PHOTO CATALYTIC DETOXIFICATION OF CYANIDE AND METAL CYANO-SPECIES FROM PRECIOUS-METAL MILL EFFLUENTS

Photochemically-induced detoxification of various cyanide species from a selected precious-metal mills tailings was investigated in detail. The studies were conducted in the presence or absence of a titanium(IV ) oxide semiconductor photocatalyst utilizing simulated sunlight as th e irradiation source. It was established that the cyanide ion (both fr ee and complexed) was photocatalytically oxidized to nitrate via cyana te and nitrite. In addition iron, copper, zinc, mercury and arsenic we re stabilized as precipitates. The results obtained may have ramificat ions for the possible use of solar energy for the efficient treatment of large quantities of precious-metal mill-tailing wastes that contain various cyano-species.