METHOD FOR REGENERATING FREE CYANIDE BY SELECTIVE OXIDATION OF THIOCYANATES Russian patent published in 2018 - IPC C02F1/72 C01C3/20 C02F101/18 C02F103/16 

FIELD: mining.

SUBSTANCE: invention can be used in mining, gold mining and non-ferrous metallurgy industries to regenerate free cyanide from water and pulp containing thiocyanates, and also for their purification from these compounds. Method includes oxidizing treatment of water or pulp at pH of less than 6.0, purging and trapping the prussic acid from the waste gases to an alkaline scavenger, alkalizing the water or pulps after their oxidative treatment. Part of the water or pulp after oxidative treatment or purging of hydrocyanic acid is directed to be mixed with the feed in a ratio such that the pH of the mixture is 1.5–2.5. Water or pulp can be purified simultaneously with the regeneration of free cyanide at any given depth, while cyanides may be present in addition to thiocyanates. Treatment is carried out both in the batch and continuous modes, the prussic acid from the exhaust gases is trapped with alkaline waters or pulps.

EFFECT: method provides a reduction in the consumption of reagents during the regeneration of free cyanide while maintaining a high degree of their recovery.

5 cl, 6 dwg, 9 tbl, 9 ex