隔膜電解法による低シアン亜鉛めっき排水の工業的濃縮回収

抄録

Waste water from low cyanide zinc plating baths was electrolyzed in an industrial scale to recover alkali and zinc and to decompose cyanide. Granulated graphite anodes and cation exchange membranes as diaphragms were used in constructing our electrolytic cell. The rate of recovery of plating solution was about 4.8l/h at a total current of 300A (diaphragm c.d.: 2A/dm²). The percentage for the recovery of alkali and zinc was found to be 104 and 92.7%, respectively, and 85.7% of cyanide was decomposed. Almost all zinc was accumulated on the graphite anode as zinc hydroxide and sodium zincate.