Copper removal from diluted cyanide wast

Metal electrodialytic processes can utilize cyanide as a reagent, resulting in substantial amounts of industrial wastewater that contains both cyanide and heavy metals. Conventional treatment methods such as chemical precipitation produce toxic by-products including metallic hydroxides and sulfides. This study aims to develop an electrolytic cell designed to recover copper from diluted solutions that simulate the wastewater generated from the rinsing of copper electroplated dies, specifically in the context of coin manufacturing at the Brazilian Mint. The investigation assesses the impact of various process variables through both thermodynamic and volumetric evaluations. The results indicate that factors such as solution flow rate and temperature play crucial roles in enhancing reaction conditions. Notably, the presence of copper on the anode surface was found to catalyze cyanide oxidation. Optimal results were achieved at a temperature of 50°C with a total flow rate of 0.37 mL/s and a specific electrode configuration. Under these parameters, copper and free cyanide concentrations were recorded at 0.70 mg/L and 0.08 mg/L, respectively, with electric currents of 1.5 A and 2.0 A yielding lower concentrations in the solution. The study concludes with implications for improved wastewater management in the electroplating industry.