in bone regeneration and replacement
The results show that substitution of elements
make nanoHAP a multifunctional material ready for further applications or investigations as a component of more advanced biomaterials
calcination may additionally ameliorate the final properties of bioceramics
The synergistic effect achieved through the combination of calcination and ionic modifications presents new opportunities for designing customizable biomaterials with tailored properties
offering novel prospects for various biological and medical applications
The data generated during this study are available at ŁUKASIEWICZ Research Network Institute of Ceramics and Building Materials
Biological research data are available at University of Lodz
Faculty of Biology and Environmental Protection
Department of Immunology and Infectious Biology
All data are available from the corresponding author upon request
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This work was supported by the TEAM—NET programme of the Foundation for Polish Science financed by the European Union under the European Regional Development Fund („The Multifunctional composites biologically active for applications in regenerative medicine of bone system” project [POIR.04.04.00-00-16D7/18]
Institute of Ceramics and Building Materials
University of Lodz and Lodz Institutes of the Polish Academy of Sciences
elaboration of data (synthesis and modification of hydroxyapatite
elaboration of data (in vitro cell analysis)
writing and editing original draft preparation
writing and wditing original draft preparation
P.Sz.: synthesis and modification of hydroxyapatite
P.: conceptualization of biological analyses
K.R.: conceptualization of biological analyses
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DOI: https://doi.org/10.1038/s41598-023-42271-2
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Removing organics from hybrid nanostructures is a crucial step in many bottom-up materials fabrication approaches
It is usually assumed that calcination is an effective solution to this problem
This assumption has led to its application in thousands of papers
We here show that this general assumption is incorrect by using a relevant and highly controlled model system consisting of thin films of ligand-capped ZrO2 nanocrystals
while Raman spectroscopy fails to detect the ligands after calcination
elastic backscattering spectrometry characterization demonstrates that ~18% of the original carbon atoms are still present in the film
By comparison plasma processing successfully removes the ligands
Our growth kinetic analysis shows that the calcined materials have significantly different interfacial properties than the plasma-processed counterparts
Calcination is not a reliable strategy for the production of single-phase all-inorganic materials from colloidal nanoparticles
even though full etching can be accomplished in 6 h with optimized processing parameters
</a>Difference between calcination and plasma processing
Schematic of the resulting microstructure after the ligand removal in colloidal nanoparticle assemblies (CNAs) by calcination and plasma processing
Optimized conditions allow for similarly effective etching in as little as 6 h
</a>Effect of calcination on the C–H bond content
a Raman spectra of the ZrO2 CNAs before and after calcination at 300
and 12 h showing a reduction in the C–H content with increasing temperature
b The integral of the C–H Raman peaks for unprocessed and calcined CNAs with time
The plot shows a sharp decrease in the C–H content in the first 1 h of calcination followed by a plateau
They might originate from decomposition intermediates which decompose or oxidize at higher temperatures
Since most thin films are calcined at temperatures ranging between 300–700 °C for times ranging between 3 and 4 h, we conducted EBS on samples calcined at 400 °C for 5 h and 800 °C at 12 h (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/articles/s41467-017-02267-9#Fig3">3a</a>)
The data clearly show a sharp peak at the 185th channel in the calcined samples
indicating significant concentrations of carbon
The area of the carbon peak is smaller for the 800 °C sample than for the 400 °C sample
which is consistent with the Raman spectroscopy results
The elimination of smaller molecules also leads to the formation of bonds and crosslinking in the remaining chain
The residual crosslinked material is richer in carbon
elimination of smaller hydrogenated molecules like methane
through chain scission and formation of unsaturated bonds can explain the increased C:H ratio and the reduction of the C–H peaks
reduces the number of carbon atoms by 97% (1.5 at.%)
A smaller fraction of hydrogen is removed (82%)
Phosphorus and zirconium (not shown) are unaffected by either treatments
The thickness of the CNA films is expressed in TFUs because EBS does not consider pores
the TFUs can be used as a measure of the CNA thickness
The plot indicates that carbon is uniformly distributed throughout the thickness of the films in all the calcination and plasma processing conditions
Our data do not support the existence of a gradient
which would be expected if diffusion inside the film is the kinetically limiting step
The higher carbon concentration at the surface of the films is due to adventitious carbon
</a>Surface characterization and growth kinetics during calcination
a SEM micrographs of the top surface of the unprocessed
Plasma processing produces smooth films compared to calcination
though the disordered structure of the film resists catastrophic cracking
b Crystallite size as a function of time at different calcination temperatures with Ostwald model fit curves
c Arrhenius plot of the rate constants of grain growth
Eighty grams of TOPO was taken in a three-neck round bottom flask with a condenser attached to the middle neck and septa on the side necks
The TOPO was liquefied under argon and then degassed under vacuum at 80 °C for 30 mins with constant stirring
20 mmol of zirconium (IV) chloride and 16 mmol of zirconium (IV) isopropyl alcohol complex was added to the liquefied TOPO and temperature of the mixture was raised to 340 °C under an argon flow
After holding the reaction mixture for 2.5 h at 340 °C under argon blanket
the temperature was lowered to 80 °C and then diluted with toluene in a 1:1 ratio
The nanoparticles were then cleaned with acetone by centrifugation and dispersed in hexane
Spincoated CNAs were calcined in a furnace
The heating rate was maintained at 20 °C min−1
the samples were annealed to room temperature in the furnace at ~2 °C min−1
Raman spectroscopy measurements were performed using an XploRa Plus confocal Raman microscope (Horiba Scientific/JY
France) equipped with a 532-nm laser excitation source (11 mW at the sample)
Raman spectra were collected at three locations from the center of each film under ambient laboratory conditions using a 50× air objective (Olympus
The spectra were collected from 900 to 3300 cm−1 with a 1200 grooves/mm grating
Reported spectra were an average of 3 measurements
with a 120 s acquisition time for each spectrum
Scanning electron microscopy was performed with FEI quanta 250 field-emission SEM at both MARL and Department of Materials Science and Engineering at Iowa State University
Samples with poor conductivity were sputtered coated with 5 nm iridium before imaging
Imaging was done in secondary electron mode under high vacuum at 8 keV with beam spot size of 2.5
Transmission electron microscopy (TEM) and high resolution TEM images were obtained using 2007 JEOL 2100 200 kV STEM in TEM mode
This STEM is located at Microscopy and NanoImaging facility
Iowa State University and equipped with a Thermo Fisher Noran System 6 X-ray microanalysis system
Samples for TEM analysis were prepared by evaporating drops of dilute nanocrystals dispersion at room temperature
Energy dispersive X-ray (EDX) analysis were performed in STEM mode
Samples for EDX characterization were prepared by scraping off flakes of CNAs from the substrate using a sharp blade
and then attaching them on a carbon-coated TEM grid
The elemental analysis of the samples throughout the film depth was determined by combining non-Rutherford elastic backscattering spectrometry (EBS) and elastic recoil detection (ERD) using a helium beam
The samples were mounted on a sample plate on the 5-axis goniometer of the 2 MV Tandem accelerator
The scattering angle of the EBS detector was 170° and of the ERD detector 30°
For each measurement the beam incident angle was 70°
The filter in front of the ERD detector was a 24 µm thick foil of Kapton (C22H10O5N2; density of 1.42 g cm2)
The beam current on the samples during these measurements was ~20 nA with a beam spot of 1.5 mm by 1.5 mm
The MultiSIMNRA code enables the combination of multiple spectra by the optimization of an objective function calculated for all spectra
The final depth profile emerges from the optimization algorithm as the model that best describes all experimental data simultaneously
The main advantage of the self-consistent approach is that the information contained in one spectra plays as boundary condition during the optimization of all the others
The geometrical straggling was taken into account for all simulations
and for the ERD simulations the multiple scattering was also calculated
The data that support the findings of this study are available in the article
and from the corresponding author upon reasonable request
Building materials from colloidal nanocrystal assemblies: Molecular control of solid/solid interfaces in nanostructured tetragonal zro2
In SFPE Handbook of Fire Protection Engineering Vol 2
and Loss of Subsurface Ice on Mars: Experiments and models (California Institute of Technology
in 23rd International Conference on the Application of Accelerators in Research and Industry-CAARI 2014 Vol
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The work described in this paper has been supported by the Member-Specific-Research-Intel program of Semiconductor Research Corporation under Award No
The Raman measurements were supported by the U.S
and Biosciences through the Ames Laboratory
The Ames Laboratory is operated for the U.S
Department of Energy by Iowa State University under Contract No
XCT is grateful for a scholarship from the Chinese Scholarship Council
Department of Materials Science &amp; Engineering
Iowa State University of Science and Technology
Instituto de Física da Universidade de São Paulo
Department of Chemical &amp; Biological Engineering
and processed the nanoparticles and performed XRD
collected and interpreted Raman measurements; F.N
analyzed diffusion in the CNA and wrote the paper; L.C
The authors declare no competing financial interests
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DOI: https://doi.org/10.1038/s41467-017-02267-9
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In order to deal with the arising environmental issues across the globe at present nano particles with unique properties laid a benchmark in the name of nano catalysis
In this work the significance of calcination temperature on the thermal
structural and surface properties of a nano catalyst produced by sol–gel method using ultrasonic radiation against the disposal of toxic textile pollutants is studied in detail
The extract of tea leaves has been used as a bio-template during the synthesis to revise the crystallite size
and rate of agglomeration of nano sized grains by regulating their physico-chemical and surface properties
The influence of calcination in the transformation of single phased anatase titania to mixed phase anatase–rutile titania and the corresponding outcome in its photocatalytic activity employed in water treatment applications have been verified
The nano catalyst obtained is characterized by X-ray diffraction (XRD)
Fourier transform infrared spectroscopy (FT-IR)
UV–Vis diffused reflectance spectroscopy (DRS-UV–Vis) etc
The mesoporosity of the particle was examined using Barrett Joyner Halenda (BJH) model
The enhanced photo catalytic efficiency (about 97.7%) of templated nano titania due to calcination is verified against Congo red
The nano catalyst produced can be easily separated
recycled to support its economic feasibility
acetic acid and demineralized water used in the synthesis of titania particles were purchased from Sigma Aldrich
Tea leaf extract (TLE) was obtained from India Mart in the form of powder
Congo red dye was obtained from Sigma Aldrich
HCl and NaOH were of Fischer Scientific make
About 0.01&nbsp;mol of TTIP was mixed with 0.25&nbsp;mol of iso propanol and sonicated for 15&nbsp;min to ensure complete dissolution
To the clear solution obtained about 0.05&nbsp;mol acetic acid and 1&nbsp;g of leaf extract were added and sonication was continued for 30 more minutes to obtain a clear sol
The resulting sol was kept static for 12&nbsp;h to get a gel
The gel was dried in oven at 110&nbsp;°C overnight and calcined at different temperatures 400&nbsp;°C
600&nbsp;°C and 800&nbsp;°C for 5&nbsp;h and named as NT1
Nano titania sample without calcination is designated as NT
In order to determine the crystallize size and phase purity of the synthesized catalyst samples
XRD diffractogram was obtained using an X-ray diffractometer which recorded radiation in the range of 2θ from 20° to 80° at a scan rate of 2°&nbsp;min−1 using Cu Kα (λ = 1.546A°) radiations at room temperature
Study of FT-IR was performed with Perkin-Elmer using KBr pellet technique where the samples were exposed to scanning between 4000 and 400&nbsp;cm−1
UV–visible diffused reflectance spectroscopy analysis using Schimadzu with BaSO4 as a reference was implemented on the synthesized catalysts
The energy of the band gap was determined using the formula Eg = hc/λ and measured using Tauc equation
usually n = 2 for directly allowed transitions
The surface area and pore size distribution were examined by BET and BJH analysis using Quadrasorb surface analyzer with respect to nitrogen adsorption–desorption isotherms
So as to analyze the morphology and elemental composition of the synthesized catalysts
Quanta 200 ESEM electron microscope equipped with energy dispersive micro analysis was employed
phase transition and other chemical phenomenon during the thermal decomposition of the synthesized catalyst sample was determined using SDT Q 600 V8
Aurora TOC analyzer was used to estimate the degree of mineralization of Congo red from the total organic carbon (TOC) content
</a>XRD patterns of (a) NT (b) NT1 (c) NT2
</a>Nitrogen adsorption–desorption isotherm of (a) NT, (b) NT1, (c) NT2 and (d) NT3.
