Dore silver electro-refining process

Abstract

The invention discloses a dore silver electro-refining process. The dore silver electro-refining process includes the following steps of (1) preparation of a silver nitrate solution; (2) immersion silver reaction; (3) preparation of silver electrolyte; and (4) silver electro-refining. According to the dore silver electro-refining process, silver nitrate serves as the electrolyte, a dore silver alloy anode and a pure silver plate cathode are put in the silver nitrate electrolyte during electrolysis, after direct current is led in, silver and base metal impurities at the anode are dissolved, pure silver is separated out at the cathode, the pure silver is tested, washed to be neutral and dried in a spinning mode, and silver ingots are cast. On the premise that technical and economical indicators are identical with those of imported equipment, the structure is more simple and reasonable, operation is more convenient, and investment on equipment and accessories is greatly saved. Compared with a silver electrolytic cell with the same volume, the yield of an electrolytic cell in the dore silver electro-refining process is doubled or above compared with the common electrolytic cell. Therefore, the dore silver electro-refining process disclosed by the invention has good popularization and demonstration effect in the industry.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, in particular to a crude silver electrolytic refining process. Background technique [0002] The silver electrolysis process belongs to the redox reaction. The metal silver at the anode continuously loses electrons and is oxidized to positive silver ions (Ag + ) into the solution, and at the same time, the positive silver ions in the solution are constantly moving towards the cathode direction under the promotion of the electric field, and after reaching the cathode, they obtain electrons and are reduced to metallic silver. Silver electrolysis is the whole process in which silver is converted from anode to ions and reduced to metal at the cathode. [0003] At present, most of the electrolytic cells used in the large-scale silver electrolytic refining industry are crawler-type horizontal electrolytic cells that automatically discharge silver powder, also known as boat-shaped cells. The advan...

AI Technical Summary

Problems solved by technology

However, the current density of this kind of electrolyzer routinely used in China is relatively small (generally 250-350A / m 2 ), the electrolysis speed is low, the electrolyte in the equipment is relatively large, and the capital occupation is large and the turnover is slow

[0004] In addition, under the severe situation of national environmental protection, the waste gas treatment in the process needs to be reasonable and perfect. In the production of gold and silver extracted from gold mud, it is usually through several steps such as nitric acid removal, aqua regia dissolution of gold, and sodium sulfite reduction. However, in the above process, a large amount of yellow smoke (flue gas containing nitrogen oxide gas) and other acidic smoke (HCl / SO 2 ), which not only pollutes the environment, but also carries a serious loss of precious metals

Images