Process for extracting tin from wet lead with high tin content

Abstract

The invention relates to a process for extracting tin from wet lead with high tin content. The process comprises the following steps: removing parts of impurities of copper, arsenic, stibium, and the like according to the traditional technological means in an initial fire refining process, raising temperature to 700 to 800 DEG C, adding alkaline oxidizers of sodium nitrate, sodium hydroxide, and the like to oxide tin for slagging, and stirring for a long time to make materials fully react. The invention adopts a high temperature alkali method to oxidize tin , separate tin from lead and recover tin in a mode of tin oxide slag. The effect that tin content of an anode plate is below 0.06 % is achieved, the average direct yield of tin content of tin slag is 96.58 %, and the tin content in wet tin is basically extracted from the tin slag completely.

Description

technical field [0001] The invention relates to a process for extracting tin from high-tin crude lead. The high-tin crude lead referred to in the present invention is crude lead produced by smelting lead ore symbiotic with tin ore, and its tin content percentage by weight is as high as 1-4%. Background technique [0002] Purification of crude lead into refined lead is called lead refining. Its process is to remove impurity metals. In my country, electrolysis is generally used as the process of lead refining. The process can be briefly described as: primary refining by fire method, which is usually called melting lead pot Slag removal → anode plate → electrolytic refining → lead precipitation → final refining, which is usually called electric lead pot slag removal → electric lead. In the process of lead electrolysis, the electrode potential of the impurity metal tin in crude lead is -0.136V, while the electrode potential of lead is -0.127V, the two are very close, so metal ti...

AI Technical Summary

Problems solved by technology

[0005] However, the above-mentioned method is for the treatment of high-tin crude lead with a tin content as high as 1 to 4%, and the precipitated lead and tin impurities on the anode plate will reach more than 0.6%, which will seriously affect the quality of the electrical lead.

[0006] The patent technology closely related to the present invention is a kind of " crude lead pyro-refining new technology " disclosed on March 30, 1988 by Chinese Invention Patent Publication No. CN87104574A. Sodium hydroxide is added to the refining pot, and compressed air and oxygen are introduced at a temperature of 600 to 630 ° C. The compressed air and oxygen are mixed at a ratio of 4:1, and then blown into the melt through the air duct, with a pressure of 3 to 4 kg / cm. 2 Arsenic, antimony and tin impurities in crude lead are oxidized and removed with sodium hydroxide to generate corresponding salts.

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