Smelting silicon metal operation guide
The process of smelting silicon metal is a slag-free process, and the selection of silicon metal smelting for chemical use is more strict, which not only has less impurity content, but also requires high mechanical strength, enough thermal stability and suitable particle size composition. Silica is preferred for smelting metal for chemical use. Silica in its natural form occurs either as a single quartz mineral, or as rocks composed almost entirely of silica-silica, or as sandstone in the form of silica-silica. Impurities and adhesives in silica-containing minerals used in the production of silicon metals for chemical use may be completely reduced or partially reduced during smelting, or may enter the product silicon in the form of compounds or form slag. This not only increases energy consumption, reduces product quality, but also causes difficulties in the smelting process.
Therefore, the chemical composition of silica-containing minerals used in smelting silicon metal for chemical use is strictly required. It is required that SiO2 is greater than 99%, Fe2O3 is less than 0.15%, Al2O3 is not more than 0.2%, CaO is not more than 0.1%, and the sum of impurities is not more than 0.6%. The silica used must be washed before smelting and the surface is clean.
