Novel Technology Study On Treatment Of High Iron Zinc Calcine By Mineral Processing And Metallurgy Method

In order to effectively recover zinc and iron from high iron bearing zinc sulfide concentrates, avoid high environmental risk as the discharge of hazardous iron residue and simplify the existing process of zinc production, a novel method to dispose of high iron bearing zinc calcine by "magnetization roasting, leaching and magnetic separation" or "magnetization roasting, magnetic separation and leaching" route was proposed and investigated in this paper. Some valuable results were obtained as follows.The zinc ferrite (ZnFe2O4) in the zinc calcine was selectively decomposed to zinc oxide and magnetite after magnetization roasting, which is beneficial to zinc extraction by low acid leaching and iron recovery by magnetic separation. The extraction of zinc increased from80.27%(raw sample) to90.22%after the magnetization roasting using CO, and it could reach92%by the roasting under coal gas atmosphere. In the mean time, iron extraction was enhanced to about10%from approximately2%, which could be controlled as5%with more than90%of zinc leached out if two-stage leaching technology was adopted. In the magnetization roasting step, a certain amount of ZnFe2O4had not been decomposed due to the enclosure by other minerals, while some ZnS had been formed for the existence of S, and both were reported into residue during the subsequent leaching process.Due to the complexity of raw material caused by the dissemination of different fine grains, it is obvious that physical separation method would not be capable of realizing the liberation of magnetite grains, therefore the separation of zinc and iron is hardly achieved by "magnetization roasting, magnetic separation and leaching" process. By contrast, most of iron as magnetite could be separated and remained in the leaching residue by "magnetism roasting-leaching-magnetic separation" process, the results showing that iron content was concentrated to53.24%with84.32%recovery after magnetic separation consisting of one roughing and one cleaning was conducted for the residue. The product with high iron samples can be used as a raw material for steelmaking.The present study developed a new green technology for treatment of high iron bearing zinc calcine by the method of mineral processing and metallurgy, which can successfully achieve the separation and recovery from zinc ferrite. The established technology is of great importance for the utilization of high iron bearing sphalerite that is abundant in our country.