Technological Options for Comprehensive Processing of Manganese Ferroalloy Production Dust Containing Non-Ferrous Metals

Abstract

During the production of ferromanganese and ferrosilicomanganese alloys, large amounts of dust containing manganese and valuable non-ferrous metals such as zinc and lead are generated. Efficient utilization of this dust is essential for resource recovery and environmental protection. This study investigates processing approaches for zinc- and lead-rich and zinc- and lead-poor dusts formed during manganese ferroalloy smelting at the Taraz Metallurgical Plant (Kazakhstan). Laboratory and semi-industrial experiments were performed using electric smelting and Waelz processing of briquetted dust with carbonaceous reducing agents. Thermodynamic modeling with the HSC-6 software was applied to determine equilibrium conditions and metal distribution. Smelting of lead-rich dust (28.6% PbO) yielded crude lead (92–95% Pb), lead–zinc sublimates (15–26% Zn, 6–17% Pb), and manganese-rich slag (45–46% MnO). Waelz processing of zinc-rich dust (31.1% ZnO) produced sublimates with 53–55% Zn and 6–7% Pb, and clinker with 38–41% MnO. Metal recoveries reached 84–98% Zn, 91–97% Pb, and 82–99% Mn. The developed technological schemes ensure efficient, environmentally safe recovery of metals and complete utilization of ferroalloy production residues.