SOLVENT-EXTRACTION OF GALLIUM WITH KELEX-100 FROM BRAZILIAN WEAK SODIUM ALUMINATE SOLUTION

This work shows the partial studies developed for the recovery of gallium from industrial sodium aluminate solutions (Bayer liquors) through solvent extraction provided by a Brazilian aluminium plant. Over 90% Ga was extracted within 2 minutes, with the use of a solvent made up of 10 vol % Kelex 100, 5 vol % Versatic 10, 8 vol % n-decanol and kerosene. The aqueous feed (Bayer Liquors) used was made up of 0.10 - 0.11 g/l Ga, 16 - 25 g/l Al2O3 and 108 - 120 g/l Na2O. Selective stripping was carried out in two ways: the first one for the scrubbing of the two major contaminants (Al and Na) and the second for the stripping of gallium. Loaded solvent containing over 0.5 g/l Ga was not suitable for scrubbing of aluminium and sodium. Thus, a loaded solvent containing up to 0.1 g/l Ga was used and a slightly purified strip liquor with 1.12 g/l Ga was obtained.