Grinding Step Research Articles

Enhancing cobalt recovery from Li-ion batteries using grinding treatment prior to the leaching and solvent extraction process

The growing of cobalt demand for electric vehicle batteries and various applications associated with the no cobalt ores makes the European Union consider it as a critical metal. This causes the search for new sources to meet the demand. Several studies have been explored battery recycling to promote the circular economy. On the one hand, acid leaching has been widely studied for cobalt recovery, but on the other hand, the grinding step is not well explored in the literature, which must increase metals release and further recovery. For this reason, the aim of the present work is to provide new insights on cobalt extraction from Li-ion batteries evaluating from the grinding step to the selective separation. Different grinding techniques were studied to ground the scrap: hammer, knife, and ceramic balls were evaluated on dismantling considering cobalt release. Ultrasound washing was evaluated to decrease the particle size distribution of ground material. Leaching experiments were carried out exploring different leaching agents (H2SO4, HNO3 and HCl with and without H2O2) and conditions (time, temperature and pH). Selective cobalt separation was performed using Cyanex 272 1 mol/L in kerosene. Results have shown that knife mill was the only one to ground the batteries. The best efficiency for cobalt leaching was obtained using H2SO4+H2O2 at pH 3.0 and 50 °C. Considering all hydrometallurgical processing – leaching-solvent extraction – 91 % of cobalt was recovered.

Development of genetically modified maize MIR604 matrix reference materials

<p indent="0mm">The safety supervision of genetically modified organisms (GMO) is the guarantee for the healthy development of the biotechnology, and the reference materials (RM) are the material basis for GMOs detection. The lack of RMs makes it difficult to ensure the accuracy, reliability and comparability of the test data. GM maize MIR604 is approved for import as a raw material in China. The safety supervision of GM maize MIR604 urgently requires to prepare RMs. The pure GM maize MIR604 matrix RMs were prepared through the steps of raw material identification, grinding, sieving and water content determination. The results of homogeneity test and stability test showed that the RMs in this batch had good homogeneity within the bottle and between the bottles, the property value of the RMs was stable, allowing them to be transported at room temperature for one month, as even for six months verified by the long-term stability test. The copy number ratio of the transgenic DNA to the total DNA was collaboratively characterized by nine laboratories using the duplex digital PCR of MIR604/<italic>Adh1</italic>. The certified value was 0.50. The various uncertainty components of the RM characterization results were fully evaluated, and the expanded uncertainty was combined to be 0.06 (copy/copy). The specification of RMs of this batch is <sc>1 g</sc> bottle^–1 and the minimum sample size is <sc>100 mg.</sc> This batch of RMs can be used in the fields of safety supervision and labelling of MIR604, and laboratory quality control.

Multi-Element Evaluation in Black Pepper (Piper nigrum L.) According to the Processing

Black pepper is one of the most consumed spices worldwide and the evaluation of trace elements content is essential to promote consumer safety. In this study, concentrations of the elements As, Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, Se, V and Zn was determined in samples of black peppercorn (n = 25) and ground black pepper (n = 25) to verify how processing affects element concentrations. The elements were determined by inductively coupled plasma mass spectrometry and flame atomic absorption spectrometry. A principal component analysis showed that Fe, Pb and V was influenced by the processing and ground black pepper samples showed higher levels for these elements than black peppercorn. Although specific legislation for spices is not available in Brazil, results indicated that Pb concentrations in two brands of the processed samples under investigation exceeded the maximum level established by Brazilian and European legislation for vegetables and fruits. These results point to the necessity to control the processing of the black pepper, especially the grinding step.

Residual stress change in multistage grinding

Although high efforts were made to get a deeper understanding of grinding processes for many years, it is still not possible to clearly predict the alteration of the workpiece surface layer caused by grinding. To achieve this objective, the material loads occurring during grinding and the material modifications remaining in the material have to be considered. This knowledge enables the concept of Process Signatures describing correlations between internal material loads and induced modifications. For the prediction of residual stresses occurring in a single step grindin process, various theoretical approaches can be derived. In most of these approaches, grinding processes are investigated considering the same initial state of the workpieces in terms of material, heat treatment but also in terms of functional properties such as the residual stress state generated by the previous manufacturing processes. The influence of different initial states on the residual stress state after grinding is still not clear but of high interest, taking into account that grinding is usually performed as a process consisting of multiple steps (multistage grinding). In this context, this paper focusses on the effect of different initial states that are generated in the first grinding step on the grinding process in the subsequent grinding step e.g. regarding the residual stress state. Correlations are identified between internal material loads and the residual stress in multistage grinding. To gain a deeper knowledge of the interaction between thermally and mechanically induced internal loads, the combined laser and deep rolling process is introduced. In contrast to grinding, this process allows the variation of the thermal and mechanical load independently from each other, so that acting mechanisms regarding materials loads and resulting material modifications can be revealed which serve to optimize the multistage grinding processes in the future.

