DEVICE FOR RECOVERING VALUABLE COMPONENT OF CHEMICAL PLATING SOLUTION AND VALUABLE COMPONENT RECOVERY

摘要

PROBLEM TO BE SOLVED: To recover a chelating agent contained in a chemical copper plating waste soln. from the waste soln. from which metal ions are recovered and to recover sodium formate from the waste soln. as formic acid. SOLUTION: An aged chemical copper plating soln. 2 in a chemical copper plating tank 1 is transferred to a waste soln. storage tank 5 and heated by a heater 6 to an optimum temp. for the plating reaction, and copper is circulated and filtered off by a filter 10. A chelating agent and formic acid are recovered from the waste soln. freed from copper. The waste soln. freed from copper is transferred to a crystallization tank 14, admixed with sulfuric acid 18 in a tank 17 and agitated by an agitator 13, hence the pH is decreased to =2, and the chelating agent contained in the chemical copper plating soln. 2 freed from copper ion is crystallized. The waste soln. contg. the crystallized chelating agent is sent to a filter 20, and the agent is filtered off. The filtered waste soln. is distilled in a vacuum distiller, and the vaporized formic acid is liquefied in a cooler 23 and recovered in a formic acid recovery tank 25.