Method for recovering valuable metals from high-silicon low-germanium and low-indium zinc oxide soot

Abstract

A method for recovering valuable metals from high-silicon low-germanium and low-indium zinc oxide soot includes the steps of (1) primary leaching, (2) secondary leaching, (3) silicon purification and adsorption, (4) indium deposition through neutralization and (5) germanium deposition through tannin. Through the simple and convenient method, purification and removal of silicon and the adsorption performance of amorphous carbon are combined, so that full recycling of resources is achieved. Through the adsorbability of the amorphous carbon, the filtering performance in solid-liquid separation during silicon purification is well improved, an effective carrier is provided for suspended matter in a solution, and therefore filter liquor is clear and free of suspended matter. By means of the method, the influence of silicon and suspended matter on indium and germanium deposition is eliminated, and the effects of burning heat generation and reduction of the added amorphous carbon can be played normally in the volatilization process of a rotary kiln. Under the conditions that the grade of indium and germanium in raw materials is low and the grade of silicon dioxide is high, interference of silicon and suspended matter is avoided, and germanium and indium are smoothly recovered.

Description

technical field [0001] The invention belongs to the field of hydrometallurgy, and in particular relates to a method for recovering valuable metals from high-silicon, low-germanium, and low-indium zinc oxide dust. Background technique [0002] Most of the raw materials used in zinc hydrometallurgy contain a certain amount of germanium and indium, and some are difficult to be recycled because the content is too low. In the production process of zinc hydrometallurgy, most of the germanium and indium are enriched in the leaching slag after neutral leaching of the raw materials, and the leaching slag is volatilized in a rotary kiln to recover zinc, while valuable metals such as germanium, indium, and lead are also volatilized It is enriched in zinc oxide dust; however, the content of germanium and indium in some zinc smelting raw materials is too low, and the content of germanium and indium in the produced zinc oxide dust is not high. The zinc oxide dust produced by our company ...

AI Technical Summary

Problems solved by technology

[0004] A large number of tests have proved that the zinc oxide fume is leached with an acidic acid using the traditional method. At the point of controlling the acid pH requirements at the end point of the germanium precipitation of tannins, that is, when the pH is 2.0~3.5, the germanium in the leach solution is only 20mg / l~30mg / l or so, indium is about 0.1mg / l~0.2mg / l, and silicon dioxide is as high as 4g / l~8g / l. Since a large amount of leached silicon forms silica gel at this time, its liquid-solid separation is very difficult, and the resulting The filtrate produced is not clear and has a lot of suspended matter; using this filtrate to carry out tannin precipitation of germanium is not only very difficult for liquid-solid separation, but the tannin ratio is as high as more than 50 times, and the germanium concentrate produced contains only 3wt%~6wt% germanium ; secondary acid leaching extraction recovery indium, although the liquid-solid separation is not so difficult, but because the filtrate contains silicon dioxide is also as high as 4g / l ~ 6g / l, containing indium is only 25mg / l ~ 35mg / l, resulting in The amount of extraction cycle is large, the organic phase is emulsified seriously, and phase separation is difficult, making it almost impossible to extract indium

In addition, the germanium and indium total extraction method was used for the test, also because the solution contains high silicon content, and the germanium and indium are relatively low, the extraction cycle is large, the organic phase is emulsified seriously, and phase separation is difficult, so it is almost impossible to extract germanium and indium. separate

Images