Work

Green production of Fe–Cr–Cu master alloys via electric smelting of pre-reduced briquettes prepared from copper slag and chromite

Year: 2025

Type: article

Abstract: Copper slag not only exacerbates environmental risks associated with heavy metals due to its annual accumulation in the tens of millions of tons but also highlights the deep-rooted challenges faced by industrial civilization in the context of resource recycling systems. This study presents a green process for producing Fe-Cr-Cu master alloys through the electric smelting of pre-reduced briquettes made from copper slag and chromite. Thermodynamic analysis, a multi-parameter coupled optimization experimental system, was used to systematically explore the migration behaviours of metal elements and slag phase regulation mechanisms in the smelting process. The results indicate that with a smelting temperature of 1600°C, a duration of 80 minutes for smelting, a briquet basicity of 0.6, and a coke ratio of 6 wt.%, the recoveries for Fe, Cr, and Cu were recorded at 98.93%, 96.23%, and 95.56%, respectively. The produced Fe-Cr-Cu master alloys with 74.98 wt.% Fe, 17.01 wt.% Cr, and 1.23 wt.% Cu was achieved. Alloy inclusions within the slag phase were measured to be less than 0.5 μm in size, exhibiting a distribution density of roughly 1 per/mm 2 . This study proposes a viable “waste as a substitute for ore” strategy for the valorization of copper slag, offering a practical solution to the critical issues of resource depletion and pollution. Moreover, the developed Fe-Cr-Cu alloys serve as a high-quality burden for copper-containing special steels, which can shorten its flowsheet of production and save energy consumption.

Source: Journal of Materials Research and Technology

DOI: 10.1016/j.jmrt.2025.06.116