Natural Cyanide Attenuation in a Tailings Dam in South-Western Ghana

S.A. Ndur ； J.M. Doe ； E.K. Asiam

《Research Journal of Environmental and Earth Sciences》 7卷2期 (2015/05) Pp. 24-28

並列摘要

The aim of this study was to investigate the viability of light and aeration (oxygen) in cyanide attenuation of gold tailings material in a tropical environment. It was established that under aeration conditions free cyanide (CN_F) concentration reduced from 200 mg/dm^3 to below 0.03 mg/dm^3 in 60 h weak acid dissociable cyanide (WAD_(CN)) concentration reduced from 200 mg/dm^3 to 6 mg/dm^3 after 60 h. Under non-aeration conditions CN_F concentrations reduced from 200 mg/dm^3 to 60 mg/dm^3 within 108 h, the pH reduced from 10.80 to 9.41. WAD_(CN) concentration decreased from 200 mg/dm^3 to 73 mg/dm^3 within 48 h. It then increased to 150 mg/dm^3 after 60 h and then gradually decreased to 100 mg/dm^3 after 144 h. It was inferred that volatilisation of HCN was the dominant mechanism accounting for degradation of CN_F Degradation of complex cyanide species and this was enhanced by sunlight and aeration. It was concluded that natural cyanide attenuation is possible but the rate of degradation particularly for WAD_(CN) is not as fast as free cyanide. Hence it is not a suitable process for cyanide degradation in tropical environment.

並列關鍵字

Aeration ； attenuation ； cyanide ； natural ； sunlight ； tailings dam