Separation of Zinc from High Iron-Bearing Zinc Calcines by Reductive Roasting and Leaching

Abstract

This paper focuses on the selective leaching of zinc from high iron-bearing zinc calcines. The FactSage 6.2 program was used for the thermodynamic analysis of the selective reduction and leaching, and the samples reduced by carbon and carbon monoxide were subjected to acid leaching for the separation of zinc from iron. It is shown that the generation of ferrous oxide should be avoided by modifying V CO (P CO /(P CO + P CO 2 )) in the roasting process prior to the selective leaching of zinc. Gaseous roasting-leaching has a higher efficiency in the separation of zinc from iron than carbothermic reduction-leaching. The conversion of the zinc ferrite in high iron-bearing zinc calcines to zinc oxide and magnetite has been demonstrated by x-ray diffraction (XRD) and magnetic hysteresis loop characterization. This gaseous roast-leach process is technically feasible to separate zinc from iron without an iron precipitation process.

Preparation of Zinc Oxide and Zinc Ferrite from Zinc Hypoxide by Wet Process and Electrochemistry

“…Therefore, in the process of studying zinc oxide, it is necessary to adjust and change the experimental program according to the actual analysis results and to carry out targeted treatment. According to the different leaching agents, the treatment process of zinc hypoxide is usually divided into acid leaching method [1,2], alkaline leaching method [3,4], and ammonia leaching method [5][6][7]. In the ammonia leaching process, zinc oxide exists in the form of zinc-ammonia complexes, and elements such as lead, cadmium, copper and ammonia will also enter the ammonia leaching solution in the form of complexes with ammonia.…”