Investigation of some physical properties of SiC produced from waste materials by mechanical activation reduction method

Silicon carbide (SiC) is used in armor production together with boron carbide (B4C) in advanced technology materials, in the aviation and space sectors due to its high heat resistance and wear resistance, and its use as a semiconductor in the electronics world, as an alternative to silicon, is increasing. For this reason, SiC production is becoming quite important. Although silicon carbide production is carried out with certain methods, in this study, the selection of raw materials used in SiC production from waste and the application of intensive milling processes and the production of SiC at lower temperatures and in shorter times have made the study quite important. Although the produced product is available in the literature, the raw material and reducer used are not available in the literature. In the Acheson Process used in SiC production today, high purity silica and is used as raw material and petroleum coke is used as reducer. In this study, two different silica (SiO2) powders were used as raw materials. Experiments were first conducted with commercial SiO2, and SiC was produced by optimizing experimental conditions. Later, as part of the ERA-MIN3 2021 project Work Package 6 (IP6), precipitated amorphous SiO2 powder, obtained with a purity of 97.7% following alkaline leaching processes, was used to produce SiO2 powder, which is the residue formed after acid leaching of silicate minerals. Biochars produced from almond shells in our own laboratories were used as reducers and sodium silicate was used as binders. First, carbonization processes were applied to almond shells at different times and temperatures and the best carbon ratio was reached in the biochar obtained by processing ground almond shells at 700 ℃ for 4 hours (carbon ratio 92.83%). The SiO2 and biochar mixture was subjected to intensive milling processes in the planetary mill at different times and speeds and the highest amorphization ratio was obtained by grinding at 400 rpm for 4 hours. The products obtained in milling were subjected to reduction-carburization processes both in the muffle furnace and in the resistance furnace designed and manufactured by us. XRD and other analyses performed after the resistance furnace process showed that SiC was produced. It was determined that the produced SiC had a purity of over 98%.