Thermodynamic Analysis and Experimental Test of Primary Al-Si Alloy prepared by Carbothermal Reduction of Bauxite Tailings

摘要

The thermodynamic analysis on the carbothermal reduction of bauxite tailings was carried out. The carbothermal reduction process, effect of Fe_2O_3 addition on the reduction reaction and the composition of products were studied by various methods such as TG/DTA, XRD, XRF, SEM coupled with EDS. It was found that Fe_2O_3 could not only reduce the reaction temperature and the yield of SiC, but also improve the reduction ratio of Al_2O_3. The proper temperature was 1900°C in the carbothermal reduction of bauxite tailings. The carbothermal reduction process could be divided into 4 stages, and the key stage was the formation and decomposition of carbides stage. Besides Al-Si, Al-Si-Fe phases, there were residual carbides phases in the products.