Separation of vanadium using both hollow fiber membrane and solvent extraction technique - A comparative study

A comparative study between solvent extraction and hollow fiber membrane technique has been carried out for the extraction of V (V) from an aqueous chloride solution. LIX 84I has been used as carrier/extractant. Also the extraction of vanadium in presence of various other metals, such as iron, copper, zinc, cobalt, nickel and manganese using hollow fiber supported liquid membrane (HFSLM) has been studied. Effect of different parameters such as pH of feed solution, flow rate, extractant concentration, metal ion concentration and strip solution concentration on vanadium extraction has been investigated. With increase of pH, extractant concentration and flow rate, the flux value increased up to certain level and then decreases. The flux increased from 1.0 to 1.82 × 10−5, 0.97 to 1.82 × 10−5 and from 0.6 to 1.82 × 10−5 mol/m2.s with increase of pH, [extractant] and flow rate from 1.0 to 1.75, 0.08 to 0.32 M and from 105 to 290 mL/min, respectively. The extracted species was determined to be VO2R·RH. Vanadium was extracted selectively and separated completely from a multi metal bearing solution by using hollow fiber membrane module and the separation factor values were found to be in the order of αV/Cu < αV/Fe < αV/Zn < αV/Co < αV/Mn < αV/Ni. The data generated from the hollow fiber study were compared with that of conventional mixer-settler study. High purity (99%) V2O5 was produced from the strip solution by precipitation with H2SO4 at pH around 2.0.