Method for performing electrolytic refining on lead bullion

Abstract

The invention discloses a method for performing electrolytic refining on lead bullion, and belongs to the technical field of lead bullion refining. The method mainly comprises the following steps of: casting lead bullion obtained by fire refining, and electrolytic deposition refined lead into a lead bullion anode and an electrolytic deposition lead cathode in a melting state respectively; preparing a perchloric acid-lead perchlorate mixed solution, controlling the concentration of Pb<2+> to be 0.05 to 0.45 mol / L, controlling the concentration of perchloric acid to be 0.5 to 3.0 mol / L, controlling the temperature of electrolyte to be 5 to 65 DEG C, and performing electrolytic refining; and further adding an additive, and obtaining high-purity electrolytic lead further by a grading electrolytic method. The method is clean and saves energy and is suitable for industrial electrolytic refining of lead.

Description

technical field [0001] The invention belongs to the technical field of crude lead refining, and specifically relates to a method of casting crude lead obtained by pyrometallurgy into a crude lead anode after conventional pre-refining, and electrolytically refining by electrochemical method to obtain electrolytic lead or even high lead at the cathode and anode respectively. A method of purifying electrolytic lead and anode slime. Background technique [0002] After several decades of improvement, the existing pyrometallurgy process has become a very mature lead smelting process. Although the pyrometallurgy of lead has the advantages of high production efficiency and can be adapted to large-scale production, it is easy to reduce other metals together during the smelting process, resulting in the reduced lead often containing many other metal impurities, especially some silver and bismuth and other rare metals. The crude lead obtained by pyrometallurgy must be refined and rem...

AI Technical Summary

Problems solved by technology

[0004] Although the acidity of fluosilicic acid in the electrolyte is relatively weak, and the electrolysis temperature is low, the voltage of the electrolytic cell of this process is as high as 0.4-0.5V, and the current efficiency of the electrolysis process is only 92-96%, and the lead per ton Electrolysis energy consumption up to 120-135KWh

[0005] 2. Low production efficiency

[0006] Limited by the volatile characteristics of fluosilicic acid, the actual electrolysis generally uses a dilute fluosilicic acid solution and a lower temperature for electrolysis, which greatly restricts the improvement of the conductivity of the solution and the diffusion capacity of lead ions, so the actual electrolytic density is generally Controlled at 180-200A / m 2 , resulting in a cycle of electrolysis typically as long as 5-10 days

[0007] 3. High environmental toxicity

[0008] h 2 SiF 6 It is easy to volatilize, especially in summer, it is easier to produce a large amount of toxic acid mist at the work site, and the smell is unpleasant

In addition H 2 SiF 6 Also decomposes toxic HF and SiF 4 Gas, harmful to human body and environment

[0009] In order to overcome the shortcomings of the Baizi refining method, people have studied acidic systems such as fluorine boron salts and chlorides. Unfortunately, these studies have not achieved practical progress.

In recent years, some people have used the alkaline system for the electrolytic refining of crude lead. Because the concentration of lead in the alkaline electrolyte is too low, and there is no effective electrodeposition additive to control the electrodeposition process of the cathode, usually only Loose electrolytic lead, this kind of non-dense electrolytic lead is very easy to undergo secondary oxidation during the melting process, so the alkaline system electrolytic refining technology has not been recognized by people so far

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