Synthesis of MgSiO3 ceramics using natural desert sand as SiO2 source

Abstract

Abstract High-quality inorganic minerals are being increasingly consumed in the fabrication of ceramics. In the present work, desert sand was adopted as the source of SiO2 to synthesize MgSiO3 and MgSiO3 SiC composite ceramics in an endeavor to economize on mineral resources and improve the desert ecosystem through the industrial application of desert sand. Experimental results show that the use of drift sand enabled the formation of glass phase at lower temperatures, which promoted protoenstatite transformation, prevented sintering cracking, and densified the ceramic bodies. The composites consisted of MgSiO3 (protoenstatite), SiC, glass phase, and small amounts of forsterite and SiO2. The addition of SiC particles caused the green bodies to resist densification, but this was improved by increasing the sintering temperature. The composite ceramic containing 30 wt % of SiC and sintered at 1350 °C had the highest bending strength, whereas that containing 50 wt% of SiC and sintered at 1400 °C had the highest hardness and the lowest coefficient of thermal expansion among all the samples.