</a>Pore size distribution curves of (a) NT1 (b) NT2 (c) NT3 and (d) NT
</a>(a) Variation of Zeta Potential with pH (b) DLS pattern of NT and NT1 samples
</a>TEM image (a) and (b)&nbsp;SAED pattern of NT1.
</a>Particle size distribution histogram of NT1
The photo catalytic efficiency of the synthesized sample was verified against Congo red
by irradiating 100&nbsp;ml of dye solution containing specific quantity of templated NT samples under sunlight during 12 noon to 1&nbsp;pm in the month of June
The intensity of sunlight was monitored using digital lux meter (HTC make Digital Lux meter
The change in concentration of Congo red during the process of photo degradation was followed using UV–Vis Spectro photometer (Lambda 35
Perkin Elmer) at its absorbance maximum of 497&nbsp;nm
</a>Degradation of Congo red with and without photo catalyst (Initial concentration = 20&nbsp;µM
</a>Absorbance spectrum of photo degradation of Congo red dye solution by NT1 (initial concentration = 20&nbsp;µM
</a>Mechanism of photocatalysis by NT1 catalyst under irradiation
</a>TOC removal efficiency of NT1 (initial concentration = 20&nbsp;µM
</a>Effect of calcination temperature of NT1 on the photo degradation of Congo red [Congo red] = 20&nbsp;µM
</a>Effect of Catalyst Dosage on the photo degradation of Congo red [Congo red] = 20&nbsp;µM
</a>Effect of pH on the photo degradation of Congo red [Congo red] = 20&nbsp;µM
</a>Effect of Initial dye concentration on the photo degradation of Congo red dye solution (pH = 4
</a>Kinetic study of photo degradation of Congo red using NT1
</a>Overall QY of the samples at pH = 4 using Argon as purging gas
</a>Recycling of photo degradation of Congo red solution using NT1
The influence of calcination temperature over the formation
properties and photo catalytic activity of leaf extract templated nano titania samples by sol–gel technique was explored clearly in this work
The profound influence of calcination along with an organic template is evidenced from the optical
crystallite surface and morphological properties of synthesized titania samples
Among the titania samples prepared NT1 (calcined at 400&nbsp;°C)
with maximum surface area (98.6&nbsp;m2&nbsp;g−1) and minimum crystallite size (18&nbsp;nm) has exhibited 97.7% photo degradation of Congored in the visible light region due to bathochromic shift resulted in
The sample NT2 (calcined at 600&nbsp;°C) of both anatase and rutile phases also displayed excellent photo degradation about 96.5% against Congored under Sun light
clearly indicated the synergistic effect of mixed phases in extending the absorption edge to the visible light region
the observed experimental results of the present work highlighted the significant impact of calcination in tuning photo catalytic ability of bio-templated titania samples which can be further explored in the field of sensing
self-cleaning and anti-fouling coatings in future apart from photo catalytic applications
Visible light driven photocatalytic activity of TiO2 nanoparticles prepared via gel-combustion process
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Solar photo catalytic degradation of a reactive azo dye in TiO2-suspension
An overview on the photocatalytic degradation of azo dyes in the presence of TiO2 doped with selective transition metals
Water purification by semiconductor photocatalysis
Quantum yield with platinum modified TiO2 photocatalyst for hydrogen production
Effect of supporting and hybridizing of FeO and ZnO semiconductors onto an Iranian clinoptilolite nano-particles and the effect of ZnO/FeO ratio in the solar photodegradation of fish ponds waste water
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N.S.—Corresponding author contributed to the main text writing part of the manuscript. S.M.D.—Contributed in preparing origin curves, tiff images and figures. S.A.D.—Contributed in preparing Table <a data-track="click" data-track-label="link" data-track-action="table anchor" href="/articles/s41598-021-80997-z#Tab1">1</a>, Scheme <a data-track="click" data-track-label="link" data-track-action="" href="/articles/s41598-021-80997-z#Sch1">1</a>
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DOI: https://doi.org/10.1038/s41598-021-80997-z
Germany: France-based Fives has won a contract to build a 50t/day clay calcination unit at Rohrdorfer’s Rohrdorf cement plant in Bavaria
The unit will integrate into the plant’s clinker line in order to allow it to test the production of limestone calcined clay cement with up to 40% reduced CO2 emissions
Fives’ clay calcination unit uses a flash calcination process
Rohrdorfer’s Net Zero Emissions Labs team is responsible for the project to decarbonise the Rohrdorf cement plant by 2038
Its managing director Helmut Leibinger said “After a detailed technical review
we decided that the flash calciner with an integrated clay calcination unit from Fives FCB was the best solution in terms of reliability
We are confident that the unit will be essential in moving forward on our pathway to net zero.”
Conservation and RecyclingCitation Excerpt :Therefore
the potential of electrification in cement production is controlled by the degree of decarbonisation the power generation achieves
causing a higher uncertainty regarding the final emission reduction
The calculated decarbonisation potential of electrification (∼30% reduction) is roughly consistent with early results from research on solar energy for raw materials calcination
which showed a 48% potential reduction in climate change impacts where solar calcination was employed instead of conventional (petroleum coke based) calcination (Tomatis et al.
3 shows similar or slightly higher GHG emissions compared to those reported in the literature
mainly due to differences in the foreground unit process data used
Too many automated requests from this network
Science of the Total EnvironmentCitation Excerpt :Wu et al
(2022) found the emission intensity of cement production in China decreased from 708 kg CO2/t to 548 kg CO2/t from 2000 to 2020 (Li et al.
Facing with the challenge of net-zero emission in cement production
carbon capture/storage and clinker substitution are proposed to solve the CO2 issue raised by carbonate decomposition (Scrivener et al.
(2019) established a novel limestone calcination process with CO2 looping and recovery
where around 780 kg CO2 can be reduced for every ton of lime production (Jiang et al.
Journal of Cleaner ProductionCitation Excerpt :The CO2 adsorption performance of the material is the most important factor; however
the environmental impact of the manufacturing process should be considered to reduce the production of pollutants in total step
various studies have been conducted to manufacture the material with cleaner methods (Jiang et al.
Considering the additional pollutant generation during the manufacturing process or the regeneration conditions for recycling the material
the manufacturing process of zeolite is relatively clean compared to other materials
and the simplified surface treatment has less possibility of additional environmental pollution
Construction and Building MaterialsCitation Excerpt :In order to address this problem
a number of sustainability studies have been focused on (i) the efficiency of calcination processes and how these can be improved or (ii) environmental-friendly energy sources for such process
An example is the use of alternative fuels for recirculation and recovery of carbon dioxide (CO2) emissions [16]
limestone extraction and processing remains a key environmental problem [17] as it creates forests stripping
<a href="/articles/s41598-022-17277-x/metrics" data-track="click" data-track-action="view metrics" data-track-label="link" rel="nofollow">Metrics details</a>
Processing of spodumene ores requires calcination as a compulsory pre-treatment to convert α-spodumene to a more reactive β-spodumene phase
This transformation takes place at an elevated temperature of above 900 °C and results in a 30% volumetric expansion of the mineral and the product having highly altered physical properties
This work examines these induced properties and the effect of calcination on lithium grade deportment with particle size
XRD analysis showed a significant amount of β-spodumene in the calcined finest fraction (i.e
A marked reduction in the bond ball mill work index of the calcined lithium samples (i.e
42.3%) was recorded supporting the observed fracturing and friable appearance of the sample following α to β-spodumene conversion
The deportment of lithium to finer fractions was significantly increased when the sample was calcined
indicating selective breakage of the spodumene over gangue minerals
Beneficiation of lithium from spodumene is not a simple process because of similar properties of lithium-bearing minerals (i.e
spodumene) and their associated gangue minerals i.e
microcline (KAlSi3O8) and muscovite (KAl2(Si3Al)O10(OH,F)2)
A microscopic study reveals α-spodumene as a compact material composed of multiple layers stacked over each other
many cracks can be observed on particles leading to a more random crystal structure
Based on the significant and potentially selective change in physical properties of spodumene the objective of this work is to investigate the implications of calcination on behaviour of the samples during comminution and grade deportment by size (coarse gangue rejection)
different comminution techniques were used for calcined spodumene samples: crushing
The reason is that different comminution techniques result in varied particle size distributions and hence different grade deportment by size
crushing produces the coarsest fractions while semi-autogenous grinding generates the finest fractions
It should be noted that although it is understood that calcination of the whole ore would involve a marked increase in energy usage
the potential for separation and upgrading for challenging ores or mineralised waste streams is of interest
The ore samples were calcined for 1 h at 1100 °C in a muffle furnace (Cupellation furnace
The holding time of one hour allowed complete conversion of spodumene from α-phase to β-phase for accurate results
The calcined and non-calcined samples were used to understand the influence of calcination on comminution operations (crushing
autogenous milling or semi-autogenous milling)
The mill had a low-ball loading (10%) in contrast to standard ball milling (50%) and thus the mill was used to simulate a semi-autogenous grinding mill
where \({m}_{p} \, \mathrm{and } \, {m}_{f}\) are the mass of the product and the feed, respectively; \({g}_{p}\) and \({g}_{f}\) are the lithium grade in the product and the feed.
