Trisodium citrate → Copper

Participants

Reaction Steps

A 2:1 molar ratio of copper sulfate and trisodium citrate, respectively, and benzotriazole (BZT) were mixed in DI water to yield a 50 ppm copper and 25 ppm BZT CMP synthetic filtrate with a pH of 3.70. To aliquots of this solution mixing at 100 rpm, a polymeric chelant in the absence of a coagulant or a coagulant in the absence of a polymeric chelant was charged then allowed to mix for 15 minutes. Treated aliquots were filtered using a 0.45 micron filter. The isolated filtrate was then analyzed for pH and copper content via ICP, the results of which are summarized in Table 1. Test results demonstrated that non-dithiocarbamate polymeric chelant and coagulant as separate treatments are not as effective in precipitating copper from the test matrix.

Provenance & Evidence