Abstract
For the purpose of recovering sodium hyroxide and zinc from waste water from low cyanide zinc plating baths, an electrolytic technique was investigated using cation exchange membrane as diaphragm. Granulated graphite anode used exhibited exellent durability and high efficiency for decomposing cyanide. Continuous operation tests showed that the recovering rates of sodium and zinc ions were 10.2mg/min and 1.4mg/min at diaphragm c. d. of 2A/dm2 (the area of the diaphragm on one side was 0.44dm2). Zinc was found to accumulate in the graphite anode as zinc hydroxide and zincate. The amount of zinc recovered was almost 90%.
