METHOD FOR OBTAINING CONCENTRATE OF PRECIOUS METALS FROM PRODUCTS OF ORE PROCESSING AND SECONDARY RAW MATERIALS Russian patent published in 2018 - IPC C22B11/00 C22B3/04 

FIELD: technological processes.

SUBSTANCE: invention relates to the preparation of a concentrate of precious metals from products of ore processing. Products of processing are crushed. Mixture is prepared from sodium hydroxide, borax and quartz sand in a ratio by weight 1:(0–0.6):(0.3–0.9):(0–0.3). Required amount of sulfur and nickel or their compounds is calculated taking into account their content in the raw materials to be processed and ensuring the production of nickel matte with a sulfur to nickel ratio of 0.34 to 0.38 and a mass of at least 3 % of the total mass of fluxes and the products mentioned. Said mixture is melted at a temperature of 1,000 °C to 1,300 °C to produce nickel matte. Matte is crushed to a particle size of less than 0.08 mm, then leached in hydrochloric acid at a temperature of 75 °C to 100 °C for 15 to 120 minutes to obtain the concentrate of precious metals. Hydrogen sulfide released during leaching is fed to an alkali solution for absorption, using this solution nickel is precipitated in the leaching solution after separation of the concentrate of precious metals and neutralization to pH 7–8. Precipitate of nickel sulfide is filtered off, nickel is precipitated as hydroxide in the filtrate. Nickel-containing precipitates are dried and used as burden materials.

EFFECT: method allows to obtain a concentrate with the content of precious metals of up to 40–60 % with the extraction of 97–99,6 % of valuable components.

5 cl, 4 dwg, 6 ex