A study on metal cyanocomplexes sorption on polyacrylic ion exchange resins has been undertaken. Batch sorption experiments have shown that polyacrylic resins have a high affinity for zinc and iron cyanides compared to copper complexes. Elution studies performed in column experiments have also depicted that 1mo/L sodium thiocyanate solutions can successfully extract the three metals. Conversely, sodium nitrate solutions at the same concentration are not effective in eluting zinc cyanocomplexes. Based on elution figures, it is proposed that copper and iron can be selectively eluted with nitrate before the zinc, this latter being recovered afterwards with thiocyanate solutions. Both eluants were able to concentrate the cyanocomplexes in solution with a beneficial effect on the subsequent steps of cyanide recycling.
Cyanide; recycling; ion exchange resins; polyacrylic resins
