1991 Volume 24 Issue 1 Pages 15-20
A process has been developed to recover gallium and vanadium from coal fly ash in which they exist at very low concentration in a mixture of high concentration of less desirable species. Aqueous solution containing 2.8 mg/l gallium and 35 mg/l vanadium was obtained by leaching with 1.5 mol/l sulfuric acid. These metals were then concentrated by use of a chelating resin column with a functional group of iminodiacetic type after reduction of ferric ion to ferrous ion and pH adjustment. the eluate was conditioned and passed again through the column. Gallium was concentrated to 4.0 g/l and vanadium to 26.0 g/l in the resulting eluate. This liquor was further treated to remove impurities by a solvent extraction technique, employing TOMAC and D2EHPA as extractants. Stripping solutions of 96.6% gallium purity and 94.8% vanadium purity were finally obtained.
