Abstract: In order to solve the problem that the presence of copper cyanide complexes (CuCN2-3 and CuCN3-4)and iron cyanide complex (FeCN4-6) in lixivium increases the consumption of NaCN and activated carbon in the process of gold ore cyanide leaching， the forms of copper and iron cyanide complexes in hypersaline system were discussed preliminarily， and the elimination efficiencies of these complexes by three different methods， i. e. the hydrogen peroxide oxidation， the chlorine oxidation and the acidification， were comparatively analyzed. The results showed that the elimination efficiencies of the copper cyanide complexes are over 99% by the three methods， while that of iron cyanide complex are 73%， 62% and 55%， respectively. The protonation is more effective for the elimination and decomposition of copper cyanide complexes and iron cyanide complex than oxidation in hypersaline system.

Key words: cyanide, complex, water treatment, hypersaline system, protonation