RU96113774A - METHOD FOR REMOVING SILVER FROM MATERIALS CONTAINING CHLORIDE SILVER, IMPURITIES OF GOLD AND METALS OF PLATINUM GROUP - Google Patents

Claims (3)

The method of extracting silver from materials containing silver chloride, gold impurities and platinum group metals, including melting the starting material in the presence of fluxes forming an alkali metal oxide, separating the resulting crude silver from slag, characterized in that the crude silver is melted when loaded onto the surface of the melt a layer of soda ash and when blowing the melt with dry air at 1100-1150 ^o C followed by granulation, then the granules are dissolved in a solution of nitric acid, separation f insoluble gold-containing residue by filtration, and a solution containing mainly silver nitrate is subjected to hydrolysis in the presence of sodium hydroxide to obtain pulp containing a precipitate of predominantly metal hydroxide impurities, including platinum metals, the pulp is filtered, silver is precipitated by electrolysis from the resulting solution and the hydroxide precipitate is dissolved in a minimum amount of nitric acid solution, the resulting solution is treated with sodium thiosulfate with the precipitation of concentrate platinum metals, are filtered and the resulting solution is combined with the solution after hydrolysis and subjected to electrolysis to obtain refined silver.  2. The method according to p. 1, characterized in that soda ash and / or lime, and / or dolomite flour, and / or nitric acid sodium are used as flux.  3. The method according to p. 1, characterized in that to reduce the consumption of sodium hydroxide before hydrolytic cleaning of the silver solution from impurities, nitric acid is distilled off by partial evaporation.