Effects of Phenol Addition on Oil Extraction from Moroccan Oil Shale by Supercritical Toluene

In the present work, the effect of phenol on the supercritical extraction of the organic matter from Tarfaya's oil shale with toluene was evaluated. The experimental results showed clearly that phenol had a significant effect on the yield and the composition of the oils obtained. Moreover, it was shown that phenol was a very efficient modifier for oil shale, giving a good yield of recovery and a suitable maturation of the organic matter. The pitches prepared by mixing phenol and toluene contain more aromatics and have a high char yield at 950 °C compared to those obtained by extraction with supercritical toluene alone

Temperature behaviour of structural, dielectric and piezoelectric properties of sol-gel processed ceramics of the system LiNbO3-NaNbO3

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Effet du dopage par le fer sur la synthèse de la ye’elimite

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Role of dispersant and humidity on the setting of millimetric films of aluminous cement prepared by tape casting

International audienceAn aluminous cement (Secar 71 from Lafarge) has been used for preparing millimetre thick films by tape casting. Slurry preparation is described. The effect of several dispersants has been studied. The optimum dispersion, associated with the minimum viscosity, is obtained with minimal amounts of dispersant in the case of acetic and propionic acids. Indeed, the corresponding quantities of dispersant are less than 0.5% by weight relative to cement. In addition to its dispersive role, acetic acid plays a role in the setting. It has a retarding effect below 1% by weight relative to the mass of cement and from this amount, it plays an accelerating role on setting. Tapes prepared with cement, water, acetic acid, PEG 300 have been left to set in different environments at 20 °C (50% or 95% relative humidity, water). The formation of aluminous calcium hydrates is most important when setting is done in water. Lastly, the advantage of setting in water is also discussed with respect to the elimination of the different organic products that have been used for tape castin

Etude à l’aide du modèle Kubleka-Munk de l’opacification d’un verre boro-calcique par des phosphates

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Thermal and mechanical properties of cordierite refractory ceramic produced from stevensite-rich clay, kaolin and alumina

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Study of borosilicate glaze opacification by phosphates using Kubelka-Munk model

International audienceThe aim of this work was to study the effects of additions of sodium metaphospahte (1–50 Wt.%) on optical properties of a conventional borosilicate glaze.The optical properties were evaluated by diffuse reflectance measurements. The absorption and the scattering properties of the obtained glazes, were explained through the Kubelka-Munk model. The structural and microstructural properties were determined by X-ray diffraction and Scanning Electron Microscopy. It was shown that white opaque borosilicate glazes can be obtained for an addition of 5 Wt% to 50 Wt% of sodium metaphosphate and 20 Wt% seemed the optimum amount to obtain a perfect white opacity. The opacification process is based on the light scattering phenomenon wherein the nature of the scattering centers vary depending on the amount of sodium metaphosphate addition. In the case of 20 Wt% scattering centers have been identified as Ca10(PO4)6O and NaCa(PO4) crystals formed by a devitrification process

Influence of sintering temperature on the mechanical properties of cordierite synthesized from andalusite and talc

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