Electrorefining for copper tramp element removal from molten iron for green steelmaking

Abstract

Steel recycling is crucial for lowering greenhouse gas emissions and reducing the pressure on natural resources within the manufacturing sector. Yet, the challenge of effectively dealing with impurities like carbon and tramp elements (copper), in scrap materials, persists as a major obstacle that current technologies fail to fully overcome. This study introduces an innovative oxysulfide electrolyte for electrorefining that significantly enhances steel recycling by effectively removing carbon and copper impurities from molten iron. This method not only achieves simultaneous extraction of these elements but also generates liquid iron and sulfur as by-products. By applying an electromotive force, this approach propels non-spontaneous electrochemical reactions, achieving refining efficiencies surpassing traditional methods. Results indicate a substantial reduction in carbon levels and copper to as low as 790 ppmw from 0.43 wt% Cu from molten iron can be achieved. The electrorefining process using this electrolyte offers a promising solution for improving scrap recycling in secondary steel production, highlighting its potential for reducing emissions and overcoming current technological limitations.