SOLVENT-EXTRACTION OF GALLIUM FROM AN INDIAN BAYER PROCESS LIQUOR USING KELEX-100

Solvent extraction of gallium from a concentrated Indian Bayer process liquor was studied using 7-alkyl-substituted-8-hydroxyquinoline (Kele x-100) as an extractant and iso-decanol and kerosene as a modifier and a diluent, respectively. The composition of the Payer process liquor was found to be approximate to 450 gpl of Na2O, approximate to 80 gpl of Al2O3 and 190 +/- 20 ppm of gallium. The recovery percentage and th e kinetics of extraction are; improved by increasing the concentration of Kelex-100 in the organic phase from 6 to 14 vol%. However, the ini tial rate of extraction was slowed down at 16 and 18 vol% of Kelex-100 . The initial rate of extraction was found to be improved by reducing the iso-decanol volume from 12 to 6% at 12 vol% of Kelex-100. The sodi um and aluminium up take of the organic phase was found to be decrease d with a decrease in the volume percent of iso-decanol. Minor addition s of petroleum sulfonate improves the kinetics of gallium extraction s ignificantly. The scrubbing of the loaded organic phase was found to b e best at 6.0M HCl with a 1.0:1.5 organic to aqueous ratio, whereas, s tripping was found to be best at 1.5M HCl with a 1.0:1.0 organic to aq ueous ratio. Copyright (C) 1996 Published by Elsevier Science Ltd.