Effect of Carbonization Temperature of Rice Husk Char Preparation on SiC Structure and Composition of By-Products in SiC Synthesis with Magnesiothermic Reduction Method

The structure of rice husk char is one of the factors that influence the morphology of SiC and the composition of by-products in the magnesiothermic reduction. This structure can be improved by carbonization. Therefore, this study aims to examine the effect of the carbonization temperature of rice husk char on the structure of SiC and identify the by-products formed by the magnesiothermic reduction. The rice husk char was made by carbonization at various temperatures of 700, 800, 900, and 1000 °C. They were converted to SiC by magnesiothermic reduction at 600 °C, washing with hydrochloric acid, calcination at 700 °C in an air atmosphere, and washing with a mixture of hydrofluoric acid and acetic acid. The products were characterized by FT-IR, XRD, and SEM-EDS. The results showed that creating SiC using the magnesiothermic method with carbonization at a temperature of 1000 °C produced a polytype 2H-SiC, and the by-products were MgO, Mg2SiO4, and Si. MgO was successfully separated in the washing step with a hydrochloric acid solution, while Mg2SiO4 was separated from SiC by washing using a mixture of hydrofluoric acid and acetic acid.