PURPOSE: To obtain a high-purity raw plating soln. from the material contg. by-product Zn in an iron works by charging the ZnO on one hand obtained by reducing and volatilizing the material in a final dissolution tank, charging the Zn on the other hand in a purification tank, and dissolving and purifying Zn.
CONSTITUTION: A Zn soln. is successively transferred 22AW22C from a first dissolution tank 17A to a purification tank 18, and a slurry contg. undissolved Zn is reversely returned 23AW23C from the tank 18 to the tank 17. Consequently, the Zn soln. is brought into countercurrent contact with the Zn-contg. slurry. ZnO powder is supplied to a third dissolution tank 17C as the final dissolution tank and dissolved in the Zn soln. supplied 22B, the soln. is supplied 22 to a vessel 13, Zn powder is supplied therein, and ion exchange purification is carried out. The purified soln. is transiently stored in a buffer tank 22, then supplied to plating equipment 23, and used as the raw plating material when a plated steel sheet is obtained from a steel sheet.
MARUKAWA YUJO
TATENO MASAKI
KISHINO SHIZUO
TANAKA KOGYO
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