Recovery and enrichment of valuable metals from zinc oxide dust and mitigation of toxicity based on tartaric acid and hydrogen peroxide

Abstract

Considering the lack of some valuable metal resources and the toxicity of zinc oxide dust. In this study, firstly, sulfuric acid and tartaric acid were used as solvents to dissolve zinc, germanium, indium, and tin or produce soluble complex dissolution under the action of ultrasonic wave. In addition, the introduction of tartaric acid can not only effectively decompose zinc ferrite, release germanium and indium in its lattice, but also reduce Fe3+ (Ferri ion, Ⅲ) and overcome the defects of Fe3+ hydrolysis-coprecipitation. Then, sulfuric acid and hydrogen peroxide were used to promote the dissolution of metal sulfides, thereby improving the comprehensive recovery rate of metals. The study demonstrates that the final recovery rate of metals was 97.44 %, 97.01 %, 91.26 %, and 90.86 %, respectively, and the slag rate was 30.36 % under optimal conditions. The grade of lead and argentum in the residue were increased to 50.68 % and 691.63 g·t−1. During the reaction, about 50 % of arsenic and 95 % of cadmium entered the solution and were removed. Compared with the enterprise, this process shortens the total leaching time to 90 min, greatly reduces the amount of sulfuric acid, significantly improves the recovery rate of valuable metals, and reduces the toxicity of slag.