Crushing was performed using a cone crusher (Wescone
Australia) with a motor power of 9.2 kW; the closed side setting of the crusher is 3 mm
Semiautogenous and autogenous grinding were performed using a mill (the motor power of 1 kW) for 20 min
Semiautogenous grinding was conducted using 12 grinding balls (each grinding ball had 27.3 mm in diameter) that had a total mass of 1060 g; the rotational speed of the mill was 70 rpm
The calcined ores were investigated using crushing
where the screen size required for 80% of a product or a feed to pass through the screen are P80 and F80
respectively; F80 and P80 were 1700 µm and 53 µm
G is the ore grindability and S is the sieve size through which ore passes
Mineralogical analyses of the lithium ore samples were conducted using an Olympus BTX™ II Benchtop (Co-Kα) X-ray diffractometer (XRD)
The XRD experiments were performed using two calcined finest fractions (−0.6 mm) and two non-calcined coarsest fractions (+ 3.35 mm) considering that these samples had the maximum lithium content
This is very important to identify changes in the crystalline structure of spodumene before and after calcination
Figure <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/articles/s41598-022-17277-x#Fig2">2</a> also shows that the lowest mass retention for the largest size fraction was when the ore was calcined followed by cone crushing. Similar trends were also obtained in the case of the PF sample. However, in the case of the PF (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/articles/s41598-022-17277-x#Fig2">2</a>b)
calcination followed by semi-autogenous grinding had more mass retention of the largest size fraction than calcination followed by autogenous grinding
The smallest mass in the largest size fraction was obtained after calcination and cone crushing; the reason could be that the calcined ore was more brittle and thus more easily crushed than treated by autogenous grinding or semi-autogenous grinding
</a>Influence of calcination and comminution methods on cumulative grade of lithium in the case of (a) TDMS and (b) PF
The calcination impact on coarse gangue rejection in the case of the PF sample (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/articles/s41598-022-17277-x#Fig3">3</a>b) was similar to that in the case of the TDMS (Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/articles/s41598-022-17277-x#Fig3">3</a>a)
the lithium grade in the finest fraction was significantly higher when semi-autogenous grinding was conducted after calcination than that when cone crushing and autogenous grinding were performed after calcination
</a>Influence of calcination and comminution methods on cumulative lithium recovery in the case of (a) TDMS and (b) PF
</a>Cumulative grade vs cumulative recovery of lithium in the case of (a) TDMS and (b) PF
</a>XRD for two calcined finest fractions (−0.6 mm) and two non-calcined coarsest fractions (+ 3.35 mm)
</a>Influence of calcination on the cumulative grade of lithium in the case of (a) feed of the ball mill and (b) product of the ball mill.
</a>Influence of calcination on cumulative recovery of lithium in the case of (a) feed of BBMWI and (b) product of BBMWI in the case of PF
The energy consumed, Q, during calcinations of spodumene is obtained using the energy balance i.e. Equation (<a data-track="click" data-track-label="link" data-track-action="equation anchor" href="/articles/s41598-022-17277-x#Equ3">3</a>):
The energy consumed during calcination was 582 kWh/t or 2096 kJ/kg
calcination before grinding resulted in increased overall energy consumption
the furnace consumes vastly more energy than the comminution circuit
It is important to highlight that the main objective of this paper is not to develop a new flowsheet but to investigate the implications of calcination on behaviour of the samples during comminution and grade deportment by size (coarse gangue rejection)
This paper studies the influence of calcination of spodumene ore and comminution circuits on coarse gangue rejections by screening
The results showed that the calcination made spodumene brittle
having a positive effect on coarse gangue rejection by increasing lithium grade and recovery in the finest fraction
This effect was observed when the sieve size was in the range between 0.6 and 5 mm as well as 0.063 and 1 mm
The results of this work display the significantly altered properties of calcined material that promote preferential breakage of the spodumene over other components
Semi-autogenous grinding after calcination generated significantly more fines than autogenous grinding or crushing after calcination in the case of the PF sample
The energy consumed during the bond ball mill work test of the calcined ores was 42% less than that of the non-calcined ores
It must be noted that the reduction in comminution energy does not account for the additional energy consumption in calcining feed streams rather than concentrates
Fawthrop, A. Global Lithium Demand to More Than Double by 2024, Say Analysts. <a href="https://www.nsenergybusiness.com/news/industry-news/global-lithium-demand-2024/" data-track="click_references" data-track-action="external reference" data-track-value="external reference" data-track-label="https://www.nsenergybusiness.com/news/industry-news/global-lithium-demand-2024/">https://www.nsenergybusiness.com/news/industry-news/global-lithium-demand-2024/</a>
α→γ→β-phase transformation of spodumene with hybrid microwave and conventional furnaces
The beneficiation of lithium minerals from hard rock ores: A review
Mechanical enrichment of converted spodumene by selective sieving
Novel process for the extraction of lithium from b-spodumene by leaching with HF
Mineralogical transformations of spodumene concentrate from Greenbushes
The crystal structure of LiAlSi2O6-II (β-spodumene)
Nonlinear aging of cylindrical lithium-ion cells linked to heterogeneous compression
in: The AusIMM Comminution Handbook Carlton: AusIMM
Method of Extracting Lithium Values from Spodumene Ores
Phase transformation mechanism of spodumene during its calcination
Experimental deformation of sintered albite above and below the order-disorder transition
Mineral Processing Handbook (Int Student's ed.
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The collaboration between the authors would not have been possible without the financial support from CRC ORE
CRC ORE is part of the Australian Government’s CRC Program
which is made possible through the investment and ongoing support of the Australian Government
The CRC Program supports industry-led collaborations between industry
The Bald Hill Mine (Alliance Mineral Assets Limited
Western Australia) is acknowledged for the provision of samples for all the experiments
Financial support from Curtin University for this research work is appreciated
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DOI: https://doi.org/10.1038/s41598-022-17277-x
Coordination Chemistry ReviewsCitation Excerpt :The calcination of alum sludge at higher temperatures (500 °C) oxidized the aluminum oxide
the adsorption of As (V) was reduced to a significant extent [78]
These results suggest that aluminum oxide acts as a promising adsorbent material for the removal of arsenic from contaminated water
Chemical Engineering JournalCitation Excerpt :These modification and improvement strategies include but not limited to doping with metal elements like Sn
sensitizing with photosensitizers like organic dyes and quantum dots [136–142]
coupling with other semiconductors like CdS
or encapsulating carbon materials like nanotubes and graphene [151–154]
a lot of efforts were put to increase the specific surface area via altering TiO2′s morphology into nanofibers
hierarchical spheres and hollow nanoparticles [155–158]
the higher solar light utilization of TiO2 could be achieved by doping modification and heterojunction construction
which could extend light absorption region and improve the charge separation efficiency [159–165]
All content on this site: Copyright © 2025 Elsevier B.V., its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies. For all open access content, the relevant licensing terms apply.
Volume 9 - 2021 | <a class="ArticleLayoutHeader__info__doi" href="https://doi.org/10.3389/fenrg.2021.748665">https://doi.org/10.3389/fenrg.2021.748665</a>
high-temperature thermochemical energy storage system based on endothermic-exothermic reversible gas-solid reactions for application in concentrated solar power and industrial thermal processes
It consists of an array of tubular reactors
each containing an annular packed bed subjected to radial flow
and integrated in series with a thermocline-based sensible thermal energy storage
is selected as the reversible thermochemical reaction for the experimental demonstration
Synthetized 4.2&#x000a0;mm-mean size agglomerates and 2&#x000a0;mm-mean size granules of CaO with 42 %wt sintering-inhibitor MgO support attained reaction extents of up to 84.0% for agglomerates and 31.9% for granules
and good cycling stability in pressure-swing and temperature-swing thermogravimetric runs
A lab-scale reactor prototype is fabricated and tested with both formulations for 80 consecutive carbonation-calcination cycles at ambient pressure using a temperature-swing mode between 830&#x000b0;C and 930&#x000b0;C
The reactor exhibited stable cyclic operation and low pressure drop
and yielded specific gravimetric and volumetric heat storage capacities of 866&#x000a0;kJ/kg and 322&#x000a0;MJ/m3 for agglomerates
and 450&#x000a0;kJ/kg and 134&#x000a0;MJ/m3 for granules
current technologies based on sensible and latent heat storage are limited in temperature by materials constraints and in energy storage density by their specific heat capacity and enthalpy of phase change
we present the engineering design of a thermochemical reactor for the combined sensible-thermochemical TES system which features several intriguing advantages such as high specific heat storage capacity and low pressure drop
A lab-scale reactor prototype was fabricated and tested using the CaO/CaCO3 calcination-carbonation reversible reaction at temperatures around 900&#x000b0;C
The synthesis and characterization of the solid material to avoid sintering and enable cyclic stability is presented
The experimental setup and the performance of the reactor prototype for multiple consecutive cycles are described in detail
Left: Schematic cross-section of the TES system
comprising a layered thermochemical heat storage (TCS) unit on top of a sensible heat storage (SHS) unit
Right: Schematic cross-section of a single reactor tube of the TCS unit
&#x00394;H&#x000b0;298K &#x0003d; 178&#x000a0;kJ/mol CO2; &#x00394;G&#x000b0; &#x0003d; 0&#x000a0;at&#x000a0;T &#x0003d; 1167&#x000a0;K
was selected as a model reaction among the various screened metal oxides, hydroxides, sulfides, and carbonates (<a href="#B3">Andr&#x000e9; et al., 2016</a>), because of its safe handling, reasonably fast reaction rates in both directions, operating temperature in the range 800&#x02013;1,000&#x000b0;C, and additionally because it is a well-known reaction from the cement manufacturing. <a href="#F1">Figure 1B</a> shows the cross-section of a single reactor tube of the TCS unit
an annular packed bed of solid reactants/products CaO/CaCO3
and a concentric porous inner tube permeable to the gaseous reactant/product CO2
This inner tube has a single gas connection on one side for the inlet/outlet of CO2
which is transported across the porous tube walls to/from the packed bed
fluid flow is uniform across the packed bed and the pressure drop is kept low
the reactor is partially evacuated to lower the equilibrium temperature
thereby favouring the endothermic calcination of CaCO3 into CaO
while CO2 evolved is stored outside the reactor
CO2 is pumped back under higher pressure to the packed bed to increase the equilibrium temperature
thereby favouring the exothermic carbonation of CaO into CaCO3
The reaction extent is defined for each direction as:
Reaction extents for agglomerates and granules over 30 consecutive carbonation-calcination cycles
performed in the TGA using a temperature-swing between 830&#x000b0;C and 930&#x000b0;C with dwell times of 30&#x000a0;min
It is observed that the boundary of the agglomerate becomes less porous after cycling
while the morphology of the granule remains relatively unchanged
SEM images of agglomerate before (top left) and after cycling (top right)
and granules before (bottom left) and after cycling (bottom right)
The lab-scale TCS reactor prototype is schematically shown in <a href="#F5">Figure 5</a>
The main body consists of a 76.1&#x000a0;mm-outer diameter
3.2&#x000a0;mm-thickness cylindrical shell made of Inconel 600 and a concentric 13.5&#x000a0;mm-outer diameter
2&#x000a0;mm-thickness porous gas-feeding tube made of alumina (Rauschert Rapor P20)
