The salting-out effect of various solutions of electrolyte in the extraction of tantalum and niobium using aqueous biphasic system (ABS) was investigated. This was achieved by leaching ball-milled Tantalite ore with mineral acids (H2SO4 and HF) in the ratio of 3:1. The leached liquor was then divided into five parts and each part mixed with ABS formed (e.g. PEG-3350/20wt/wt Na2CO3) for the extraction of tantalum and niobium and then with Na2SO4, K2CO3, K2SO4, KBr, and KI salts in turn. The amount of tantalum pent oxide extracted was determined using X-ray fluorescence method. The results show that the percentage tantalum extracted was in the range of 28.17% to 54.93% i.e. increased in the order KI< KBr < K2CO3< Na2SO4, < K2SO4 with 28.17%, 30.28%, 34.51%, 43.31% and 54.93% respectively; while that of niobium pent oxide increased in the order KI< KBr < K2CO3< Na2SO4, < K2SO4 with 27.3%, 29.35%, 33.78%, 34.64% and 41.98% respectively. In conclusion electrolyte with high ionic charge and hydration radius salts-out Ta2O5 better in the ABS/electrolyte system than those with low values.
Key words: Tantalum, niobium, salting-out, extraction, aqueous biphase
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