The Mechanism of the First Hydration‐Dehydration Cycle of Pure α‐ and β‐CaSO4•0.5H2O

The objective of this research was to understand the dehydration mechanism of technical dihydrate and the variation of the physical properties of β‐hemihydrate after the first hydration‐dehydration process. In this study, the recycling mechanism of different hemihydrate types as raw material was investigated. The influence of the first hydration‐dehydration process on the hydration rate, microstructure, and mechanical properties of recycled hemihydrate were characterized by differential calorimetric analysis (DCA), calcium ion‐selective electrode (Ca2+‐ISE), conductivity, particle size distribution (PSD), scanning electron microscopy (SEM), and X‐ray diffraction (XRD). The results showed that the formed hemihydrate after the first hydration‐dehydration process differs in its properties than the unrecycled hemihydrate in some characteristics such as the morphological structure, number of surface, and side defects due to the grinding process after the first hydration step. In addition to the grinding step, the calcination process was responsible for increasing the number of defects on the crystal surface, which leads to a change in setting time and the microstructure of the recycled hemihydrate. Therefore, after the 1st reaction cycle of β‐HH, the compressive strength decreases due to a decrease in the hemihydrate crystal size, an increase in the surface area, and an increase in the amount of water required to perform the hydration reaction. The obtained hemihydrate after the first hydration‐dehydration process was in β form due to the applied calcination process after the first cycle.

Development of surface residual stress and surface state of 42CrMo4 in multistage grinding

Abstract In this study, cylindrical grinding of a 42CrMo4 (AISI 4140) steel with varied grinding sequence stages is analyzed regarding the effect of the different loads during multistage grinding up to the resulting final residual stress state and material structure. The grinding process was adjusted in a way to enhance the mechanical load with varying intensity and generate a pronounced compressive residual stress state in the final grinding step. Furthermore, consecutive multistage grinding processes were carried out and investigated. Using a mobile XRD system with a cos α method mounted on a robotic positioning arm, repetitive measurements of the ground surfaces were performed in the machine tool without sample removal, giving information about the surface residual stress development for each step of the process sequence. The information about the surface integrity development and possible effects of the grinding process during each step is relevant for the contact conditions and modification mechanisms which lead to the final surface integrity. It is shown that the final material state, normally accessible in post-process investigations, can also be achieved reliably by sequencing the process into several steps of a regular grinding process and depends strongly on the contact parameters in a non-linear way. It could be shown, that even the spark out step can lead to significant changes in the surface residual stress state.

LEAD RECOVERY FROM CRYSTAL GLASS SOLID WASTES

Crystal glass has many uses such as chandeliers and vases. Crystal glass contains lead oxide with a percentage varied from 8-30%. Some of such glass is wasted during preparation of crystal products. This waste is considered hazardous due to its content from leachable lead compounds. The aim of this work is to recover lead metal from solid waste generated from polishing and grinding step in crystal glass manufacture. Samples were collected and fused with sodium carbonate at 800-1000 °C for different periods up to 5 hours. Results revealed that heating decomposed lead compounds present in the waste to lead metal. 80 Wt. % of lead metal was recovered at activation energy ∆E= 45.2 k j/mol.

