Low-Acid Extraction of Tantalum from a Tantalum-Niobium Pulp by MIBK

Abstract

The technological parameters and the mechanism of low-acid pulp extraction of tantalum were investigated. The results show that hydrofluoric acid concentration, sulfuric acid concentration, organic to pulp phase ratio, the concentration of tantalum and niobium, contact time and temperature have a significant effect; optimum process operating parameters were established as follows: hydrofluoric acid concentration 1.6 mol/L, sulfuric acid concentration 0.6 mol/L, organic to pulp phase ratio 3:1, tantalum concentration 26.61 g/L, niobium concentration 11.64 g/L, contact time 5min and room temperature. Under these experimental conditions, tantalum extraction can reach more than 98% and the separation factors of Ta/Nb, Ta/Fe and Ta/Sn were maximal.According to slope analysis, the equimolar series method and the saturation capacity method, the extraction product was identified as 3MIBK•H 2 TaF 7 .

Ketone functionalized task specific ionic liquids for selective tantalum extraction

“…According to Yang et al the extracted species was identified as MIBK:H2TaF7 of 3:1 ratio for the extraction of tantalum from sulphuric media containing hydrofluoric acid. [24] MIBK dissolves the tantalum and niobium compounds into the ketone while leaving impurities in the aqueous solution. Both niobium and tantalum are extracted at high concentration of H2SO4, but only tantalum is extracted at lower acidity.…”

A review on extractive metallurgy of tantalum and niobium

“…The extractant MIBK is often the preferred choice for Ta and Nb extraction (Ayanda and Adekola, 2011;Sanda and Taiwo, 2012;Yang et al, 2013;Nguyen and Lee, 2019). This is because it has low density (0.802 g/mL), low viscosity (0.58 mPa.s at 20 °C), low solubility in water (1.91 g/100 mL) and high selectivity (Agulyansky et al, 2004;Zhu and Cheng, 2011).…”

Evaluation of a Phosphinate Functionalized Ionic Liquid for the Separation of Nb and Ta from Nitric Acid Feed Conditions

“…Yang et al reported a β Nb/Ta value of ∼0.54 for extraction by MIBK when the aqueous phase was 0.6 N HF + 1.6 N H 2 SO 4 . The same solvent showed a reversal in the selectivity when the aqueous phase contained NH 4 .HF in less than 8 M H 2 SO 4 , where the β Nb/Ta value achieved was ∼0.14 . Mayorov and Nikolaev reported octanol (OCL)-based extraction from 2 M H 2 SO 4 in the presence of up to 2.4 M HF resulting in a β Nb/Ta value of ∼0.19, i.e., better extraction of Ta as compared to that of Nb .…”

“…The same solvent showed a reversal in the selectivity when the aqueous phase contained NH 4 .HF in less than 8 M H 2 SO 4 , where the β Nb/Ta value achieved was ∼0.14. 75 Mayorov and Nikolaev reported octanol (OCL)-based extraction from 2 M H 2 SO 4 in the presence of up to 2.4 M HF resulting in a β Nb/Ta value of ∼0.19, i.e., better extraction of Ta as compared to that of Nb. 76 In a separate report, a TBP- and OCL-based solvent when used against aqueous phases of 15.9 N HF and mixture of 6 N H 2 SO 4 + NH 4 F.HF resulted in β Nb/Ta values of ∼0.98 and 0.82, respectively.…”