These concentric tubes contain the annular packed bed of reactants with an active volume of 364&#x000a0;cm3
enclosed on both sides by Al2O3 insulation disks which also hold the central tube in place
Blind flanges fixed with clamps close off the reactor on both sides
Steel tubes are welded concentrically in both flanges
connecting the reactor to the rest of the setup
The reactor is placed in a tubular electric furnace (Carbolite HST 12/200) with a homogeneous heating zone of 200&#x000a0;mm
&#x000b1; 1.5&#x000b0;C) are inserted axially to measure the temperature distribution in the packed bed in the radial direction
They are positioned centrally in longitudinal direction and in a horizontal plane at radii of 10.8
25.8 and 30.8&#x000a0;mm from the centerline
Two additional shielded thermocouples measure the reactor shell temperature and the outlet gas temperature
Schematic cross-section of the experimental TCS reactor consisting of an Inconel shell
The piping and instrumentation diagram of the complete experimental setup is shown in <a href="#F6">Figure 6</a>
The experimental procedure starts with purging the reactor by vacuum pumping to 100&#x000a0;mbar followed by perfusing with CO2 from a gas bottle (purity 99.995%)
the gas bag (Restek gas sampling bag RT-22968) begins to fill
The gas composition is monitored by mass spectrometery (Pfeiffer OmniStar GSD 320 O1)
This purging cycle is to verify that no impurities are left in the system
the manual valves connecting the system to the gas supply and the mass spectrometer/vacuum pump are closed
The furnace then drives the carbonation and calcination cycles
The unidirectional low pressure drop mass flowmeter (Bronkhorst F-201CV
&#x000b1; 1% FS at 4&#x000a0;Ln/min) is embedded in a valve assembly that ensures that the flow is always in the same direction
independent of the current carbonation/calcination state
The LabView control system detects a state change automatically dependent on mass flow and temperature gradient changes
Piping and instrumentation diagram of the experimental setup
The dashed box indicates the system configuration during normal operation
The TCS reactor is operated in a temperature-swing mode under ambient pressure CO2
While the use of a gas bag ensures constant ambient pressure
the pressure in the reactor center is constantly monitored to verify that no significant pressure drop is occurring between the two
the only measured input variable is the prescribed temperature profile within the reactor and the only measured output is the CO2 mass flow rate in/out of the reactor
standard liters per min L/min) as a function of time
Green and red backgrounds indicate the carbonation and calcination steps
Positive volume flows correspond to CO2 flow into the reactor during the carbonation step; negative values correspond to the outflow during the calcination step
Representative measurement of a single calcination-carbonation cycle for agglomerates
performed in the TCS reactor using a temperature-swing between 830&#x000b0;C and 930&#x000b0;C
Reactor modelling indicates that the reaction extent is locally approaching chemical equilibrium, such that mass and heat transfer effects are dominating (<a href="#B26">Wild and Steinfeld, 2021</a>)
The relatively slow reaction rates observed are mainly attributed to the poor heat transfer rate of the packed bed
which is predominantly driven by conduction across the porous medium
This rate-controlling mechanism is strongly dependent on the effective thermal conductivity of the packed bed
which in turn depends on the morphology of the solid reactants
and can impose an upper size limitation on the radial thickness of the annular packed bed
the upscaling foresees the use of an array of tubular reactors
each containing an annular packed bed with radial thickness of comparable magnitude as the one of the prototype reactor
Multiple Cycles&#x02014;Experimental runs with 80 consecutive carbonation/calcination cycles were conducted for both agglomerates and granules using a temperature swing between 830&#x000b0;C and 930&#x000b0;C with a duration of 93&#x000a0;min for each step
Since shrinking had been observed with the fresh synthetized material
the reactants were cycled for over 80 cycles beforehand
and 102.72&#x000a0;g of granules were loaded into the reactor
The theoretical maximum CO2 volume corresponds to 23.23 and 17.92&#x000a0;L (standard liters)
Gas volumes were used to determine the reaction extent
<a href="#F8">Figure 8</a> shows the measured carbonation and calcination reaction extents for both formulations
the mean difference between &#x003c7;calcination and &#x003c7;carbonation was 0.57% for agglomerates and 0.41% for granules
a linear degradation by about 0.44% per cycle is observed from cycle &#x00023;15 to &#x00023;45 and by 0.2% per cycle from cycle &#x00023;45 to &#x00023;80
The reaction extent decreased from a maximum &#x003c7;calcination &#x0003d; 68.5% for cycle &#x00023;6
corresponding to a measured uptake/release CO2 volume of 15.91&#x000a0;L
to a minimum &#x003c7;calcination &#x0003d; 44.1% for cycle &#x00023;80
the granules exhibited superior cyclic stability but still some degradation by about 0.09% per cycle
from the initial maximum &#x003c7;calcination &#x0003d; 39.5% for cycle &#x00023;1
to &#x003c7;calcination &#x0003d; 27.4% for cycle &#x00023;80
the degradation observed was 35.4% for agglomerates and 30.4% for granules
Reaction extents for agglomerates and granules over 80 consecutive carbonation-calcination cycles
performed in the TCS reactor using a temperature-swing between 830&#x000b0;C and 930&#x000b0;C with dwell times of 93&#x000a0;min
the calculated specific gravimetric and volumetric heat storage capacities were 866&#x000a0;kJ/kg and 322&#x000a0;MJ/m3 for agglomerates
The higher energy densities of the agglomerates (both volumetric and gravimetric) came at the cost of poor stability over consecutive cycles
The granules exhibited very good cycling stability over 30 consecutive cycles in the TGA
but degradation was observed over 80 consecutive cycles in the reactor
This is attributed primarily to heat and mass transfer effects in the packed bed reactor vis-a-vis a single layer of granules and shorter cycle duration in the TGA
These detrimental effects could be mitigated under pressure-swing isothermal operation
An upper limit to the pressure drop in radial direction across the packed bed was calculated based on Darcy&#x02019;s law using values of permeability &#x003ba;&#x0003d;4.086&#x022c5;10&#x02212;13&#x000a0;m2 and &#x003ba;I&#x0003d;5.675&#x022c5;10&#x02212;8&#x000a0;kg&#x022c5;Pa&#x02212;1&#x022c5;s&#x02212;2 determined in a separate experiment
Assuming radial velocity of 0.0017&#x000a0;m/s at the inner boundary of the packed bed (corresponding to the highest measured values of the mass flow rate at 0.42&#x000a0;L/min)
the maximum pressure drop for agglomerates over the complete bed is 31&#x000a0;mbar
confirming the low pressure drop for this radial flow configuration of the TCS reactor
The TCS reactor is modular and scalable in a cross-flow heat exchanger configuration
can be operated in both temperature-swing and pressure-swing cyclic modes
and can be combined in series with a thermocline-based sensible heat storage
When applied to store concentrated solar heat
it enables the decarbonization of several key energy-intensive industrial processes such as metallurgical processing and cement manufacturing
as well as the efficient thermal production of solar power and fuels
The raw data supporting the conclusion of this article will be made available by the authors
MW and AS conceived the process and associated thermochemical reactor; MW and LL synthetized the materials
and processed the experimental data; AS supervised the project; all authors contributed to the writing of the manuscript
We gratefully acknowledge the financial support by the Swiss National Science Foundation (Project No
and Julian Urech for the technical support with the material synthesis
experimental setup and experimental campaign
A Critical Review of Thermochemical Energy Storage Systems
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L&#x000fc;&#x000f6;nd L and Steinfeld A (2021) Experimental Investigation of a Thermochemical Reactor for High-Temperature Heat Storage via Carbonation-Calcination Based Cycles
Received: 30 July 2021; Accepted: 17 September 2021;Published: 06 October 2021
Copyright &#x000a9; 2021 Wild, L&#x000fc;&#x000f6;nd and Steinfeld. This is an open-access article distributed under the terms of the <a rel="license" href="http://creativecommons.org/licenses/by/4.0/" target="_blank">Creative Commons Attribution License (CC BY).</a> The use
&#x0002a;Correspondence: Aldo Steinfeld, <a id="encmail">YWxkby5zdGVpbmZlbGRAZXRoei5jaA==</a>
<a href="/articles/s41598-023-39325-w/metrics" data-track="click" data-track-action="view metrics" data-track-label="link" rel="nofollow">Metrics details</a>
Lead-contaminated wastewater causes toxicity to aquatic life and water quality for water consumption
so it is required to treat wastewater to be below the water quality standard before releasing it into the environment
duck eggshell powder mixed iron (III) oxide-hydroxide (DPF)
and calcinated duck eggshell powder mixed iron (III) oxide-hydroxide (CDPF) were synthesized
and investigated lead removal efficiencies by batch experiments
CDPF demonstrated the highest specific surface area and pore volume with the smallest pore size than other materials
and they were classified as mesoporous materials
DP and DPF demonstrated semi-crystalline structures with specific calcium carbonate peaks
whereas CDP and CDPF illustrated semi-crystalline structures with specific calcium oxide peaks
the specific iron (III) oxide-hydroxide peaks were detected in only DPF and CDPF
Their surface structures were rough with irregular shapes
and chloride were only found in DPF and CDPF
and DPF and CDPF were also found Fe–O from adding iron (III) oxide-hydroxide
and CDPF illustrated the highest lead removal efficiency
DP and CDP corresponded to the Langmuir model while DPF and CDPF corresponded to the Freundlich model
All materials corresponded to a pseudo-second-order kinetic model
they could be reusable for more than 5 cycles for lead adsorption of more than 73%
CDPF was a potential material to apply for lead removal in industrial applications
it recommends removing lead from wastewater under the water quality standard which does not exceed 0.2 mg/L following USEPA standards before releasing it into the environment
duck eggshells also need to improve efficiency to deal with a high lead strength concentration in industrial wastewater
Many modification methods which are pyrolysis, calcination, acid or alkaline treatment, and metal oxides have been used to improve material efficiencies of food wastes for heavy metal removals reported in Table <a data-track="click" data-track-label="link" data-track-action="table anchor" href="/articles/s41598-023-39325-w#Tab2">2</a>
both the calcination process and adding metal oxides have been popularly used for increasing the adsorption capacity of heavy metal adsorbents
it is an interesting point to improve duck eggshell efficiency by using a calcination process or adding iron (III) oxide-hydroxide to confirm whether these two methods increase lead removal efficiency
no one to modify duck eggshell material with a calcination process along with adding iron (III) oxide-hydroxide
this study is the first effort to synthesize duck eggshell materials with or without a calcination process or adding iron (III) oxide-hydroxide
to compare their lead removal efficiencies through batch experiments
and verify whether using a calcination process or the addition of iron (III) oxide-hydroxide increases material adsorption capacity
and calcined duck eggshell powder mixed iron (III) oxide-hydroxide (CDPF) were synthesized and characterize their specific surface area
and chemical functional groups by Brunauer–Emmett–Teller (BET)
Field emission scanning electron microscopy and focus ion beam (FESEM-FIB) with energy dispersive X-ray spectrometer (EDX)
and Fourier transform infrared spectroscopy (FT-IR)
The point of zero charges and lead removal efficiencies of DP
and CDPF by batch experiments with varying doses
linear and nonlinear adsorption isotherms of Langmuir
and Dubinin-Radushkevich models were used to determine their lead adsorption patterns
and intraparticle diffusion models were used to identify their rates and mechanisms for lead adsorptions
the desorption experiments were used to confirm material reusability
Duck eggshells used in this study are wastes from the local restaurants in Khon Kaen province
Ferric chloride hexahydrate (FeCl3·6H2O) (LOBA
and they were analytical grades (AR) without purification before use
1% NaOH and 1% HNO3 were used for pH adjustments
