| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for treating an electrolytic solution, from an electrolytic solution containing sulfuric acid and organic acid after being used for alumite treatment, capable of separating eluted aluminum ions at high efficiency.SOLUTION: There is provided a method for treating an electrolytic containing sulfuric acid and oxalic acid after an aluminum base material is subjected to alumite treatment, including: a sulfuric acid concentration control step where the concentration of the sulfuric acid contained in the electrolytic solution is controlled to 325 g/L or higher; a crystallization step where the temperature of the electrolytic solution whose sulfuric acid concentration is controlled to 325 g/L or higher in the sulfuric acid concentration control step is controlled to 5 to 30°C, and this state is retained for a prescribed time, thus aluminum eluted in the electrolytic solution by the alumite treatment is crystallized out as aluminum sulfate; and a separation step where the aluminum sulfate crystallized out in the crystallization step is separated from the electrolytic solution.SELECTED DRAWING: Figure 1 |
