METHOD FOR ELECTROLYTICALLY REMOVING COPPER AND CYANIDE FROM ALKALI AND COPPER CYANIDE-CONTAINING SOLUTIONS

摘要

The invention relates to the removal of copper and cyanide from solutions containing alkali and copper cyanide, which occur after surface finishing processes in electroplating plants in more or less high concentration, by electrolysis for the purpose of detoxification and Metallrueckgewinnung. By addition of sodium thiosulfate and AeDTA in ratios according to the invention, in the presence of NaCl and subsequent addition of NaOH, the anodic and cathodic partial reactions are influenced so that the oxidative cyanide decomposition on the end products ammonia, nitrogen and carbon dioxide accelerates and completely dissipates over the electrolysis without these additives and the copper on the cathode is compact and evenly deposited. The advantages, reduced electrical energy consumption, time savings, low chemical consumption and favorable deposition of copper with low equipment costs are particularly useful when smaller amounts to be detoxified solutions incurred or the cyanide poisoning is not integrated into a complex wastewater treatment plant.