Oxysulfide electrolyte removes impurities from molten steel

Developed by a team at the University of Toronto, the method introduces an oxysulfide electrolyte for electrorefining as an alternative way of removing copper and carbon impurities from molten steel. The process also generates liquid iron and sulphur as by-products.  

The method is described in Resources, Conservation & Recycling and is co-authored by Jaesuk (Jay) Paeng, William Judge and Professor Gisele Azimi.

In a statement, Azimi said: “Our study is the first reported instance of electrochemically removing copper from steel and reducing impurities to below alloy level.”

Currently, 25 per cent of steel is produced from recycled material, but the global demand for greener steel is projected to grow as governments endeavour to achieve net-zero targets.   

Steel is created by reacting iron ore with coke as the source of carbon and blowing oxygen through the metal produced. Current standard processes generate nearly two tonnes of carbon dioxide per tonne of steel produced, making steel production one of the highest contributors to carbon emissions in the manufacturing sector.