METHOD OF REMOVING HEXACYANOFERRATES FROM WASTE WATERS Russian patent published in 2006 - IPC C02F1/58 C02F101/18 C02F103/40 

FIELD: waste water treatment.

SUBSTANCE: invention relates to treatment of waste waters from gold mining enterprises, movie and photo industry as well as productions involving hexacyanoferrates. Waste waters containing hexacyanoferrates (II and III) preliminarily acidified with sulfuric acid are passed at ambient temperature through charge consisting of mixture of iron cuttings (metal machining waste) and coke taken in equal proportions while simultaneously supplying air oxygen. Precipitated insoluble mixed ferro- and ferricyanides are separated by filtration. Proposed method increases productivity and efficiency of treating water, expands possibilities of galvano-coagulation method for treating waste waters so allowing detoxification of stable complex heavy metal cyanides (hexacyanoferrates) and, at the same time, removal of heavy metal ions from effluents, reduced waste water treatment time, and also reduction of process expenses due to eliminated additional introduction of reagents and heating of solutions. Advantage of the method is further utilization of production waste (metal machining waste) and coke. In addition, the obtained precipitates can be used as paint pigments.

EFFECT: enhanced process efficiency.

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