MECHANISM OF COMPETITIVE REACTION IN ANTAGONISTIC EXTRACTION OF CADMIUM AND ZINC WITH DI(2-ETHYLHEXYL) DITHIOPHOSPHORIC ACID-DIOCTYLAMINE
The antagonistic extractions of cadmium and zinc with di(2-ethlhexyl)dithiophosphoric acid (D2EHDTPA)-dioctylamine (DOA) were investigated. The diagram of synergistic extraction showed that the extraction of cadmium and zinc are antagonistic.The extracted complexes were CdA 2 and ZnA 2.There were three reactions in the extraction, their contributions to the extraction changed with pH, and the U shaped curve of lg D -pH in the extraction of cadmium could be explained with the three reactions.