Only implementation of a reliable system of impurities removal at all refining stages allows producing of high purity gold and silver. Conditions and methods of more complete treatment of silver electrolyte have been developed including two stages: sorption of platinum group metals by means of ion exchange resins and hydrolytic precipitation of copper and tellurium. Uniform and strictly metered solution hydrolysis and flocculating agents were used to extract non-ferrous metals and tellurium from silver bearing electrolyte that increased silver recovery to final products and the quality of commercial silver. Electron microscopy and microanalysis were employed to identify slime phase composition after silver-and-gold alloy leaching by nitric acid. X-ray microanalysis showed that gold bearing slime sample contains silver selenide (Ag 2SeO 3), fine crystals of metallic gold and small amount of metallic silver. To exclude selenium from process flow-sheet a method of slime alkali treatment was elaborated and is currently used at production scale. Exclusion of selenium from the first stage of silver-and-gold alloy refining positively influences to the stages of nitric acid conditioning by increasing extraction of silver and platinoids to the solution and prevents emission of selenium dioxide to working area air at gold smelting to granules and improves quality of silver bullions due to lack of cathode silver contamination with selenium circulating in the silver-and-gold alloy refinery cycle. Improvement of precious metals refinery technology in terms of more efficient removal of impurities from solution and solid inventories allows processing various raw materials including those with low content of gold and silver and containing precious metals, concentrates and wastes. Adopted technological solutions provides stable production of commercial refined products of high purity.
|Título traduzido da contribuição||Improvement of affinage technology on JSC “Uralelectromed”|
|Número de emissão||10|
|Estado da publicação||Published - 2012|
- 53.00.00 METALLURGY
Level of Research Output
- VAK List