</a>The synthesis methods of (a) duck eggshell powder (DP) and calcined duck eggshell powder (CDP) (b) duck eggshell powder mixed iron (III) oxide-hydroxide (DPF) and calcined duck eggshell powder mixed iron (III) oxide-hydroxide (CDPF)
duck eggshells were washed with tap water to eliminate contaminations
and then they were dried overnight in a hot air oven (Binder
they were ground and sieved in size of 125 µm
they were kept in a desiccator before use called duck eggshell powder (DP)
Thailand) in an air atmosphere at 900 °C for 3 h
and then they were kept in a desiccator before use called calcined duck eggshell powder (CDP)
5 g of DP or CDP were added to 500 mL of Erlenmeyer flask containing 160 mL of 5% FeCl3·6H2O
and they were mixed by an orbital shaker (GFL
they were filtrated and air-dried at room temperature for 12 h
they were added to 500 mL of Erlenmeyer flask containing 160 mL of 5% NaOH
and they were mixed by an orbital shaker of 200 rpm for 1 h
they were filtered and air-dried at room temperature for 12 h
they were kept in a desiccator before use called duck eggshell powder mixed iron (III) oxide-hydroxide (DPF) or calcined duck eggshell powder mixed iron (III) oxide-hydroxide (CDPF)
Various characterized techniques were used for characterizing duck eggshell powder (DP)
and calcined duck eggshell powder mixed iron (III) oxide-hydroxide (CDPF)
Japan) by isothermal nitrogen gas (N2) adsorption–desorption at 77.3 K and degas temperature of 80 °C for 6 h was used to identify their specific surface area
an X-ray diffractometer (XRD) (PANalytical
UK) in a range of 2θ = 5–80° was used for investigating their crystalline structures
Field emission scanning electron microscopy and focus ion beam (FESEM-FIB) with energy dispersive X-ray spectrometer (EDX) (FEI
USA) which the samples were placed on aluminum stubs with gold-coating for 4 min using a 108 auto Sputter Coater with thickness controller MTM-20 model (Cressington
USA) by analyzing at 10 kV accelerating voltage was used for studying their surface morphologies and chemical compositions
Fourier transform infrared spectroscopy (FT-IR) (Bruker
Hong Kong) in a range of 600–4000 cm−1 with a resolution of 4 cm−1 and 16 scans over the entire covered range was used for determining their chemical functional groups
0.1 g of duck eggshell material was added to 250 mL Erlenmeyer flasks containing 50 mL of each 0.1 M NaCl solution
Germany) at room temperature at 150 rpm for 24 h
the final pH value of the sample solution was measured by a pH meter (Mettler Toledo
Switzerland) and ∆pH (pHfinal – pHinitial) was calculated
A point that is the crosses line of ∆pH versus pHinitial equal to zero is the value of the point of zero charges (pHpzc)
where C0 is the initial lead concentration (mg/L)
and Ce is the equilibrium of lead concentration in the solution (mg/L)
15 g/L of DP or 10 g/L of DPF or 7.5 g/L of CDP
or 5 g/L of CDPF were added to 500 mL Erlenmeyer flasks with initial lead concentrations from 10 to 70 mg/L
The control condition of DP or DPF or CDP or CDPF was a sample volume of 200 mL
or 5 g/L of CDPF were added to 1000 mL of breaker with the initial lead concentration of 50 mg/L
The control condition of DP or DPF or CDP or CDPF was a sample volume of 1000 mL
where qd is the amount of lead desorbed (mg/mL) and qa is the amount of lead adsorbed (mg/mL)
</a>The physical characteristics of (a) duck eggshell powder (DP)
(b) duck eggshell powder mixed iron (III) oxide-hydroxide (DPF)
and (d) calcined duck eggshell powder mixed iron (III) oxide-hydroxide (CDPF)
</a>The crystalline formations of (a) duck eggshell powder (DP)
</a>The surface morphologies and the distributions of EDX mapping of (a,e) duck eggshell powder (DP)
(b,f) duck eggshell powder mixed iron (III) oxide-hydroxide (DPF)
and (d,h) calcined duck eggshell powder mixed iron (III) oxide-hydroxide (CDPF)
and Cl were increased similar reason to DPF from chemicals used in the CDPF synthesis
</a>FT-IR spectra of (a) duck eggshell powder (DP)
</a>The point of zero charges of duck eggshell powder (DP)
</a>Batch experiments on the effects of (a) adsorbent dosage
and (d) initial lead concentration of duck eggshell powder (DP)
The contact times from 1 to 6 h of duck eggshell powder (DP), duck eggshell powder mixed iron (III) oxide-hydroxide (DPF), calcined duck eggshell powder (CDP), and calcined duck eggshell powder mixed iron (III) oxide-hydroxide (CDPF) were applied for the effect of contact time, and the results are shown in Fig. <a data-track="click" data-track-label="link" data-track-action="figure anchor" href="/articles/s41598-023-39325-w#Fig7">7</a>b
Their lead removal efficiencies increased with increasing of contact time
and the highest lead removal efficiency is found at the constant contact time
Their highest lead removal efficiencies were 98.96% at 4 h for DP
they were used as the optimum contact time of DP
Lead removal efficiencies at 50 mg/L of DP
and CDPF demonstrated a higher lead removal efficiency than others
respectively were the optimum conditions in dose
so CDPF demonstrated the highest lead removal efficiency at high lead removal of 99.24% than other materials because it spent less material dosage and contact time than others
they could be arranged in high material efficiency to low being CDPF &gt; CDP &gt; DPF &gt; DP
adding iron (III) oxide-hydroxide along with the calcination process improved material efficiency
and CDPF was a potential material to apply in the wastewater treatment system
and (e) nonlinear adsorption isotherms of duck eggshell powder (DP)
(f) duck eggshell powder mixed iron (III) oxide-hydroxide (DPF)
and (h) calcined duck eggshell powder mixed iron (III) oxide-hydroxide (CDPF) for lead adsorptions
the Langmuir maximum adsorption capacities (qm) of DP
and Langmuir adsorption constants (KL) of DP
Freundlich adsorption constants (KF) of DP
the maximum adsorption capacities (qm) of DP
and the activity coefficient (KDR) values of DP
and CDPF on the linear Langmuir model were 0.996
and their R2 values on the linear Freundlich model were 0.939
and CDPF on the linear Temkin model were 0.977
and their R2 values on the linear Dubinin-Radushkevich model were 0.941
and CDPF on the nonlinear Langmuir model were 0.998
and their R2 values on the nonlinear Freundlich model were 0.942
and CDPF on the nonlinear Temkin model were 0.979
and their R2 values on the nonlinear Dubinin-Radushkevich model were 0.955
and CDPF on the nonlinear Langmuir model were 0.997
and their R2adj values on the nonlinear Freundlich model were 0.930
and CDPF on the nonlinear Temkin model were 0.975
and their R2adj values on the nonlinear Dubinin-Radushkevich model were 0.946
</a>Graphs of (a) linear pseudo-first-order
(c) linear elovich model (d) linear intraparticle diffusion
and (e) nonlinear kinetic models of duck eggshell powder (DP)
and CDPF on a pseudo-first-order kinetic model were 2.641
and their reaction of rate constants (k1) were 0.016
and their reaction of rate constants (k2) were 0.014
and their extents of surface coverage (β) were 1.619
and CDPF on the linear pseudo-first-order were 0.988
and their R2 values on the linear pseudo-second-order kinetic models were 0.996
and CDPF on the linear elovich model were 0.961
and their R2 values on the linear intraparticle diffusion model were 0.799
and CDPF on a pseudo-first-order kinetic model were 2.850
and their reaction of rate constant (k1) were 0.017
and their reaction of rate constants (k2) were 0.017
and their extents of surface coverage (β) were 1.644
and CDPF on the nonlinear pseudo-first-order kinetic model were 0.984
and their R2 values on the nonlinear pseudo-second-order kinetic model were 0.998
and CDPF on the nonlinear elovich model were 0.963
and their R2 values on the nonlinear intraparticle diffusion model were 0.795
and CDPF in the nonlinear pseudo-first-order kinetic model were 0.983
and their R2adj values in the nonlinear pseudo-second-order kinetic model were 0.997
and CDPF in the nonlinear elovich model were 0.961
and their R2adj values in the nonlinear intraparticle diffusion model were 0.783
</a>The desorption experiments of (a) duck eggshell powder (DP)
</a>Possible mechanisms of lead adsorption on (a) duck eggshell powder (DP)
(c) duck eggshell powder mixed iron (III) oxide-hydroxide (DPF)
and calcined duck eggshell powder mixed iron (III) oxide-hydroxide (CDPF) were successfully synthesized
so the calcination process along with adding iron (III) oxide-hydroxide helped to increase specific surface area and pore volume with decreasing pore size which supports a high lead adsorption
all materials were classified as mesoporous materials with a range pore size of 2–50 nm
DP and DPF demonstrated the semi-crystalline structures with specific calcium carbonate peaks
whereas CDP and CDPF illustrated the semi-crystalline structures with specific calcium oxide peaks
the specific iron (III) oxide-hydroxide was detected in only DPF and CDPF because of the addition of iron (III) oxide-hydroxide
Their surface morphologies were rough with irregular shapes
and the additional iron (III) oxide-hydroxide did not affect changing their surface characteristic
and chloride (Cl) were only found in DPF and CDPF from using chemicals in a process of addition of iron (III) oxide-hydroxide
they also found iron distribution on DPF and CDPF surfaces
and chloride (Cl) were found only in DPF and CDPF which could be confirmed the successful addition of iron (III) oxide-hydroxide in both materials
and C–O were found in all materials similar found in other studies of eggshells
whereas Fe–O was only found in DPF and CDPF because of the addition of iron (III) oxide-hydroxide
so the calcination process and addition of iron (III) oxide-hydroxide increased pHpzc of materials
and their lead removal efficiencies were 98.35%
CDPF illustrated a higher lead removal efficiency than other materials because it spent less adsorbent dosage and contact time than DP
adding iron (III) oxide-hydroxide along with the calcination process improved material efficiencies for lead adsorption
the Langmuir model was the best-fit model for DP and CDP explained by a physical adsorption process
While the Freundlich model was a good fit model for DPF and CDPF described by a physicochemical adsorption process
a pseudo-second-order kinetic model was the best-fit model for all materials related to a chemisorption process with heterogeneous adsorption
all duck eggshell materials could reuse for more than 5 cycles for lead adsorption of more than 73%
all duck eggshell materials were high-potential materials for lead adsorption in an aqueous solution
and CDPF demonstrated the highest lead removal efficiency
CDPF was suitable to apply for industrial wastewater treatment applications in the future
the continuous flow study and the competing ions such as sodium (Na+) and magnesium (Mg2+) contaminated in real wastewater are recommended to study for confirming the specific lead adsorption by duck eggshell materials before applying in industrial applications
The datasets used and/or analyzed during the current study available from the corresponding author on reasonable request
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Efficient techniques for the removal of toxic heavy metals from aquatic environment: A review
Removal of lead from battery manufacturing wastewater by egg shell
The effect of extraction time on the physicochemical characteristics of nanocalcium powder from chicken and duck eggshells
Biosorption of lead (II) from aqueous solution using Cellulose-based Bio-adsorbents prepared from unripe papaya (Carica papaya) peel waste: Removal Efficiency
kinetics and isotherm analysis: Biosorption of lead (II) from aqueous solution
Efficacy study of recycling materials by lemon peels as novel lead adsorbents with comparing of material form effects and possibility of continuous flow experiment
Thermodynamic valorisation of lignocellulosic biomass green sorbents for toxic pollutants removal
Application of the response surface methodology in the removal of Cu2+ and Pb2+ from aqueous solutions using orange peels
Bio-sorption of a bi-solute system of copper and lead ions onto banana peels: Characterization and optimization
Removal of heavy metals from wastewater using pomegranate peel
Low cost biosorbent (Melon Peel) for effective removal of Cu (II)
Cadmium removal mechanisms from aqueous solution by using recycled lignocelluloses
Bio-sorption for tannery effluent treatment using eggshell wastes; kinetics
and lead adsorption studies of chicken eggshell powder and chicken eggshell powder-doped iron (III) oxide-hydroxide
LIBS and pXRF validation for the removal of Pb by bio-CaCO3 nanoparticles from contaminated water
The application of eggshells and sugarcane bagasse as potential biomaterials in the removal of heavy metals from aqueous solutions
