NOUFERROUS METALLURGICAL EQUIPMENT

The raffinate of a gold smelter which adopts concentrate roasting and acid leaching for copper extractioncontains a high level of zinc ions. To recover the zinc, a process of pre-neutralization and sulfidization in stages is explored, with ZnS concentrate as the recovery product. The experiment explored the paths and the interplay of each main element through raffinate pre-neutralization, clarification, and sulfidization, and examined the process parameters in each unit operation. According to the experiment results, at room temperature and with sodium sulfate excess rate at 1.3, sulfidization pH=3.0, and precipitation lasting 30min, the Zn recovery from the raffinate reaches 96.56%, and the Zn grade of the precipitation product reaches 52.32%; after pre-neutralization and clarification for As, Cu and other impurities removal, the Zn grade of the sulfurization precipitation product reaches 54.08%.