Mullite fabrication from natural kaolin and aluminium slag

Chargui, Fouzia; Hamidouche, M.; Belhouchet, H.; Jorand, Yves; Doufnoune, Rachida; Fantozzi, Gilbert

doi:10.1016/j.bsecv.2018.01.001

Cited by 66 publications

(41 citation statements)

References 25 publications

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“…Results of the X-ray diffraction measurements displayed in Figure 1 show that all samples contain the same alpha alumina phase [15,16]. Since no changes in the X-ray diffraction pattern are noticeable, one can assume that Cr 2 O 3 at the studied concentrations does not cause any major disruptions in the crystalline lattice of the host matrix.…”

Section: Xrd Measurementsmentioning

confidence: 99%

Usability of Cr-Doped Alumina in Dosimetry

et al. 2019

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Dosimetry is a widespread material science field dealing with detection and quantification of ionizing radiation using electronic processes in materials. One of the main aspects that determines the performance of dosimeters is the type of defects the material contains. Crystalline lattice imperfections are formed around impurity ions, which may have a smaller or larger size, or different oxidation states compared to host ions. In this study, we show what effects Cr impurities have on the luminescent properties of alumina. Porous Al 2 O 3 : Cr microceramics synthesized using the sol-gel method showed a higher thermoluminescence response than a single crystal ruby. We have found that Cr 2 O 3 concentration of 0.2 wt% was optimal; it yielded the highest X-ray luminescence and thermostimulated luminescence readout of all studied additive concentrations added to alumina during synthesis. Our results show that Cr doped alumina could potentially be used as a promising new material for dosimetry of ionizing radiation.

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Section: Xrd Measurementsmentioning

confidence: 99%

Usability of Cr-Doped Alumina in Dosimetry

et al. 2019

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“…Goski and Caley [12] investigated the reaction sintering of kyanite and alumina to form mullite composites, and the resulting 78%-22% mullite material formed a finegrained structure (1 μm) with 14% decrease in shrinkage and 11% reduction in linear expansion coefficient. Chargui et al [13] prepared mullite from natural kaolin and aluminum slag; they studied the structural transformations of kaolinaluminum slag mixtures during heating. e amount of formed mullite increases with the firing temperature; at 1500°C, the mullitization of the mixture is almost complete.…”

Section: Introductionmentioning

confidence: 99%

Effect of Particle Size and Sintering Temperature on the Formation of Mullite from Kyanite and Aluminum Mixtures

Hernández

Labra

Guerrero

et al. 2021

Advances in Materials Science and Engineering

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The effect of particle size and sintering temperature of the mixtures of kyanite and metallic aluminum related to the thermal transformation of kyanite into primary mullite and free silica was studied. In addition, the reaction between α-Al2O3 (in situ produced by aluminum oxidation) and the silica was obtained in cristobalite structure from kyanite to obtain secondary mullite. The kyanite powders were milled by 0.5, 3, 6, and 12 hours and then were mixed with aluminum powder, which were previously milled by 3 hours. After that, the powders were characterized by X-ray diffraction technique (XRD), scanning electronic microscopy (SEM), differential thermal analysis (DTA), and thermogravimetric analysis (TGA), and the particle size was determined in a centrifugal analyzer particle size Shimadzu model SA-CP4. The mixed powders were pressed uniaxially into cylindrical samples (compacts), and then sintering was conducted at 1100, 1200, 1300, 1400, 1500, and 1600°C; these samples were characterized by XRD, SEM, and thermodilatometry analysis (TD); density and open porosity measurements were performed by the Archimedes method. The samples were thermally etched to observe the microstructure, which consisted of mullite equiaxial grains contained in a glassy phase. It was observed that the nonmilled kyanite mineral becomes into mullite plus silica at temperatures between 1400 and 1500°C. When the particle size was reduced at sizes less than 1 µm, the transformation temperature was low until 200°C; the X-ray patterns of the sintered samples at 1400°C, ground for 6 hours, showed mullite peaks with small reflections of cristobalite and α-Al2O3, and these samples exhibited high density and low open porosity.

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“…Compositions containing kaolin residue were analyzed 19 and mixed with sericite clay, industrial kaolin and alumina to synthesize mullite and concluded that kaolin residue and sericite were very useful raw materials for the preparation of mullite. Mullite was produced from natural kaolin and aluminum slag, 20 the amount of mullite formed increased to higher firing temperatures. Compositions containing clay and different residues (rich in silica and alumina) as raw materials for the manufacture of insulation refractories were evaluated, 21 the samples showed low thermal conductivity, high porosity, low density, high electrical resistivity, and moderate resistance to bending, suggesting that they can potentially be used for the application desired.…”

Section: Introductionmentioning

confidence: 99%

Development of cordierite/mullite composites using industrial wastes

Brito

Almeida

Neves

et al. 2020

Int J Applied Ceramic Tech

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1 | INTRODUCTION Cordierite (2MgO•2Al 2 O 3 •5SiO 2) is one of the most important phases of the MgO-SiO 2-Al 2 O 3 system, having a low coefficient of thermal expansion, excellent thermal shock resistance, low dielectric constant, high resistivity, high chemical resistance, high refractoriness, and high mechanical strength. 1-7 Cordierite-based materials are used in various industrial fields in applications such as refractories, heat insulation, filters, membranes, heating elements, microwave and electromagnetic wave absorbers. 8 There are various methods used to synthesize cordierite, among which solid-state reaction, sol-gel, and glass crystallization stand out. 9 Cordierite synthesis by solid-state reaction is considered to be the most widely used in industry due to its simplicity and low cost. 10 Regarding the formation of cordierite by solid-state reaction, some researchers 11 described this reaction as occurring through two well-defined steps. In the first step, cordierite begins to form at 1100°C, between mullite, enstatite, and cristobalite, and reaches a peak at 1275°C. In the second stage, previously formed cordierite reacts through a differential fusion mechanism with enstatite and cristobalite, forming a liquid at around 1330°C to 1355°C. This liquid is made up of eutectic cordierite-enstatite-silica. With increasing temperature, the liquid begins to react with the remaining

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Mullite fabrication from natural kaolin and aluminium slag

Cited by 66 publications

References 25 publications

Usability of Cr-Doped Alumina in Dosimetry

Usability of Cr-Doped Alumina in Dosimetry

Effect of Particle Size and Sintering Temperature on the Formation of Mullite from Kyanite and Aluminum Mixtures

Development of cordierite/mullite composites using industrial wastes

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