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The capability to fabricate ultra-low and customizable CTE materials with good mechanical properties in a simple method was demonstrated in this work. For this purpose, nano beta-eucryptite and alumina powders were synthesized and used in the composite's fabrication. Four composites of alumina and a second-phase beta-eucryptite were prepared, containing 10, 20, 30, and 40 wt.% beta-eucryptite. The temperature effect on prepared composites is investigated. The results of XRD analysis and the microstructures of prepared composites are discussed with results of mechanical strength and thermal expansion at temperature ranges of 1400, 1500, and 1550 °C. The CTE of alumina-beta-eucryptite composites decrease as the beta-eucryptite content increases, reaching -1.036 × 10–6 °C−1. The findings show that a composite with a very low thermal expansion coefficient and good mechanical properties can be designed and used in different applications. [ABSTRACT FROM AUTHOR]

The recycling of industrial waste clays for production of an interesting ceramic product is the main goal of the present research work. Ceramic bodies were prepared using Feeders or Cyclons waste clays, sand and feldspar. 0.0, 15, 20, and 25 wt.% of sand were added at the expanse of kaolin (75-50 wt.%). Constant mass percent (25 wt.%) of feldspar was added for all ceramic compositions. The designed batches were sintered at 1200–1400 °C. Physical properties were determined by water displacement method. Phase composition and microstructure were investigated by x-ray diffraction and scanning electron microscope, respectively. The compressive strength was also determined. The results indicated that the ceramic bodies prepared from Cyclons' waste clay exhibited higher physical and mechanical properties than that prepared from Feeders' clay after sintering at 1400 °C. The addition of sand enhances the porosity, water absorption, bulk density and mechanical strength after sintering at 1400 °C due to the formation of mullite network and glassy phases. [ABSTRACT FROM AUTHOR]

Organo modified nanoclay (OMNC) and OMNC/sawdust mixture were prepared and applied for hydrocarbon removal from water. Montmorillonite and sawdust were used as raw materials while cetyl trimethyl ammonium bromide (CTAB) used as surfactant. The removed oils were gasoline, diesel and lubricating oil. The sawdust contents in the mixture were 0, 5, 10, 15, 20, 30, 40 and 50 wt.-%. The obtained OMNC and OMNC/sawdust mixture were investigated for their oil removal characteristics by foster swelling test, adsorption capacity, hydrocarbon-water separation test and remaining hydrocarbon determination. The results revealed that the OMNC adsorbed gasoline and diesel 3 times more than its weight and about 2 times for lub.oil and the adsorption increased with increasing surfactant loading. For the mixtures containing 5, 10, 15 and 20% sawdust, improvement in adsorption capacity and coagulation efficiency were detected as compared with those of OMNC alone. The sawdust in the mixtures was functioned as a fibrous framework for combination of coagulated oil and OMNC. This facilitated the floating as well as aggregate formation and subsequently removing of hydrocarbon aggregates. On the other hand, when the sawdust content exceeded 20%, deterioration in adsorption capacity and coagulation efficiency of hydrocarbon was obtained. The total hydrocarbon removal percentage was reached as high as 97.32% and the purified water was totally free from hydrocarbon. [ABSTRACT FROM AUTHOR]

The present work depends on recycling of fly ash by preparation of stoichiometric mullite containing various amounts of Co3O4; 0, 5, 10, 15 wt.% to obtain pigment ceramic materials. The mixtures were sintered at different temperatures; 1250, 1350, 1400, 1450, 1500 and 1550 ∘C to follow the phase compositions, structure, physical, mechanical, electrical, magnetic properties and the color behaviors. The results indicate that the sintering at 1250 ∘C is the optimum condition for the formation of the blue pigment ceramic materials. The sintering from 1250 to 1500 ∘C shows increase in the bulk density and the strength properties up to 15 wt.% Co3O4. The incorporation of cobalt (II, III) oxide into the mullite system enhances the electrical and magnetic properties to be used as ferromagnetic materials. [ABSTRACT FROM AUTHOR]