METHOD OF REGENERATIVE PURIFICATION OF COPPER-AMMONIA ETCHING SOLUTIONS Russian patent published in 2008 - IPC C25B15/00 C22B3/20 C23G1/36 

FIELD: chemistry.

SUBSTANCE: invention relates to method of regenerative purification of copper-ammonia etching solutions. Method includes neutralisation of solutions with acidic agent, sedimentation of copper in the form of hard-soluble compound and separation of sediment from solution. Neutralisation involves using as acidic agent of hydrochloric acid solution or acidic solutions of copper plating to minimal values of content of residual copper in solution. Separated hard-soluble copper compound is regenerated by dissolving, obtaining copper chloride concentrate. After sediment separation, water is removed from solution and, in presence of organic solvent, ammonia chloride is isolated for preparation of galvanic solutions of copper plating. Organic solvent is regenerated by distillation, and residual copper is removed from solution during acidification by iron cementation.

EFFECT: regeneration of ammonia chloride and copper cations from solutions, their use in processes of galvanic solution preparation and purification of sewage water with content of copper cations lower than MPC values.

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