Alloy Production Through Covalorization of Manganese Sludge and Aluminum Dross

Sludge from wet scrubbing of off-gases from Mn alloy production in the SAF is a largely untapped source of manganese. This study investigates the technical feasibility of using aluminum-based materials to valorize this manganese-rich sludge into a high-quality alloy. Laboratory-scale aluminothermic reduction experiments were conducted in an induction furnace at 1600–1650°C. The sludge was reduced using three different aluminum sources: aluminum scrap and two industrial dross fractions (1.25–5 mm and 5–10 mm). The resulting metal and slag phases were characterized by EPMA (WDS/EDS) and compared with thermodynamic equilibrium simulations from FactSage 8.4. The experiments successfully produced a consistent, low-phosphorus Mn-Si-Fe alloy containing 70–75% Mn. Mass and energy balances of the proposed process indicate that significant amounts of waste can be processed while keeping the requirement for electrical power low (2330 kWh per ton of metal). These findings indicate that aluminothermic reduction is a potentially viable, flexible, and economically feasible process for converting industrial wastes into valuable alloys.