Review on Upgradation in Coal Flotation by Pretreatments

Flotation of low ranked/oxidized coal becomes difficult with oily collectors. The prime factor parts accounted by lessening in coal hydrophobicity are the occurrence of polar hydrocarbons groups (hydroxyl, carbonyl, phenol and peroxides) on the coal surface. The up-gradation in coal flotation has been achieved due to the enhancement in hydrophobicity by pretreatments. The dry coal is conditioned with the pretreatment steps of grinding, mixing/conditioning, ultra sound, thermal treatment, microwave and direct mixing of the chemical reagents prior to wetting. These are the pretreatments methods among them grinding, mixing/conditioning are contemplated to separate the oxidized film coating on the coal particles surfaces. The separations of impurities are also indicated from ultra-sonic treatment. The Separation of pore/hydration water and hydroxyl functional groups through coal surface is accounted by microwave and thermal pretreatments. The procedure regarding direct contact produce the oxidize coal evaded for collector deposit on coal surface. The interception generally rises from hydration carapace on coal surface; in this duration, coal surface is wetted by water. The present research study is highlighted to see the distinct pretreatment steps effects on the rate of coal flotation. It is a welcome result declaration with highly precise evaluation.

Constitutive Modeling of the Tensile Behavior of Recycled Polypropylene-Based Composites.

The effect of reprocessing on the quasi-static uniaxial tensile behavior of two commercial polypropylene (PP)-based composites is experimentally investigated and modeled. In particular, the studied materials consist of an unfilled high-impact PP and a talc-filled high-impact PP. These PP composites are subjected to repeated processing cycles, including a grinding step and an extrusion step to simulate recycling at the laboratory level, the selected reprocessing numbers for this study being 0, 3, 6, 9, and 12. Because the repeated reprocessing leads to thermo-mechanical degradation by chain scission mechanisms, the tensile behavior of the two materials exhibits a continuous decrease of elastic modulus and failure strain with the increasing amount of reprocessing. A physically consistent three-dimensional constitutive model is used to predict the tensile response of non-recycled materials with strain rate dependence. For the recycled materials, the reprocessing effect is accounted by incorporating the reprocessing sensitive coefficient into the constitutive model for Young’s modulus, failure strain, softening, and hardening equations. Our predictions of true stress—true strain curves for non-recycled and recycled 108MF97 and 7510—are in good agreement with experimental data and can be useful for industries and companies which are looking for a model able to predict the recycling effect on mechanical behavior of polymer-based materials.

Reactive Grinding Synthesis of LaBO3 (B: Mn, Fe) Perovskite; Properties for Toluene Total Oxidation

LaBO3 (B: Mn, Fe) perovskites were synthesized using a three-step reactive grinding process followed by a calcination at 400 °C for 3 h. The three successive steps are: (i) solid state synthesis (SSR); (ii) high-energy ball milling (HEBM); (iii) low-energy ball milling (LEBM) in wet conditions. The impact of each step of the synthesis on the material characteristics was deeply investigated using physico-chemical techniques (X-ray diffraction (XRD), N2-physisorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), temperature-programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS)) and the catalytic performances of the synthesized materials were evaluated for the toluene total oxidation reaction. Starting from single oxides, microcrystalline perovskite phase, exhibiting negligible surface areas, is obtained after the SSR step. The HEBM step leads to a drastic reduction of the mean crystal size down to ~20 nm, along with formation of dense aggregates. Due to this strong aggregation, surface area remains low, typically below 4 m2·g−1. In contrast, the second grinding step, namely LEBM, allows particle deagglomeration resulting in increasing the surface area up to 18.8 m2·g−1 for LaFeO3. Regardless of the perovskite composition, the performance toward toluene oxidation reaction increases at each step of the process: SSR &lt; HEBM &lt; LEBM.

Fine limestone dust from ornamental stone factories: A potential filler for a high-performance cementitious matrix

The benefits of using waste materials as supplementary cementitious materials (ASCMs) become greater as their use will minimize the chemical, biological and even visual pollutions caused when they are left in an unexploited form. For example, the estimated amount of industrial fine limestone dust (FLSD) released from ornamental stone factories is enormous. Accordingly, efficient recycling of these types of dusts in concrete provides many ecological and economic advantages. FLSD particles were found to have a spherical morphology due to the grinding and polishing steps used in the factories causing their emission. In this research, FLSD has been incorporated into different cement pastes. These pastes contained different replacement levels of 0, 15, 30 and 45% FLSD at various water-to-binder (W/B) ratios of 0.25, 0.35 and 0.45. They have been subjected to the effect of normal and sulfate attack conditions. The results showed that the paste mixture with a high FLSD replacement level did not demand for higher superplasticizer dosage in contrary to other types of dusts while gaining a high resistance to sulfate exposure. It has also been shown that the mixtures with 45% FLSD had the minimum deterioration due to sulfate effect. In addition, at a low W/B ratio of 0.25, the resistance to sulfate attack was significant, as confirmed using ultrasonic pulse velocity (UPV) and microstructure analyses. The mixture with W/B ratio of 0.25 and 45% FLSD has been deemed the optimum for the use in formulating high performance concrete. FLSD is proposed as a fine material with a high potential as a filler for HPC.

