MECHANISM OF SOLVENT EXTRACTION OF GALLIUM CHLORIDE BY DI-(2-ETHYL HEXYL)PHOSPHATE(HDEHP)

In the present work, the solvent extraction of gallium (III) from all aqueousphase of chloride by di-(2-ethyl hexyl) phosphaie HDEHI, in benzene isinvestigated. The extractability of gallium chloride is determined as a functionof extraction time, extractant concentration, acidity and, gallium concentration. Itis found that the distribution coefficient for Ga (III) is proportional to thesecond power of the extractant concentration and the inverse second power ofhydrogen ion concentration. Suitable stripping conditions are found. In a pHrange of 1.5--2.2, the mechanism of galliuin extraction can be represented as thefollowing equation Ga~(3+)+Cl~-+2(HA)_(2(o))=GaCl(HA_2)_(2(o))+2H~+At a constant ionic strength(μ=0.025)and temperature(15℃)the correspondingequilibrium constant K is found to be 30.3.