Abstract
Black shale vanadium-bearing quartzites are predominantly processed by sulfuric acid leaching with the recovery of vanadium, molybdenum, uranium, and rare earth elements, resulting in the formation of vanadium-bearing shale leaching residue. Currently, cake of leaching vanadium black shale quartzite is mainly utilized in the construction industry for the production of building materials with low added value. This study investigates the production of ferrosilicon from a mixture of autoclave leaching residue of vanadium-bearing black shale quartzites and long-flame coal beneficiation tailings. The experiments were conducted using a second-order rotatable experimental design combined with electric smelting in an electric arc furnace to determine the optimal technological parameters. The results demonstrate that ferrosilicon grades FeSi45 and FeSi50 can be obtained from leaching residue and coal beneficiation tailings depending on their ratio and the proportion of steel shavings added to the charge. The optimal parameters for producing FeSi45 with a silicon recovery of 75.0-80.1% are a tailings-to- leaching residue ratio of 1.42:1-1.7:1 and 16.7-23.05% steel shavings. For FeSi50 with a silicon recovery of 75.0-79.4%, the optimal ratio is γ=1.44:1-1.7:1 with 14.3-17.8% steel shavings. Pilot-scale laboratory electric smelting of a charge containing 51.3% coal beneficiation waste, 30% leaching residue, and 18.7% steel shavings confirmed the feasibility of producing FeSi45 with a silicon content of 41.1-43.4% and a silicon recovery of 79% in the alloy.