High Performance Silicon-Carbon Composite Powders Using Recycled Silicon from Solar Cells As Anode Material for Li-Ion Batteries

Currently, silicon (Si) coming from the recycling of solar cells is a non-valued fraction. The principal aim of this work is the development of silicon recovered during the dismantling of solar panels as negative electrode material for Li-ion batteries. The principal technological challenge associated with the use of silicon in this type of application is to control the volume expansion during charge/discharge cycles. This drawback can be avoided through the formation of Silicon/carbon composites in which the size of the silicon particles and their dispersion is controlled [1–4]. In this research, we develop a carbon matrix system using a conducting carbon source and a reduced carbon from organic source that will incorporate the silicon particles. The recycled Si wafers are leached to remove Al and Ag. The a grinding step is performed to obtain Si particles of <200nm and then a mixed suspension of Si, an organic carbon source and the conductive carbon source is prepared. This mixture is spray-dried followed by heat treatment to generate a carbon matrix that incorporates the silicon particles The morphology of the composite materials is analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The Electrochemical performance of Si/C composites is characterized by Galvanostatic charge-discharge cycling and electrochemical impedance spectroscopy (EIS).

Characterization of Zirconia-Based Ceramics After Microgrinding

Despite the recent developments of ductile mode machining, microgrinding of bioceramics can cause an insufficient surface and subsurface integrity due to the inherent hardness and brittleness of such materials. This work aims to determine the influence of a two-step grinding operation on zirconia-based ceramics. In this regard, zirconia (ZrO2) and zirconia toughened alumina (ZTA) specimens are ground with ultrasonic vibration assistance within a variation of the machining parameters using two grinding steps and different diamond grain sizes of the tools in each of the machining procedure. White light interferometry, scanning electron microscope, X-ray diffraction (XRD), and four-point bending tests are performed to evaluate surface roughness, microstructure, residual stresses, and flexural strength, respectively. The strategy applied suggests that the finished parts are suitable for certain biomedical uses like dental implants due to their optimum surface roughness. Moreover, concerning the mechanical properties, an increase of the flexural strength and compressive residual stresses of ground ZrO2 and ZTA workpieces were observed in comparison to the as-received specimens. These results, as well as the methodology proposed to investigate the surface integrity of the ground workpieces, are helpful to understand the bioceramic materials response under microgrinding conditions and to set further machining investigations.

Fujimi’s New SiC CMP Slurry Development

Introduction Since silicon carbide (SiC) is a very hard substrate and is stable both chemically and physically, wafer processing is costly and takes a lot of time. Particularly, in the chemical mechanical polishing (CMP) process, which is the final wafering process, significant improvement in performance such as surface quality and productivity is required for high volume commercial production. At Fujimi, we have developed a high removal rate slurry of over 1.5 μm per hour on the Si-face under neutral pH and conventional CMP processing conditions. We have also proven that the slurry had a nice behavior in removal rate performance based on Prenston equation, that is, removal rate was proportional to the pressure and velocity of substrate. Furthermore, our testing result has shown great surface morphology such as no scratches and no latent scratches beneath the surface. Low surface roughness was achieved under 0.1nm of RMS at 10x10μm area. Fujimi has introduced this new SiC slurry at the Advanced Industrial Science and Technology (AIST) as a suitable stock polishing slurry to remove surface damage coming from previous grinding or lapping steps. We have demonstrated the benefit of a two-step CMP process which applies a stock step using the higher removal rate slurry followed by a fine step using our Colloidal silica type slurry. As a result, the combination process could realize to produce the SiC epi-ready wafer with fine quality surface in shorter process time than conventional process [1]. Results and DiscussionIn this study, we will discuss our SiC slurry development technologies. At Fujimi, we can control the size and shape of the abrasive grains. Utilizing our expertise in chemical and additive formulation, we can modify our slurries to meet our customers’ various performance criteria. In Figure 1, it shows a test result example in which the removal rate of the Si-Face was improved. These improved performances depended on the type of additive used in the slurry. Test was performed using substrates of 4-inch 4H-N SiC (4°off) Si-face substrates with exactly the same polishing process and pad condition for all slurries. Slurry A was a result of high speed conventional slurry used by AIST [1] as a reference slurry. Slurry B was a newly developed slurry with improved abrasive grains dispersion. Slurry C was also a newly developed slurry focusing on the improvement of oxidation efficiency. As a result, it was possible to achieve a polishing removal rate over 2 um / hour as well as maintain low surface roughness at the same time. [1] S. Hirano et al., Journal of the Japan Society for Abrasive Technology, 60, (2016)353 Figure 1

