Abstract:Extraction of V(V) and Cr(III) from acidic sulfate leach liquors of ilmenite using 0.4 mol/L Aliquat 336 chloride in kerosene was carried out. Different parameters affecting the extraction process such as equilibrium time, sulfate concentration, Aliquat 336 concentration, equilibrium pH and the extraction temperature were investigated. Extraction of V(V) and Cr(III) by Aliquat 336 involved anion exchange mechanism, and the extracted species are [(VO₂SO₄)R₄N]_org at low equilibrium pH for V(V) and [R₄N-Cr(OH)₄]_org at high equilibrium pH for Cr(III). Calculated thermodynamic parameters show that the extraction process is endothermic reaction for V(V) and exothermic for Cr(III). Also, calculated values of DG_exand DS_ex indicate that the extraction reactions of V(V) and Cr(III) proceed as non-spontaneous reaction is more random. V(V) and Cr(III) were stripped, precipitated, separated and calcined at 500 °C for 2.0 h to produce the corresponding oxide in pure form after rinsing and drying.

Key words: extraction; acidic leach liquor; Aliquat 336; V(V); Cr(III)