Extraction and recovery of Ga(III) from waste material using Cyanex 923

The extraction of Ga(III) from HCl, HNO3 and H2SO4 media using 0.50 mol/L Cyanex 923 in toluene is investigated. Ga(III) is quantitatively extracted over a wide range of HCl at high concentration while the extraction is poor over the entire concentration range of HNO3 and H2SO4. The extracted Ga(III) is recovered by stripping with 0.10 mol/L HCl. The extracted species is identified as GaCl(3.)3Cyanex 923. The extraction behaviour of some commonly associated metal ions is also investigated. Based on the partition data, conditions have been identified for attaining some binary and ternary separations involving Ga(III) and V(IV), Al (III), Fe(III), ln(III), Ti(IV), Ni(II), Mn(II), Cu(II), Zn(II), and Hg(ll). The conditions are extended for the recovery of pure gallium from light emitting diode (LED) waste and bottom ash. The extractant is stable towards prolonged acid contact and there is a negligible loss in its extraction efficiency even after recycling ten times. (C) 2007 Elsevier B.V. All rights reserved.