High-indium-zinc Concentrate Non-alumina Slag To Mention Zinc Indium And Iron Removal Technology Test

Zinc concentrate ore obtained from zinc hydrometallurgical process system in Guangxi Laibin Smelter of Huaxi Group Company contains a great of sulphur, iron and indium. Currently, thermal acid leaching jarosite method is commonly adopted. After nearly ten years of production practice, it shows that the production process owns some disadvantages such as long flow sheet, low recovery of indium, high production cost, large quantity of alum slag, difficulty in acid making with sulfur dioxide volatilizing from the process of extracting indium in alum slag. To resolve the above shortcomings, different experiments in connection with zinc leaching and indium extraction were carried out by many research institutes, such as thermal acid leaching-goethite reduction method, thermal acid leaching-EZ method, thermocompression acid selective leaching process and thermal acid leaching-hematite reduction method studied by Beijing General Research Institute of Ming and Metallurgy. Compare to the respective experimental methods, the results show that thermal acid leaching-hematite reduction method successfully solves the existing problem of environmental pollution by volatilization of sulfur dioxide from alum slag. Meanwhile, the recovery of zinc and indium is higher than that of thermal acid leaching-jarosite method, especially the enhanced extent of the recovery of indium is improved by more than 15% and iron in the zinc concentrate ore can be transformed into the hematite for use. The thermal acid leaching-hematite reduction method has certain advantages of technology, but the process also exists shortcomings, such as longer flow sheet, high temperature of 95℃in the processes of thermal acid leaching and reduction, and large steam consumption. Based on the technical achievements of the full use of thermal acid leaching-hematite reduction method test research and the maintenance of the advanced technology, and grounded on the similar conditions of the thermal acid leaching and reduction which high temperature of 95℃and normal atmosphere are requested, in order to simplify the process, high acid leaching and the reduction of low acid leachate are merged into one process, namely the thermal acid reduction leaching of neutral leaching residue.The key of thermal acid reduction leaching technology of neutral leaching residue is the separation of Fe and Zn and effective enrichment of indium. This paper took the theoretical analysis and experimental research to validate the feasibility of the technology of thermal acid leaching-zinc concentrate reduction-neutralization and indium precipitation-iron removal with hematite. The results show that the total recovery of indium, zinc and iron in the whole process reaches more than 95%,87% and 88% respectively. It increases the recovery of indium and zinc, and zinc hydrometallurgy without iron residue is achieved. The technology has strong creativity and environmental benign. And the efficient separation of indium and iron in metallurgical process of zinc and efficient comprehensive utilization of the iron resources are realized. Therefore, a feasible experimental research technology for Laibin Smelter is provided to improve the zinc leaching technology.