Extraction and Separation of Tantalum and Niobium by Liquid-Liquid Extraction in the HF-H<SUB>2</SUB>SO<SUB>4</SUB>-TBP System

Abstract

The method for extracting and separating Ta and Na by using the solvent extraction system, hydrofluoric acidsulfuric acid-tributyl phoshate (TBP), was investigated. The extractability of fluotantalates and fluoniobiates from HF-H2SO4 solution into TBP was found to be functions of HF acidity, H2S04 acidity, TBP concentration, oxide concentration, organic solvent ratio, and extraction frequency. The results obtained can be summarized as follows: (1) The Ta percentage extraction and the Ta distribution ratio increased with the increase of H2SO4 acidity at a const HF acidity, but decreased with the increasing HF acidity at a constant H2SO4 acidity. They diminished with the decrease of TBP concentration. The Nb percentage extraction and the Nb distribution ratio augmented with increasing HF acidity, H2SO4 acidity, and TBP concentration. (2) In general, the separation coefficient was superior in lcw Hl acidity-low H2SO4 acidity, being inferior at high HF acidity-high H2SO4 acidity. 6) The HF-H2SO4-TBP system has larger extractability of Ta and Nb, particulary Nb, and is higher in purity the organic extract than the HF-112SO4-hexone system which is being used as the industrial extraction system for liquid-liquid extraction of Ta and Nb.

Separation and recovery of critical metal ions using ionic liquids

“…Similarly to MIBK extraction, tantalum can be separated from niobium in HF-H 2 SO 4 systems using TBP, however, when the concentrations of HNO 3 , HCl and H 2 SO 4 are high, the extraction efficiency of niobium decreases to levels too low for economic commercial extraction. Separation from other impurities however becomes more efficient for HF and HF-H 2 SO 4 systems [66].…”

Recovery of tantalum from synthetic sulfuric leach solutions by solvent extraction with phosphonate functionalized ionic liquids

“…Similar to an extraction with MIBK, the TBP extraction method from a mixture of hydrofluoric and sulfuric acids (Zhou et al, 2005) (HF-H2SO4 system) produces higher quantities of Ta than niobium (Nikolaev and Maiorov, 2007). The selective separation of niobium and tantalum from impurities (e.g., iron, manganese, silicon, titanium) was reported to be more efficient with TBP than with MIBK (Nishimura et al, 1964a;Nishimura et al, 1964b). Room-temperature ionic liquids (ILs), can be used as alternative diluents or extractants of volatile organic compounds in these extraction processes due to their nonflammability and nonvolatility (Brennecke and Maginn, 2001;Huddleston et al, 1998;Visser et al, 2001).…”

Hydrometallurgical Process for Tantalum Recovery from Epoxy-Coated Solid Electrolyte Tantalum Capacitors

“…Hence, in this study, the leaching process will be improved by combining the advantages of both methods. With respect to solvent extraction, several extractants, such as MIBK [17,18,19,20,21,22,23,24,25], TBP [19,26,27], CHO [19,22], OCL [28], and Alamine 336 [27,28,29,30,31,32] have been tested. Previous studies have indicated that Alamine 336 is a promising extractant for purifying tantalum in low HF concentrations [32].…”