Patent ID: 11939229
Assignee: CENTRAL SOUTH UNIVERSITY
Field: Environmental technology (Chemistry)
Classification: CPC C | IPC C

Claim 1:
2. The method according to claim 1, wherein in the step S3, the acidic waste etching solution is classified into a low-impurity acidic waste etching solution and a high-impurity acidic waste etching solution, and the alkaline waste etching solution is classified into a low-impurity alkaline waste etching solution and a high-impurity alkaline waste etching solution;
wherein the low-impurity acidic waste etching solution is an acidic waste etching solution with an iron concentration less than 25 ppm, an aluminum concentration less than 5 ppm and an arsenic concentration less than 0.5 ppm; the high-impurity acidic waste etching solution is an acid waste etching solution satisfying one or more of the iron concentration greater than or equal to 25 ppm, the aluminum concentration greater than or equal to 5 ppm and the arsenic concentration greater than or equal to 0.5 ppm; the low-impurity alkaline waste etching solution is an alkaline waste etching solution with the iron concentration less than 25 ppm, the aluminum concentration less than 5 ppm and the arsenic concentration less than 0.5 ppm; and the high-impurity alkaline waste etching solution is an alkaline waste etching solution satisfying one or more of the iron concentration greater than or equal to 25 ppm, the aluminum concentration greater than or equal to 5 ppm and the arsenic concentration greater than or equal to 0.5 ppm;
in the step S4, when the acidic waste etching solution is the low-impurity acidic waste etching solution, the ammonium-containing solution reacting with the low-impurity acidic waste etching solution comprises the low-impurity alkaline waste etching solution; and when the acidic waste etching solution is the high-impurity acidic waste etching solution, the ammonium-containing solution reacting with the high-impurity acidic waste etching solution comprises the ammonia solution; and
in the step S5, the alkaline waste etching solution is the high-impurity alkaline waste etching solution.