Optimal parameters for obtaining ferrosilicon from a mixture of amorphous silica-containing rocks: Tripoli and flask

Ferrosilicon smelting can be more intensive if its amorphous variety with increased reactive capacity is used instead of crystalline silicon-containing substance. The article presents the results of experimental determination of optimal process parameters for obtaining ferrosilicon from a mixture of tripoli and flask. The studies were carried out by electric smelting using the method of second-order rotary planning with subsequent geometric optimization. The influence of replacing insufficient steel cuttings with magnetite concentrate and FeSi25 ferrosilicon on the process parameters of ferrosilicon smelting was determined. The studies showed that electric smelting of a mixture of tripoli and flask (with a ratio of 1:1) results in the formation of FeSi25, FeSi45 and FeSi50 ferrosilicon. The optimal parameters for obtaining FeSi25 ferrosilicon with 90.37-92.61% Si extraction are 42.7-44% coke, 34.4-35% cuttings; FeSi45 with 75.0-78.66% Si extraction - 39.2-44% coke, 28.75-31.4% cuttings; FeSi50 with 7073.43% Si extraction - 40.1-44% coke, 25.5-28.9% cuttings. Replacing 20% of steel cuttings with magnetite concentrate leads to the formation of FeSi50 ferrosilicon (Si content 48%) with an increase in silicon extraction into the alloy to 76.8%. Replacing 60% of steel cuttings with FeSi25 ferrosilicon allowed to obtain FeSi50 ferrosilicon and increase silicon extraction to 86.8%. At that, in comparison with obtaining a ferroalloy from quartzite, the degree of silicon extraction into the alloy and the concentration of silicon in it significantly increase.