Use of eggshell-catalyzed biochar adsorbents for Pb removal from aqueous solution
Biochars with excellent Pb(II) adsorption property produced from fresh and dehydrated banana peels via hydrothermal carbonization
Novel magnetic pomelo peel biochar for enhancing Pb(II) and Cu(II) adsorption: performance and mechanism
equilibrium and thermodynamic for Pb(II) removal using a hybrid adsorbent
Application of waste egg shell for adsorption of Cd(II) and Pb(II) ions to protect environment: equilibrium
Metal removal using chemically modified eggshells: Preparation
Application of activated eggshell as effective adsorbent in the removal of lead (II) ion from fertilizer plant effluent
Biosorption of Pb and Cu from aqueous solution using banana peel powder
Removal of cadmium(II) and lead(II) from water by chemically treated citrullus lanatus peels as biosorbent in cost effective way
Development of effective and sustainable adsorbent biomaterial from an agricultural waste material: Cu(II) removal
Corncob-supported aluminium-manganese binary oxide composite enhanced removal of cadmium ions
Powdered and beaded lemon peels-doped iron (III) oxide-hydroxide materials for lead removal applications: Synthesis
Synthesis and characterization of chicken eggshell powder coated magnetic nano adsorbent by an ultrasonic bath assisted co-precipitation for Cr(VI) removal from its aqueous mixture
Development and characterization of magnetic eggshell membranes for lead removal from wastewater
Sensitive voltammetric determination of cadmium at a carbon nanotubes/Fe3O4/eggshell composites modified carbon paste electrode
Decontamination of Cd2+ and Pb2+ from aqueous solution using a magnetic nanocomposite of eggshell/starch/Fe3O4
Functionalized porous nanoscale Fe3O4 particles supported biochar from peanut shell for Pb(II) ions removal from landscape wastewater
Chicken and duck eggshell beads modified with iron (III) oxide-hydroxide and zinc oxide for reactive blue 4 dye removal
The adsorption of gases on plane surfaces of glass
Kinetics of ammonia synthesis on promoted iron catalysts
The equation of the characteristic curve of activated charcoal
Modification of sugarcane bagasse with iron(III) oxide-hydroxide to improve its adsorption property for removing lead(II) ions
About the theory of so-called adsorption of soluble substances
Pseudo-second order model for sorption processes
Theory of adsorption from solutions of non electrolytes on solid (I) equation adsorption from solutions and the analysis of its simplest form,(II) verification of the equation of adsorption isotherm from solutions
Kinetics of adsorption carbon from solution
Powdered and beaded zeolite A from recycled coal fly ash with modified iron (III) oxide-hydroxide for lead adsorptions
Powdered and beaded sawdust materials modified iron (III) oxide-hydroxide for adsorption of lead (II) ion and reactive blue 4 dye
Synthesis characterization and lead removal efficiency of orange peel powder and orange peel powder doped iron (III) oxide-hydroxide
Evaluation of raw and calcined eggshell for removal of Cd2+ from aqueous solution
Modification and characterization of chicken eggshell for possible catalytic applications
Recommendations for the characterization of porous solids (Technical report)
Power of recycling waste cooking oil into biodiesel via green CaO-based eggshells/Ag heterogeneous nanocatalyst
Zeolite A powder and beads from sugarcane bagasse fly ash modified with iron(III) oxide-hydroxide for lead adsorption
Phosphorus removal in domestic wastewater treatment plant by calcined eggshell
Preparation and characterization of nano-CaO based on eggshell waste: Novel and green catalytic approach to highly efficient synthesis of pyrano [4
equilibrium and thermodynamic studies for the removal of lead ions from aqueous solutions by using low cost adsorbents: A comparative study
Adsorption of Lead (I) ions onto goethite chitosan beads: Isotherms
Synthesis of powdered and beaded chitosan materials modified with ZnO for removing lead (II) ions
Modified alginate beads with ethanol extraction of Cratoxylum formosum and Polygonum odoratum for antibacterial activities
Antibacterial activities against Staphylococcus aureus and Escherichia coli of extracted Piper betle leaf materials by disc diffusion assay and batch experiments
Comparative antibacterial activities of Garcinia cowa and Piper sarmentosum extracts against Staphylococcus aureus and Escherichia coli with studying on disc diffusion assay
Reactive blue 4 adsorption efficiencies on bagasse and bagasse fly ash beads modified with titanium dioxide (TiO2)
Comparative reactive blue 4 dye removal by lemon peel bead doping with iron (III) oxide-hydroxide and zinc oxide
Modified beaded materials from recycled wastes of bagasse and bagasse fly ash with iron (III) oxide-hydroxide and zinc oxide for the removal of reactive blue 4 dye in aqueous solution
Comparative lead adsorptions in synthetic wastewater by synthesized zeolite A of recycled industrial wastes from sugar factory and power plant
Efficient removal of heavy metals from aqueous solutions using a bionanocomposite of eggshell/Ag-Fe
Adsorptive capacity of calcinated hen eggshell blended with silica gel for removal of lead II ions from aqueous media: Kinetics and equilibrium studies
Adsorption of lead (Pb-II) using CaO-NPs synthesized by solgel process from hen eggshell: Response surface methodology for modeling
Evaluation of eggshell-rich compost as biosorbent for removal of Pb(II) from aqueous solutions
Preparation and application of granular bentonite-eggshell composites for heavy metal removal
Eggshell and coral wastes as low cost sorbents for the removal of Pb2+
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The authors are grateful for the financial support received from The Office of the Higher Education Commission and The Thailand Research Fund grant (MRG6080114)
Coordinating Center for Thai Government Science and Technology Scholarship Students (CSTS) and National Science and Technology Development Agency (NSTDA) Fund grant (SCHNR2016-122)
and Research and Technology Transfer Affairs of Khon Kaen University
Pimploy Ngamsurach &amp; Rattanaporn Tannadee
Environmental Applications of Recycled and Natural Materials (EARN) Laboratory
Pornsawai Praipipat &amp; Pimploy Ngamsurach
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DOI: https://doi.org/10.1038/s41598-023-39325-w
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Having powerful antibacterial and antioxidant effects
zinc oxide and manganese oxide nanomaterials are of great interest
Here we have synthesized manganese oxide decorated zinc oxide (MZO) nanocomposites by co-precipitation method
calcined at different temperatures (300–750 °C) and studied various properties
Here the crystalline structure of the nanocomposite and phase change of the manganese oxide are observed with calcination temperature
The average crystalline size increases and the dislocation density and microstrain decrease with the increase in calcined temperature for the same structural features
The formation of composites was confirmed by XRD pattern and SEM images
EDAX spectra proved the high purity of the composites
different biological properties change with the calcination temperature for different shapes
Nanomaterial calcined at 750 °C provides the best anti-microbial activity against Escherichia coli
Bacillus subtilis and Bacillus megaterium (gram-positive) bacterial strain at 300 µg/mL concentration
The nanomaterial with calcination temperatures of 300 °C and 450 °C provided better antioxidant properties
several metal oxide hybrid systems have been thoroughly explored
as potential materials for antibacterial applications
we synthesized manganese zinc oxide (MZO) nanocomposites
calcined at different temperatures within the range of 300–750 °C and studied their morphological
size and structural changes with the help of different characterization techniques
The biological efficacy of the synthesized complex was determined through antibacterial and antioxidant assays
The effectivity of the nanocomposites in the germination and growth of wheat seed (Triticum aestivum) was also studied in order to investigate their role in germination and subsequent plant growth
Ethylene glycol (EG) were provided by Merck (purity ≥ 98.9%)
These substances were all put to immediate use without being further refined
All studies were conducted using dried and cleaned glassware
10.7521&nbsp;g of Zn(NO3)2.6H2O was added to 200&nbsp;mL distilled water and stirred at 545&nbsp;rpm for 40&nbsp;min
50&nbsp;mL homogeneous solution of manganese sulfate (3.0003&nbsp;g MnSO4⋅H2O in 50&nbsp;mL distilled water and stirred for 20&nbsp;min) was added dropwise to the solution and stirred for 20&nbsp;min
Then 10&nbsp;mL ethylene glycol is added and stirred for another 20&nbsp;min
The pH of the solution was adjusted to ~ 9 using NaOH solution
Then the total solution was stirred for 2&nbsp;h and dried to get nanopowder
the structures of the synthesized nanomaterials were examined using an X-ray diffractometer (XRD) with a Bruker D8 Advance diffractometer and Cu Kα (λ = 1.5418&nbsp;Å)
A Perkin-Elmer Paragon 1000 FT-IR spectrometer was used to record FTIR spectra across a specific range of 450–4000&nbsp;cm−1 at ambient temperature
To examine the surface morphologies of nanocomposites and average grain sizes
SEM pictures were acquired using a JEOL JSM-5800 working at an accelerating voltage of 10&nbsp;kV
Energy dispersive X-ray spectroscopy (EDAX) (Hitachi SU8010 Series) was employed for the elemental analysis
the antibacterial activity of test compounds was evaluated against five bacterial strains including Escherichia coli
Bacillus subtilis and Bacillus megaterium (gram-positive)
A loopful of each bacterial strain was inoculated in sterile nutrient broth and incubated for 24&nbsp;h at 37&nbsp;°C to get fresh and viable bacterial inoculum
After evenly mixing the test organism (200 µL of bacterial suspense) in a nutrient agar plate
The test compounds dissolved in DMSO to obtain a concentration of 100
Sterile paper disks impregnated with the test compounds were placed on the inoculated plates using sterile forceps and the plates were incubated at 37&nbsp;°C for 24&nbsp;h
The bactericidal effect of different grades of MZO nanocomposites was initially assessed using the highest concentration of the tested sample (300&nbsp;µg/mL) and only the effective grade of nanocomposites was further tested in different concentrations
The diameter of the inhibition zone was measured in millimeters using a ruler
The antioxidant efficacy of the tested samples was determined by calculating the inhibition percentage and the IC50 values
which represent the theoretical concentration of the tested sample at which 50% of the free radicals are scavenged
were used to express the antioxidant activity of the sample
Ac is the absorbance of the control and As is the absorbance of the tested sample
The ‘Sonalika’ cultivar of wheat was collected from National Seeds Corporation Limited
Collected seeds were surface sterilized with 4% sodium hypochlorite and then 500&nbsp;µg/mL of different grades of synthesized nanocomposites (i.e
MZ 3 and MZ 4) were applied through seed priming
The initial germination assay was carried out in Petri plates (200 seeds were taken) and based on germination percentage optimal grades of MZO nanocomposites were chosen
germinated seeds of optimal grade and control were transferred onto another Petri plate and seedlings were grown on nutrient-free sand under a natural photoperiod
The transplanted seedlings were maintained up to 20&nbsp;days after transplantation (DAT) and the optimal dose of MZO nanocomposite was applied two times (in solution form) between the period (7 DAT and 14 DAT)
and biochemical parameters were evaluated after harvesting the seedlings at 20 DAT
The shoot length was measured using a centimeter scale
whereas biomass was determined by using digital weight balance (Quintix 224
Growth parameters and plant biomass were calculated by taking readings from 20 replicas
and antimicrobial study three replications were taken into consideration and results were presented as average with standard deviation
Statistical differences were carried out by Tukey’s HSD test at p ≤ 0.05 (for the germination test) and a two-tailed t-test at 95% confidence level (plant growth and biochemical parameters)
</a>X-ray diffraction pattern of (a) all nanocomposites
The sharp peak of MZ 3 and MZ 4 confirms the high crystalline nature of the prepared sample and peak intensity increases with the increase in temperature
The average crystalline size can be calculated by using Scherer’s equation
</a>Initial screening of antibacterial activity of MZ 1
MZ 3 and MZ 4 at 300&nbsp;µg/mL against the tested microorganism
</a>Antibacterial activity of MZ 4 against the tested bacterial strain.
