RU95116518A - METHOD FOR HYDROMETALLURGIC EXTRACTION OF METALS FROM COMPLEX ORE - Google Patents

Claims (8)

1. A continuous hydrometallurgical method of converting copper and / or zinc sulfides into the recoverable precipitates of their corresponding sulfates in the presence of nitric acid while minimizing the emission of nitrogen and N ₂ O gases, in which copper and / or zinc sulfides obtained from ores are in contact with sulfur and nitric acid to form a reaction mixture in an acidic solution, characterized in that the reaction mixture is maintained at a temperature in the range of 110 to 170 ^{° C.} with continuous stirring of the reaction mixture; add sufficient sulfuric and nitric acid to the reaction mixture to form a light colored precipitate and a dark colored precipitate in the reaction mixture, while the light precipitate contains water-soluble copper and / or zinc sulfates, and the dark precipitate is water-insoluble and contains sulfur and gangue; introducing an oxygen source into the reaction mixture to accelerate in the presence of nitric and sulfuric acid the oxidation of sulfides to sulfates and the oxidation of gaseous products of the NO _x reaction for the regeneration of nitric acid used in said reaction mixture; light and dark precipitates and entrained acidic solution are removed from the reaction mixture; light and dark precipitates are separated from the acid solution to treat the light precipitate in order to extract copper sulfate and / or zinc sulfate from the light precipitate, and the acid solution is recycled to the reaction mixture.  2. The method according to claim 1, characterized in that the finely dispersed ore concentrate containing copper and / or zinc sulfides is contacted with sulfuric and nitric acids in the reaction mixture.  3. The method according to claim 1, characterized in that the ore concentrate is obtained from the ore body of chalcopyrite, sphalerite or other sulfide minerals.  4. The method according to claim 1, characterized in that the iron in the form of part of a copper-iron sulfide in chalcopyrite ore concentrate is converted in the reaction mixture to iron sulfate, which precipitates in an acid solution and, as a result, forms part of a light precipitate, with the conversion of copper in recoverable sediment.  5. The method according to claim 1, characterized in that a sufficient amount of sulfuric acid is added to the reaction mixture to maintain the volumetric concentration of concentrated sulfuric acid in the reaction mixture to the volume of the reaction mixture in the range from 35 to 65 vol / vol% per volume.  6. The method according to claim 5, characterized in that in order to maintain a molar concentration of nitric acid in the reaction mixture of at least 0.5 moles of nitric acid per mole of copper sulfide, a sufficient amount of nitric acid is added to the reaction mixture.  7. The method according to claim 6, characterized in that the molar concentration of nitric acid is in the range from 0.5 moles to 3.0 moles per mole of copper sulfide, and the concentration of sulfuric acid is in the range from 40 to 65 vol.% Per volume .  8. The method according to claim 7, characterized in that copper and zinc are extracted from the combined dark and light precipitate by treatment with water to dissolve and remove soluble salts of copper sulfate and zinc sulfate from said precipitate.