METHOD OF RECOVERY OF NOBLE METALS FROM SILVER-CONTAINING CONCENTRATES Russian patent published in 2001 - IPC

FIELD: recovery of noble metals from flotation silver-containing concentrates. SUBSTANCE: method includes roasting of silver-containing concentrate in oxidation-reduction conditions to obtain in cinder sulfide-to-sulfate sulfurs ratio from 1:2 to 1:3. Then cinder is mixed with soda ash and calcite and prepared mixture is subjected to slag smelting with the following composition, wt. %: SiO₂, 41.6-47.5; Na₂O + K₂O, 22.0-31.4; CaO + MgO, 21.1-36.4; ratio of the mixture components is as follows, wt.%: cinder, 43.8-50.2; soda ash, 22.5-33.4; calcite, 16.4-33.6. EFFECT: reduced total consumption of fluxes due to exclusion of fluoride from mixture and partial replacement of expensive soda ash with calcite. 2 tbl, 2 ex