Extraction of Critical Electronic Materials from Steelmaking Wastes

The stable domestic supply of gallium, indium, and germanium has been identified as a critical need for the USA. Electric arc furnace dusts processed to recover zinc produce a process residue that could be a potential source of these critical materials. An industrial zinc leach residue was characterized to determine the predominant mineral phases and leached with common mineral acids. Atmospheric agitated leaching using sulfuric acid and hydrochloric acid were examined to determine the extractions of gallium, indium, and germanium as a function of concentration, temperature, and time. Extractions of gallium were found to be similar to iron in all experiments. The maximum percentage of Ga, Ge, and In leached into solution were 82%, similar to 100%, and 89%, respectively.

Automated summary

The stable domestic supply of gallium, indium, and germanium is crucial for the USA. Process residue from the recovery of zinc from electric arc furnace dusts could potentially serve as a source of these critical materials. An analysis of an industrial zinc leach residue revealed the main mineral phases, and leaching experiments with sulfuric acid and hydrochloric acid were conducted to determine the extractions of gallium, indium, and germanium under varying conditions. The extraction of gallium was found to be similar to that of iron in all experiments, with maximum leaching percentages of 82% for Ga, close to 100% for Ge, and 89% for In.