Method for recovering valuable metals by comprehensively treating high-iron and low-germanium zinc oxide calcine and zinc sulfite

Abstract

The invention discloses a method for recovering valuable metals by comprehensively treating high-iron and low-germanium zinc oxide calcine and zinc sulfite. The method comprises the following steps: 1) primary leaching of zinc oxide calcine; 2) secondary leaching of zinc oxide calcine; 3) zinc sulfite analysis and ferric reduction; and 4) tannin germanium precipitation. In the process of recovering valuable metals by comprehensive treatment, the zinc sulfite analysis and the reduction of ferric ions, namely ferric sulfate in a solution into ferrous ions, namely ferrous sulfate are completed at one step by using a simple and convenient method, so that resources are sufficiently recycled, and the production cost is reduced; and the problems that zinc and germanium are recovered by analyzing zinc sulfite into a zinc sulfate solution and the ferric ions in a system for recovering zinc and germanium from the zinc oxide calcine cannot form an open path because of being enriched are simultaneously solved, meanwhile, the filtering performance for liquid-solid separation of the whole production system is also improved to ensure that the solution is clear and has no suspended matters, and consumption of tannic acid can be reduced and the grade of a germanium concentrate can be improved in the tannin germanium precipitation process.

Description

technical field [0001] The invention belongs to the technical field of hydrometallurgy, and in particular relates to a method for comprehensively treating high-iron, low-germanium zinc oxide calcine and zinc sulfite to recover valuable metals. Background technique [0002] In the production process of zinc hydrometallurgy, zinc concentrate is boiled and roasted to produce roasted ore for zinc hydrometallurgy and high-concentration sulfur dioxide flue gas for acid production. After the roasted ore undergoes neutral leaching, the germanium and iron in it are enriched in the leaching slag, and the leaching slag is volatilized by a rotary kiln to recover zinc and other valuable metals, and zinc oxide fumes for defluorination and chlorine are produced and used for production Low concentrations of sulfur dioxide gas from zinc sulfite. If the content of germanium in the raw materials for zinc smelting is too low and the impurity elements such as iron, fluorine, and chlorine are hi...

AI Technical Summary

Problems solved by technology

However, the following problems occurred in production: First, a large amount of iron was leached out during the secondary leaching of zinc oxide calcined sand, and it was almost ferric iron, that is, ferric sulfate. Since the filtrate of the primary leaching needs to undergo tannin precipitation and germanium, the acid pH at the end point is controlled to be 2.0~3.5. Most of the ferric iron is hydrolyzed into ferric hydroxide colloids and precipitates in the slag, making filtration difficult, and enrichment cannot be obtained. Moreover, the ferric iron left in the solution without hydrolysis and precipitation is very unfavorable to the next step of tannin precipitation. It seriously consumes tannic acid and reduces the grade of the produced germanium concentrate. At the same time, the precipitation of germanium is not complete.

Therefore, it is necessary to use reduced iron powder to purify before sinking germanium. The purpose is to reduce the ferric iron in the germanium sinking solution to the ferrous iron that has no effect on tannin sinking germanium; The arsenic in it is easy to form highly toxic arsine gas and release it to cause injury to operators

Second, zinc sulfite is decomposed with dilute sulfuric acid into zinc sulfate slurry and sent to the electrolytic zinc production system as a pre-liquid to recover zinc. The germanium and lead in it are not recovered and are depleted, resulting in a waste of limited resources.

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