METHOD OF ELECTROPLATING INDUSTRY WASTE WATERS CLEARING FROM HEAVY METALS Russian patent published in 1995 - IPC

FIELD: electroplating industry waste waters clearing. SUBSTANCE: electroplating industry waste waters are treated with motor oil addition production sulfurous alkali waste, that has experimentally determined pH value, till achievement of definite value of platinum electrode reduction-oxidation potential relatively to silver chloride electrode. Then they allow it to settle for 15 - 20 minutes and separate formed sediment by filtering. Copper settling out is exercised with pH = 5.5 - 6.0 till value of reduction-oxidation potential achieves -280 - 320 mV, zinc and cadmium settling out = with pH = 8.9 - 9.0 till value of reduction-oxidation potential achieves -200 - 240 m V, nickel settling out - with pH = 11 - 12 till value of reduction-oxidation potential achieves -90 - 125 mV, tin and bismuth settling out - with pH = 7.0 - 8.0 till value of reduction-oxidation potential achieves -730 - 770 mV. Produced settlings of heavy metals sulfides are sent to metallurgical works for processing to produce corresponding metals. Filters are used as tempering liquid in concrete production. EFFECT: method is used for electroplating industry waste waters clearing. 6 cl, 4 tbl