| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a system which discretely separates and recovers copper, sulfuric acid and nitric acid from an aqueous solution containing the copper, the sulfuric acid and the nitric acid, reuses these materials by resource recovery and is no discharge. SOLUTION: Copper materials are etched by an etching liquid W0 containing the sulfuric acid and the nitric acid, by which the aqueous solution W1 containing the copper, the sulfuric acid and the nitric acid is generated. When the aqueous solution W1 is heated in a sulfuric acid removing tank 30, the nitric acid is pyrolyzed and the nitric acid component is removed. When the aqueous solution W2 from which the nitric acid component is removed and which contains the copper and the nitric acid is subjected to an electrolytic treatment in a rotary electrolysis vessel 50, the copper component is recovered as metal copper and the aqueous solution W3 containing only the sulfuric acid is obtained. This aqueous solution W3 is reused again as the etching liquid. The discretely removed nitric acid and copper may also be reused by resource recovery. There is no discharge of the water to the outside.</p> |
