Abstract: The present invention provides a method of separating precious metals from anode sludge obtained from copper electrolysis, comprising (a) leaching the anode sludge in an aqueous sulfuric acid solution to remove leachable chlorides and to obtain a first leaching residue depleted of chlorides; (b) pressure leaching the first leaching residue to dissolve Ag and Se and to obtain a first filtrate comprising Ag and Se and a second leaching residue depleted of Ag and Se; and (c) leaching the second leaching residue with an aqueous hydrochloric acid solution to dissolve Au and PGMs to obtain a second filtrate comprising Au and PGMs and a final leaching residue.

Abstract: The present invention provides a process for recovering valuable metals from precious metal smelting slag, comprising: smelting the precious metal smelting slag and a flux in a top-blown rotary furnace to produce a lead-bismuth alloy, wherein the precious metal smelting slag comprises Au, Ag, Bi and Pb; electrolyzing the lead-bismuth alloy at a current density ranging from 60 to 110 A/m2 to obtain lead cathode and lead anode slime; refining the lead anode slime to produce bismuth and silver-zinc crust, and extracting gold and silver separately from the silver-zinc crust. Through utilizing a top-blown rotary furnace as the smelting apparatus and adjusting the ratio of the flux, the present invention enriches the valuable metals gold, silver, bismuth, lead or the like to lead-bismuth alloy, ensures lower contents of gold, silver, bismuth and lead in the reducing slag and thereby increases the comprehensive recovery rates of gold, silver, bismuth and lead from the precious metal smelting slag.

Abstract: The invention relates to a hydrometallurgical method for separating the precious metals and impurities of anode sludge obtained from copper electrolysis. According to the method, anode sludge copper is separated in atmospheric leaching; calcinated in two steps for separating selenium and for sulfatizing silver; the sulfatized silver is separated by leaching into a neutral aqueous solution, from which it can be separated by reduction or by extraction.

Abstract: The method and furnace according to the invention enable a continuous processing of anode slime and are particularly suited to be connected to a process where anode slime is treated by hydrometallurgic methods after roasting. In the method according to the invention, the slime containing valuable metals and selenium is dried, roasted, sulfatized and cooled. The method includes steps to be carried out in succession, in continuous operation, so that the slime forms a slime layer on the conveyor and is conveyed to be treated in successive drying, roasting, sulfatizing and sulfuric acid removal and cooling units.

Abstract: This process comprises; mixing (1) the solid residues with a solid reducing agent; treating (2) the mixture in a furnace at a temperature above 1000.degree. C. to obtain (3) a vitrified product rendered poor in metals and an emission of gas enriched in metallic elements in a vapour phase; air quenching (4) the gases rich in metals; filtering (5) the products resulting from the air quenching to obtain secondary ashes rich in metallic salts; at the end of the filtering operation, washing the smoke (6) for discharging it to the atmosphere; and subjecting the secondary ashes rich in metallic salts to a treatment for producing a product rich in valuable metals (7 to 10).