Abstract:Iron is one of the main impurity elements in metal zinc products, and it is also a technical problem that needs to be solved urgently in zinc smelting production process. Many studies have been carried out on how to remove iron in zinc hydrometallurgy. In this paper, several zinc hydrometallurgy processes and iron removal methods used in industry were introduced, and the characteristics of iron removal technologies of jarosite process, goethite process, hematite process and oxygen pressure leaching process were analyzed,as well as the product indexes of the corresponding processes, and the iron removal process of zinc neutral leaching residue by pressure reductive acid leaching was studied. The results showed that the iron could be precipitated in the form of hematite slag under the condition of high temperature and high pressure, and the purpose of zinc leaching and iron removal could be achieved without a separate iron removal process, the iron content in the acid leaching solution could be lower than 4 g/L, and the acidity of H2SO4 was 40~50 g/L. The SO2 flue gas produced by the fluidized roaster was used as a reducing agent to be introduced into the front section of the autoclave to reduce Fe3+ in the solution to Fe2+ and the reduction rate of Fe3+ was as high as 94%. O2 was introduced into the middle section of the autoclave to carry out pressure acid leaching on the zinc neutral leaching residue, and the reduction leaching rate of zinc could be as high as 90%. The process could effectively solve the following problems: such as long iron removal process, more equipment, large investment, complex operation etc., and achieve the production purposes of short flow, simplified equipment, convenient operation, high efficiency and safety.