METHOD FOR LEACHING METALLIC COPPER Russian patent published in 2021 - IPC C22B15/00 C22B3/08 C22B7/00 

FIELD: chemistry.

SUBSTANCE: invention relates to methods for dissolving copper, it can be used for processing secondary waste in the form of copper chips, crumbs, slags, dust or ash, including electronic scrap. Metallic copper from a copper-containing material is leached in a solution of sulfuric acid with the addition of an oxidizer when heating and applying an alternating current of industrial frequency using insoluble electrodes. Leaching is carried out in the mode of percolation of a leaching sulfuric acid solution through a layer of copper-containing material. As a sulfuric acid solution, a spent electrolyte of the composition 10 g/dm³ of CuSO₄ and 100 g/dm³ of H₂SO₄ is used. As an oxidizer, nitric acid with a concentration of 56% is used at a ratio of 2.7-3.3 mole of HNO₃ per 1 mole of Cu. The nitrogen oxides formed in the reaction are removed with a nitrogen current through a fitting located on the lid of the electrolyzer.

EFFECT: method provides increased safety of the copper dissolution process, as well as the secondary use of the spent electrolyte and its disposal, and increased rate of copper dissolution.

1 cl, 1 tbl