NOUFERROUS METALLURGICAL EQUIPMENT

The jarosite slag produced in the process of zinc hydrometallurgy is harmful to human health and ecological environment, and will lead to waste of valuable metals. Therefore, it is imperative to treat and recover jarosite slag. Based on analysis of the composition and phase change of the raw jarosite slag, the optimum technological conditions and phase change law of Zn recovery from jarosite slag by melting and fuming based on carbothermal reduction method are discussed under the theoretical guidance of thermodynamic calculation. By calculation, the zinc phase in the jarosite slag is ultimately enriched in the form of zinc oxide (ZnO) in the fume; and the rationality of the theoretical calculation was verified based on the results of orthogonal experimental analysis. Considering reducing energy consumption, the experimental results were finally confirmed, and the optimum conditions for zinc recovery in the melting and fuming process of jarosite slag were as follows: reaction temperature 1200℃, holding time 100min, air flow rate 600mL/min and carbon ratio 30%, under these conditions, the recovery rate of zinc was 99.70%. The study provides a practical reference value for the recovery and utilization of zinc in jarosite slag.