An Influence of EAF Dust Calcining Conditions on Zinc Leaching Efficiency in Ammonium-Chloride Media

Abstract

An ammonium leaching of electric arc furnace dust (EAFD) was described in this paper. Ural steelmaking plants obtain EAFD of the following chemical composition, %: 23 Zn; 26 Fe; 10 Cl; 2,5 Ca; 2 Mg; 1,2 Pb; 1 Na. The most complete zinc extraction can be achieved with two-stages treatment by calcination of dusts [1], followed by leaching. The effect of calcination temperature (500-1000 °C), calcination time (1-4 hours) and Ca/Fe mass ratio on zinc extraction efficiency in ammonia solutions was studied. The optimal conditions were proposed to extract up to 87% zinc.