The recovery of zinc from EAFD wastes by hydrometallurgy process

Abstract

In this study, we tried to selectively recover zinc from electric arc furnace dusts(EAFD) through hydrometallurgy and produce zinc oxide. The metal content of EAFD was 22% Zn, 10% Fe, 19% Mn, and 0.9% Pb. 85% of zinc and manganese were leached from EAFD through leaching experiment in 1.6M sulfuric acid, 20% solid-liquid ratio, 60℃ for 1 hour. At this time, the pH of the leachate was 5.8, and Fe was not leached. A solvent extraction process was used to recover Zn from Mn in the leachate, and D2EHPA was selected as an extractant. 99% Zn was extracted through 32% saponified 0.8M D2EHPA, O/A ratio 2, and 3 stage counter-current extraction. Zn was stripped from loaded organic at an O/A ratio of 4 using 1.5M sulfuric acid, followed by ZnSO₄ powder was obtained through a vacuum distillation process. Finally ZnO powder was manufactured from the obtained ZnSO₄ by calcining at 800℃.