US 12,221,366 B1
Method for recycling copper-containing wastewater from micro-etching
Chenyang Zhang, Changsha (CN); Mingjun Han, Changsha (CN); Wei Sun, Changsha (CN); Jie Li, Changsha (CN); Wenjihao Hu, Changsha (CN); Heng Yu, Changsha (CN); Rong Wang, Changsha (CN); Siyuan Liu, Changsha (CN); Xiangsong Meng, Changsha (CN); and Pan Chen, Changsha (CN)
Assigned to CENTRAL SOUTH UNIVERSITY, Changsha (CN)
Filed by Central South University, Changsha (CN)
Filed on Aug. 14, 2024, as Appl. No. 18/804,147.
Int. Cl. C02F 1/52 (2023.01); C01G 49/12 (2006.01); C02F 1/66 (2023.01); C02F 101/20 (2006.01); C02F 103/34 (2006.01)
CPC C02F 1/5236 (2013.01) [C01G 49/12 (2013.01); C02F 1/66 (2013.01); C01P 2004/03 (2013.01); C02F 2101/20 (2013.01); C02F 2103/346 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A method for recycling a copper-containing wastewater from a micro-etching, comprising adding a FeS-based pH-responsive material to a weakly-acidic copper-containing wastewater from the micro-etching, to allow a reaction I to obtain a precipitate with CuS as a main component, wherein
the FeS-based pH-responsive material is prepared through the following process: slowly adding a sulfide salt solution to a mixed solution comprising a modified crosslinking agent, a stabilizing and dispersing agent, and a ferrous salt, to allow a heterogeneous precipitation reaction to obtain the FeS-based pH-responsive material; wherein the modified crosslinking agent is obtained through a crosslinking reaction of a monomer comprising both carboxyl and sulfhydryl with a crosslinking agent;
the reaction I is conducted at a pH value of 3.95 to 6.05 for 10 min to 25 min;
a Cu2+/S2− molar ratio of the copper-containing wastewater from the micro-etching to the FeS-based pH-responsive material is 1:(1.0-1.25);
the monomer comprising both the carboxyl and the sulfhydryl comprises at least one of mercaptopropionic acid, mercaptoacetic acid, and mercaptoacrylic acid;
the crosslinking agent is nanoscale silica; and
a molar ratio of the monomer comprising both the carboxyl and the sulfhydryl to the crosslinking agent is (1.0-1.6):1.