Recovery of Cadmium and Cyanide using a Combination of Ion Exchange and Membrane Extraction

A combination of ion exchange and membrane extraction successfully recovered cadmium and cyanide from simulated cadmium-cyanide rinsewaters. The ion exchange loading was most effective at cyanidetocadmium molar ratios of 4:l or less; when the molar ratio exceeded 4:1, cadmiumcyanlde complexes caused a chromatographic displacement of free cyanide from the resin. Cyanide-to-cadmium molar ratios in excess of 4:l could be reduced to 4:l or less by pumping the solution through a sand filter loaded with cadmium oxide. Regeneration of the anionic resin with sulfuric acid restored the full resin capacity and recovered the cadmium and cyanide in separate solutions.