The impact of fruit softening on avocado cell microstructure changes monitored by electrical impedance and conductivity for cold‐pressed oil extraction

AbstractThe impact of avocado fruit firmness on cold‐pressed oil recovery was investigated using a laboratory oil extraction unit. Intact, ground flesh and the malaxed (mixed) fruit pulp samples were collected during the extraction process to evaluate cell structure by electrical impedance spectroscopy, electrical conductivity, and light microscopy. The intact flesh of soft fruit at 105 firmometer value (Fv; over ripe) had the lowest electrical resistance compared to fruit with a firmness of 55 Fv (minimally ripe). The grinding step resulted in the greatest reduction in electrical resistance, suggesting the greatest cellular disruption in this step. Additionally, intact fruit and fruit pulp from fruit at 105 Fv had a higher conductivity and a lower electrical resistance value, which indicated more cell rupture occurred when softer, riper avocado fruit were processed. A greater number of unbroken parenchyma cells remained in samples from firmer fruit at various sampling points during the extraction process.Practical applicationsParenchyma cells in the mesocarp of soft ripe “Hass” avocado were easier to disrupt during cold‐pressed extraction. Extraction yield of oil, using the cold‐press method, increased with riper avocados. However, the cold‐pressed oil quality decreased with avocado fruit ripeness, based on percentage of free fatty acids and peroxide value. Electrical impedance spectroscopy (EIS) was found to be a useful technique for following mesocarp cellular changes during the extraction of oil.

Testing of life history traits of a soilborne pathogen in vitro: Do characteristics of oospores change according the strains of Aphanomyces euteiches and the host plant infected by the pathogen?

AbstractAphanomyces euteiches is a polyphagous, homothallic soilborne pathogen producing asexual (zoospores) and sexual (oospores) spores. Even if oospores are essential for disease development and survival, to date, no study has focused on the production rates of oospores or the quality of the offspring produced by oospores. In this study, a nonabrasive oospore extraction method from infected roots of leguminous species (pea, faba bean and vetch) was developed. This methodology includes steps of grinding and filtration. The quality of oospores (viable, dormant and dead) was assessed with tetrazolium bromide staining, and germination of oospores was tested using exudates of peas, faba bean and vetch. The average yield of the extraction method was approximately 21%. Staining revealed some differences between strains and between leguminous species. The germination percentage of oospores extracted from pea, faba bean and vetch was 25%, 62% and 70%, respectively, and a significant difference was observed according to the origin of A. euteiches‐inoculated strains. Application of exudates seems to stimulate the germination of oospores (2% for the control, 18% for pea exudates and 1% for vetch exudates). Differences observed between A. euteiches strains and leguminous species indicate that more knowledge concerning the biology of oospores is needed. This will help to better estimate evolution process of the pathogen and manage resistance and crop successions.

Electrostatic Stabilization and Characterization of Fine Ground Silicon Particles in Ethanol

Stirred media milling is a common method for the efficient production of nanoparticles. Here the grinding of semi-metallic silicon nanoparticles is presented, which are of special interest as anode material for next generation lithium-ion batteries. Ground silicon particles show an enormous reactivity in water due to particle etching but only surficial oxidization in alcoholic solvents, which inhibits further particle etching. Therefore, the grinding process was realized in ethanol as a solvent in order to avoid particle etching but allow good integrity to a water-based anode production later on. From the application point of view the colloidal stability of silicon nanoparticle suspensions is of great importance, to realize anode coating structures with fine disperse silicon nanoparticles. Hence, this study is focusing on the electrostatic stabilization of the silicon nanoparticles in ethanol, which was characterized by zeta potential and the agglomerate size measurements. These results corresponding to electrostatical interactions are also in good accordance with rheological characterization of the suspensions and theoretical calculations. Additionally, the final metallic silicon content was also of high interest for the application, so that a thermogravimetric analysis procedure was established and evaluated by a chemical pulping procedure according to DIN EN ISO 21068-2. Furthermore the impact of the chosen stabilization additive and the solvent purity on the silicon content are discussed. Finally the process is realized by a pre-grinding step in a planetary ball mill and a fine grinding step within a stirred media mill. With this setup a production route for suspensions with a median primary particle size of less than 150 nm and metallic silicon content above 80 wt.% of the particles is presented. The ground nanoparticles show a surficial oxidized shell with a silicon core and a flake-like shape with crystalline and amorphous regions.