</a>Zone of inhibition of MZ 4 against different bacterial strain at different concentration
</a>Radar plot for comparative effect of MZ 1
MZ 3 and MZ 4 against different free radicals
(scale bar represents the IC 50 value in µg/mL)
</a>Germination percentage of wheat seed as influenced by different types of MZO nanocomposites
The vertical bar above column represents the standard deviation (n = 3)
c etc.) indicated that they are statistically different at p ≤ 0.05 following Tukey’s HSD test
</a>Phenotypic appearance (A) and growth attributes (B) of treated and control and treated wheat seedlings
The vertical bar above the column represents the standard deviation (n = 20)
Asterisk: symbol indicated that they are statistically significant from their respective control at 95% confidence level as observed through two-tailed t-test
we study the effects of calcination temperature on structural
anti-oxidant and seed germination processes
The prepared nanocomposites were characterized using different techniques like XRD
The characterization results showed that with the variation of calcination temperatures
the synthesized nanocomposite MZO transformed into different structures and sizes
At low calcination temperatures the composite exists as Zn1.41Mn1.59O4/ZnO and is converted into ZnMnO3/ZnO at higher calcination temperatures
The bioactivities are greatly influenced by the varied temperature
the bioactivities of the composite changes with the different calcination temperatures
Composite shows the best antibacterial at 750 0C and best antioxidant and seed germination properties at 300 0C indicating the temperature controlling activities are pronouncedly found in the nanocomposites giving a new way for future research
Data will be made available on request to the corresponding author
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Current knowledge on the oxidative-stress-mediated antimicrobial properties of metal-based nanoparticles
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Antibacterial and cytotoxicity activities of biosynthesized silver oxide (Ag2O) nanoparticles using Bacillus paramycoides
Green synthesis and antimicrobial efficacy of titanium dioxide nanoparticles using Luffa acutangula leaf extract
A mini review of antibacterial properties of ZnO nanoparticles
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Mn3O4 nanozymes boost endogenous antioxidant metabolites in cucumber (Cucumis sativus) plant and enhance resistance to salinity stress
Effect of foliar spray of zinc oxide on some antiox idant enzymes activity of sunflower under salt stress (2018)
Evaluation of the ecotoxicity of model nanoparticles
Effects of silver nanoparticle exposure on germination and early growth of eleven wetland plants (2012)
Morphological and proteomic responses of Eruca sativa exposed to silver nanoparticles or silver nitrate
Impacts of size and shape of silver nanoparticles on Arabidopsis plant growth and gene expression
Effect of nanosilver in wheat seedlings and Fusarium culmorum culture systems
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In Environmental Science and Pollution Research.1–20 (2023)
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and chemical quality of the common dry bean
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the authors are grateful to the Departments of Chemistry
Basak thanks the UGC for awarding her with a scholarship as Junior Research Fellow with reference number 272/(CSIR-UGC NET June 2017)
The authors are also thankful to SAIF-LPU for XRD and Saif-Panjab University for EDAX
Ghani Khan Choudhury Institute of Engineering and Technology (GKCIET)
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DOI: https://doi.org/10.1038/s41598-023-48695-0
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Triple-shelled ZnFe2O4 hollow microspheres (ZFO) as anode materials for lithium ion battery are prepared through a one-pot hydrothermal reaction using the composite solution consisting of sucrose in water and metal ions in ethylene glycol (EG)
followed by different calcination processes
The architectures of ZFO micro spheres are differently synthesized through a mutual cooperation of inward and outward ripening with three different calcination temperatures
Thin triple-shelled ZnFe2O4 hollow microspheres calcined at 450 °C (ZFO-450) delivers a high reversible capacity of 932 mA h g−1 at a current density of 2 A g−1 even at the 200th cycle without obvious decay
and 845 mA h g−1 at high current densities of 0.5
Thin triple-shelled hollow microsphere prepared at an optimum calcination temperature provides exceptional rate capability and outstanding rate retention due to (i) the formation of nanoparticles leading to thin shell with morphological integrity
(ii) the facile mass transfer by thin shell with mesoporous structure
and (iii) the void space with macroporous structure alleviating volume change occurring during cycling
This desirable architecture suitable for improving the electrochemical performance is largely governed by different calcination temperatures in preparing the multiple-shelled ZnFe2O4 hollow microspheres
we report the first fabrication of thin triple-shelled ZnFe2O4 hollow spheres using a one-pot hydrothermal technique of a solution involved with zinc
and sucrose leading to ZnFe-glycolate/carbon composite
followed by decomposition of core carbon at an optimum calcination temperature
The calcination temperature has a great effect on the transformation of triple-shelled ZnFe2O4 hollow structure so as to obtain excellent specific capacity and good electrochemical retention without any fading of rate capability
The tailored architecture with thin triple-shelled ZnFe2O4 hollow structure at an optimum calcination temperature provides the advantage in shortening the distance of mass transfer and sustaining the structural integrity
which leads to superior electrochemical performance delivering 932 mA h g−1 at a constant density of 2 A g−1 even at the 200th cycle
The diffraction peaks with the high crystallinity are stronger and sharper with the increase in crystal size
which depends on the formation of morphology by calcination temperature
The diffraction peaks of ZFO-450 are weaker and wider compared to those of ZFO-400 and ZFO-500
implying that the morphology of ZFO-450 is thin shell microsphere consisting of smaller crystalline
the diffraction peaks of ZFO-400 and ZFO-500 are sharper than those of ZFO-450
indicating the formation of thick-shelled microsphere comprising larger crystalline
</a>Schematic illustration for the synthesis of various shelled ZnFe2O4 hollow microspheres
and (c,f) ZFO-500 with different calcination temperatures; (g) STEM image and corresponding EDAX elemental mappings of Zn
the characteristics of the triple-shelled ZnFe2O4 hollow morphology are separately confirmed by the scanning transmission electron microscopy (STEM) and energy dispersive X-ray analysis (EDX) elemental mappings
</a>N2 adsorption-desorption isotherms and pore size distribution (inset) of ZFO-400
and (c) ZFO-500 at a current density of 2 A g−1 in 1 M LiPF6/EC/DMC
the ferrite molecule cannot be recovered and the reactions are progressed as follows:
the ZnFe2O4 phase is transformed to the Li0.5ZnFe2O4 phase (Region I) in the range of 1.5 to 0.85 V
and then Li0.5ZnFe2O4 phase is transformed to the Li2ZnFe2O4 phase in the range of 0.85 to 0.7 V (Region II)
The intense cathodic peak located at ∼0.47 V ascribes to the reduction of Fe3+
and Zn2+ to Fe0 and Zn0 and subsequent the formation of Li–Zn alloys and Li2O
the broad peak situated at ~0.47 V disappears in the following cycles
indicating the irreversible reaction caused by the formation of a solid electrolyte interface (SEI) layer inducing the consumption of excess lithium ion
one broad reduction peak is observed at 0.9 V
signifying the reversible reduction of amorphous Fe2O3 and ZnO (equations 8 and 9)
one strong oxidation peak is observed at 1.68 V
which are connected with the oxidation of Zn0 and Fe0 to Zn2+ and Fe3+
In the cathodic process of 2nd and the 3rd cycle
the main peaks shift to about 0.9 V; these shifts are deeply relevant to the easy polarization and the electrochemical reversibility after the initial cycles
The distinctions of main peaks to higher voltage are deeply associated with thin triple-shelled hollow microspheres with extremely mesoporous structure
Two anodic peaks in the third cycle also shift to around 1.73 V representing easy polarization
</a>Cycle performances and coulombic efficiencies (CE) of ZFO-400
and ZFO-500 at a current density of 2 A g−1
</a>Schematic illustration for the structural variation of triple-shelled hollow microspheres during lithiation/delithiation
</a>Rate performances of ZnFe2O4-450 at various current densities from 0.5 to 20 A g−1 in 1 M LiPF6/EC/DMC
the charge transfer resistance of ZFO-450 with thin triple-shelled hollow microsphere is decreased due to the improvement of the charge transfer process over the electrode surface
which is associated with abundant interparticle pore spaces and sufficient void spaces with larger specific surface area
The morphology of thin triple-shelled ZnFe2O4 hollow microsphere is well suitable for the remarkable improvement of the cycling capacity and rate capability
Thin triple-shelled ZnFe2O4 hollow microspheres (ZFO) were prepared by a one-pot hydrothermal technique and subsequent calcination process in air
and 25 mmol of sucrose (C12H22O11) were dissolved in 50 ml of H2O and 50 ml of ethylene glycol (EG: CH2OH)2
EG serves as dispersing reagent of metal precursors in a hydrothermal process
The resulting solution was then moved into 180 ml of poly(tetrafluoroethylene) (PTFE)-lined stainless steel autoclave
the sealed autoclave was reacted at 190 °C for 24 h
and then cooled down to room temperature in the autoclave
The obtained products were washed using distilled water several times
ZFOs were synthesized by calcining as-prepared precursors at 400
and 500 °C for 4 h at a heating rate of 2 °C min−1 in air
The obtained ZnFe2O4 hollow microspheres were denoted as ZFO-400
and ZFO-500 with different calcination temperatures
The surface morphologies of ZFOs were analyzed by the field emission scanning electron microscopy (FE-SEM
The nanostructured morphology and elemental mappings of ZFOs were scrutinized by the transmission electron microscopy (TEM
Netherlands) in the Korean Basic Science Institute (KBSI
The determination of crystallinity was investigated by the X-ray diffraction (XRD
The thermal characterization of ZFOs was illustrated by thermogravimetric analysis (TGA
JAPAN) at a ramping rate of 5 °C min−1 under air atmosphere
The porous characteristics of the samples were verified at 77 K in nitrogen atmosphere by the Brunauer-Emmett-Teller (BET
The electrochemical performances were carried out using coin cells (type CR2032)
The slurry was made by completely mixing 70 wt.% as-prepared active materials
The working electrodes were prepared by casting the slurry on the surface of copper foil and then dried at 120 °C for 12 h in a vacuum oven
