A method for recovering zinc and iron in zinc oxygen pressure leaching slag

Abstract

The invention provides a method for recycling zinc and iron in zinc oxygen pressure leaching slag. The method comprises the following steps that ingredient preparation is conducted according to mass ratio of zinc oxygen pressure leaching slag: concentrated sulfuric acid: bisulfate being 1: 0.4-2: 0.1-2; the ingredients are uniformly mixed, and roasting is conducted at 200-40 DEG C and lasts for 0.5-5 hours to obtain a roasted product; the roasted product is subjected to sulfuric acid solution leaching at 20-95 DEG C, concentration of the sulfuric acid solution is less than 5 wt%, and the leaching time is 0.5-4 hours; filtering is conducted, zinc and iron are placed into filter liquor I containing zinc and iron, iron powder is added into the filter liquor I containing zinc and iron, the Fe<3+> is restored to Fe<2+>, and filtering is conducted to obtain filter liquor II containing zinc and iron; and the filter liquor II containing zinc and iron is subjected to zinc extraction, and therefore zinc can be recycled. The rest liquor containing iron is subjected to evaporation, refrigeration and crystallization, and therefore byproduct ferrous sulfate heptahydrate crystal can be obtained.The zinc and iron in zinc oxygen pressure leaching slag can be efficiently extracted. The recycling rate of the zinc is greater than 96%, and the recycling rate of the iron is greater than 95%. The method has the advantages that recycling rate is high, operation is convenient, and energy consumption is low.

Description

technical field The invention belongs to the field of nonferrous metal smelting, and relates to a method for recovering valuable metals, in particular to a method for recovering zinc and iron in zinc oxygen pressure leaching slag. Background technique A large amount of zinc oxygen pressure leaching slag will be produced in the zinc oxygen pressure leaching process of zinc concentrate, and these slags still contain a certain amount of valuable metals, such as Zn content is 4-10%; Fe content is 15-30%. Apart from stockpiling, there is currently no suitable way to deal with it. As the country's requirements for environmental protection are getting higher and higher, the high-value utilization of zinc oxygen pressure leaching residue has become an important topic in the field of environmental protection and secondary resource utilization. It has high economic value and potential social benefits. . Generally speaking, the recovery methods of zinc and iron in zinc oxygen pressu...

AI Technical Summary

Problems solved by technology

Due to the large differences in the properties of zinc oxygen pressure leaching slag, and the complex content and types of impurities, there is no fixed process route for its treatment

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