Silica-coating of nano- $$\hbox {Y}_{3} \hbox {Al}_{5} \hbox {O}_{12}{:}\hbox {Ce}^{3+}$$ Y 3 Al 5 O 12 : Ce 3 + synthesized by self-combustion

$$\hbox {Y}_{2.91} \hbox {Ce}_{0.09} \hbox {Al}_{5} \hbox {O}_{12}$$ is obtained by self-combustion, grinding and sol–gel coating. X-ray diffraction, transmission electron microscopy, photoluminescence and absorption measurements were used to identify the structural and optical properties of each step of the process. The process is composed of a combination of chemical and physico-chemical processes including combustion and thermal steps, followed by grinding, powder dispersion by acidic passivation, stabilization of particle dispersions with citrate ligands and embedding of yttrium aluminium garnet (YAG) particles into $$\hbox {SiO}_{2}$$ shells using a seeded growth process before drying. The initial state of the obtained powder is composed of 35 nm crystallites, sintered and agglomerated. The grinding step breaks the sintered bridge, while the passivation and citrate adsorption steps separate the particles by electrostatic repulsion before the silica coating. The optical characterizations are performed and compared separately for the powdered samples that represent the initial and final states of our process, and the dispersion sample represents the intermediate state of our process. The optical measurement revealed an important amount of optical defects at the surface of the particles, compared with micrometric commercial particles. The grinding, nitric acid and citrate steps remove some of these defects. The final state of the sample still possesses lower quantum efficiency than that of a micrometric sample, but the $$\hbox {SiO}_{2}$$ coating allows for a perfect separation of the particle, suitable for implementation in small devices.

Impact of the cationic homogeneity on Th0.5U0.5O2 densification and chemical durability

In order to study the effects of cationic homogeneity on the life cycle of Th1-xUxO2 ceramics, including sintering and reprocessing (dissolution) steps, five different ways of preparation were set up, going from the most homogenous oxalic co-precipitation to a mechanical mixture of the parent oxides. Dilatometric experiments evidenced a better sintering capability for the most homogenous compounds obtained through wet chemistry methods while dry chemistry routes led to poor density values (between 80 and 90 %TD). However, the introduction of an additional mechanical grinding step prior to the powders sintering systematically led to the homogenization of the systems. Improved homogeneity also provide a better chemical durability associated with the congruent release of thorium and uranium in solution during dissolution tests of Th0.5U0.5O2 samples. However, heterogeneous samples led to incongruent behaviors that can be lowered by introducing a grinding step before the sintered samples preparation. Since the impact of the cationic homogeneity must be followed carefully during dissolution, in operando observations of evolving solid/solution interface by ESEM were performed. They allowed imaging the preferential dissolution of uranium-enriched zones and confirmed the significant impact over dissolution rate of the presence of chemical heterogeneities at the interface.

Ye’elimite synthesis by chemical routes

Ye’elimite is formed during the production of sulfoaluminate cement. This article presents the synthesis of ye’elimite by different chemical routes: Pechini method (Pech), Organic Steric Entrapment method (OSE) and Self-Propagating Combustion (SPC). 1250 °C for 1 h is the optimal sintering cycle to synthesize ye’elimite, which is lower than the sintering conditions (1300 °C, 3 h) to obtain pure ye’elimite from solid-state reaction using pure oxide raw materials. OSE and SPC methods produce the purest ye’elimite (> 98 wt%). After the heat treatment, the nanosized crystallites (51 to 57 nm) form particles about 3 times larger (136 to 175 nm) which could result from the sintering of the crystallites. The particles form hard agglomerates whose size ranges between 1 to 100 μm. This distribution, which is typical of a ground Portland clinker, is obtained in the present case directly after sintering and without the necessity of a grinding step.