SOLVENT EXTRACTION OF GALLIUM(Ⅲ) WITH NONIONIC SURFACTANTS FROM HYDROCHLORIC ACID MEDIA

摘要

The solvent extraction of Ga(Ⅲ) from hydrochloric acid solutions using a nonionic surfactant having an average chain length of 10 ethylene oxide units (polyoxyethylene nonyl phenyl ether, PONPE10) as an extractant is described. Gallium(Ⅲ) is successfully extracted into a chloroform solution of the surfactant; the extraction improves with an increase in HC1 concentration and nearly complete extraction can be achieved from > 6M HCl solutions. The extraction efficiency increases with an increase in the ethylene oxide number of the surfactant, and varies with diluent in the order: chloroform < dichloromethane < dichloroethane. It has been found that the extraction takes place through the coordination of one surfactant molecule to one hydrogen tetrachlorogallate with all combinations of surfactant and diluent. The selective separation of Ga(Ⅲ) from some heavy metals has been demonstrated, as has back extraction from the metal-loaded solvents with a dilute HCl solution.