The mass loading of ZFO on copper foil was accurately controlled around 0.80 mg cm−2
The coin cell was assembled in an Ar-filled glove box
Lithium foil was used as a counter and a reference electrode
The electrodes were separated by polypropylene films (Celgard® 2400)
The electrolyte was composed of a solution of 1 M LiPF6 in a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) (1:1
The specific charge and discharge performance of the ZFOs were carried out by using a battery cycler (WBCS 3000
Korea) with different current densities (0.5
The measurements by cycling voltammetry (CV) were carried out using an electrochemistry workstation (IM6e
Germany) ranging from 0.01 to 3.0 V at a scan rate of 0.5 mV s−1
The Nyquist plots as the results of electrochemical impedance spectroscopy (EIS) were expressed graphically by using an electrochemistry workstation (IM6e
Germany) in the range of 10 mHz to 100 kHz
We have successfully designed a noble architecture of thin triple-shelled ZnFe2O4 hollow microspheres (ZFOs) with mesoporous and macroporous morphology for lithium ion battery anodes with different calcination temperatures
The ZFOs is synthesized using ZnFe-glycolate/carbon microspheres obtained by a one-pot hydrothermal reaction
and decomposition of core carbon at an optimum calcination temperature
The preparation of ZFOs are mainly governed by a mutual cooperation of inward and outward ripening with different calcination temperatures
influencing on the formation of thin shells with mesoporous structure and wide void spaces with macroporous structure
The ZFO-450 provides superior electrochemical performance involving excellent rate capability and exceptional cycling retention
maintaining at 932 mA h g−1 at a high current density without any capacity fading at the 200th cycle
This rate capability is ascribed to thin triple-shelled hollow structure with well-developed mesoporous/macroporous structure
The ZFO with thin shells and wide voids creating a highly porous morphology offers a large number of electrochemically active sites
facilitates Li+ insertion/extraction inducing the improvement of rate capability and cycling stability
the wide void in thin ZFO-450 makes it easier to alleviate severe volume expansion standing against fast lithiation/delithiation without any pulverization
Effects of calcination temperature for rate capability of triple-shelled ZnFe2O4 hollow microspheres for lithium ion battery anodes
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A facile synthetic approach to reduced graphene oxide-Fe3O4 composite as high performance anode for lithium-ion batteries
A CTAB-assisted hydrothermal orientation growth of ZnO nanorods
Adaptable silicon–carbon nanocables sandwiched between reduced graphene oxide sheets as lithium ion battery anodes
An alumina stabilized graphene oxide wrapped SnO2 hollow sphere LIB anode with improved lithium storage
Synthesis and lithium storage properties of Co3O4 nanosheet-assembled multishelled hollow spheres
Fabrication of hierarchical porous MnCo2O4 and CoMn2O4 microspheres composed of polyhedral nanoparticles as promising anodes for long-life LIBs
Multi-shelled hollow micro-/nanostructures
A self-standing and flexible electrode of yolk-shell CoS2 spheres encapsulated with nitrogen-doped graphene for high-performance lithium-ion batteries
Controlled synthesis of hollow Co–Mo mixed oxide nanostructures and their electrocatalytic and lithium storage properties
Facile synthesis of hollow Cu2Sb@C core–shell nanoparticles as a superior anode material for lithium ion batteries
Ni) oxide nanoparticles on graphene sheets through Kirkendall effect as anodes for high-performance lithium-ion batteries
3D hierarchical porous α-Fe2O3 nanosheets for high-performance lithium-ion batteries
Formation of ZnMn2O4 ball-in-ball hollow microspheres as a high-performance anode for lithium-ion batteries
Hollow core–shell ZnMn2O4 microspheres as a high-performance anode material for lithium-ion batteries
Hollow activated carbon nanofibers prepared by electrospinning as counter electrodes for dye-sensitized solar cells
Dye-sensitized solar cells based on anatase TiO2 hollow spheres/carbon nanotube composite films
Multi-shelled MgCo2O4 hollow microspheres as anodes for lithium ion batteries
Nanostructured cerium oxide thin films by nebulized spray pyrolysis (NSP) technique: Impact of surfactants on the structural
A high-performance anode for lithium ion batteries: Fe3O4 microspheres encapsulated in hollow graphene shells
Coaxial carbon nanofiber/NiO core–shell nanocables as anodes for lithium ion batteries
Hierarchically mesoporous carbon nanofiber/Mn3O4 coaxial nanocables as anodes in lithium ion batteries
Accurate Control of Multishelled Co3O4 Hollow Microspheres as High-Performance Anode Materials in Lithium-Ion Batteries
Synthesis of Co2SnO4 hollow cubes encapsulated in graphene as high capacity anode materials for lithium-ion batteries
Template-free synthesis of VO2 hollow microspheres with various interiors and their conversion into V2O5 for lithium-ion batteries
Lithium storage in hollow spherical ZnFe2O4 as anode materials for lithium ion batteries
Graphene-wrapped CoS nanoparticles for high-capacity lithium-ion storage
Copper silicate hydrate hollow spheres constructed by nanotubes encapsulated in reduced graphene oxide as long-life lithium-ion battery anode
ZnFe2O4@C/graphene nanocomposites as excellent anode materials for lithium batteries
Cu2O-SnO/poly(3,4-ethylenedioxythiophene) nanocomposites with core-shell structures and their electrochemical characteristics
Dense core–shell structured SnO2/C composites as high performance anodes for lithium ion batteries
Reduction of the oxygen reduction reaction overpotential of nitrogen-doped graphene by designing it to a microspherical hollow shape
Porous graphene nanoarchitectures: An efficient catalyst for low charge-overpotential
and high capacity lithium−oxygen batteries
Impact of porous electrode properties on the electrochemical transfer coefficient
High capacity ZnFe2O4 anode material for lithium ion batteries
α-Fe2O3 nanoflakes as an anode material for li-ion batteries
Li-storage and cyclability of urea combustion derived ZnFe2O4 as anode for li-ion batteries
α-Fe2O3 multi-shelled hollow microspheres for lithium ion battery anodes with superior capacity and charge retention
Multilayered nanocrystalline SnO2 hollow microspheres synthesized by chemically induced self-assembly in the hydrothermal environment
In-situ crafting of ZnFe2O4 nanoparticles impregnated within continuous carbon network as advanced anode materials
Graphene anchored with ZnFe2O4 nanoparticles as a high-capacity anode material for lithium-ion batteries
Ultrahigh cycling stability and rate capability of ZnFe2O4@graphene hybrid anode prepared through a facile syn-graphenization strategy
Electrochemical properties of yolk-shell structured ZnFe2O4 powders prepared by a simple spray drying process as anode material for lithium-ion battery
Polypyrrole-coated zinc ferrite hollow spheres with improved cycling stability for lithium-ion batteries
Hierarchical TiO2 submicron-sized spheres for enhanced power conversion efficiency in dye-sensitized solar cells
Hollow porous SiO2 nanocubes towards high-performance anodes for lithium-ion batteries
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This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (no
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ENGINEERS are building a pilot plant to electrify production of a clinker replacement that would reduce emissions from cement production
Clinker is a key component of cement, and its production is estimated to be responsible for <a href="https://www.pbl.nl/sites/default/files/downloads/pbl-2020-trends-in-global-co2-and_total-greenhouse-gas-emissions-2020-report_4331.pdf">4% of global CO2 emissions</a>
Efforts are underway to find more environmentally-friendly replacements for clinker
and a new collaboration is taking a two-fold approach: it is producing a calcined clay that eliminates the CO2 emissions that would have been produced by the clinker it replaces
and it is looking to electrify the production process to further reduce fossil fuel use
The partnership includes process engineering firm FLSmidth
which has developed a flash calciner system
and chemical engineers at the Technical University of Denmark (DTU)
The partners will build a pilot plant at FLSmidth’s R&amp;D centre in Denmark that will involve integrating the flash calciner with a high-temperature electric heat generation technology developed by partner Rondo Energy
which contains a large proportion of clinkerA spokesperson told The Chemical Engineer that the potential savings depend on the raw materials used and would be lower where more additives and cleaner fuels are used
the team expects they can reduce emissions by a further 10%
though the electricity used will have to be from renewable sources
Following the results of the ECoClay pilot plant project
the partnership expects to begin construction of the first full-scale electric clay calcination installation by the end of 2025
said: “Calcined clay has no intrinsic – mineral process – emissions; by replacing the fuel combustion powering the calcination process with renewable electricity
the EcoClay partnership will deliver prompt
low-cost emissions reductions at scale – and can build the foundation for true-zero cement.”
Research engineers at DTU will develop the controls required for the electrified calcination process and energy storage systems so that it can flexibly respond to fluctuating electricity prices
said: “The significance of this partnership cannot be overestimated; ECoClay is accelerating the green transition of cement production – aiming to set a new future standard for the industry.”
A report by the European Climate Foundation in 2018 noted clinker replacement was a key option for reducing emissions <a href="/news/report-outlines-path-to-significantly-reducing-emissions-from-cement-industry/">in a report that outlined how CO2 emissions could be cut by 95% by 2050</a>. Last month, <a href="/news/cemex-invests-in-lower-carbon-cement-technology/">Cemex invested in Carbon Upcycling Technologies</a>
which has developed technology that uses clinker substitutes
Article by <a href="/authors/adam-duckett/">Adam Duckett</a>
<a href="/news/ceramic-pump-works-at-1-400-c/">Ceramic pump works at 1,400°C</a>
<a href="/news/uranium-under-the-sea/">Uranium: Under the sea</a>
<a href="/news/glass-industry-sketches-process-technology-route-for-reaching-net-zero/">Glass industry sketches process technology route for reaching net zero</a>
<a href="/news/uk-set-to-host-rare-earths-processing-hub-in-push-for-cleantech-security/">UK set to host rare earths processing hub in push for cleantech security</a>
<a href="/news/mof-capture-firm-secures-34m-funding-for-uk-ccs-pilot/">MOF capture firm secures £3.4m  funding for UK CCS pilot</a>
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