L. A. Safonova

Extraction of tantalum, niobium, and antimony fluorides

This report deals with the effects of the HF and H2SO4 concentrations and the organic-to-aqueous phase ratio Vorg: Vaq on the distribution of Ta, Nb, and Sb in their extraction with tributyl phosphate and n-octanol from model solutions that are similar in composition to those obtained in columbite-tantalite processing. The recovery of these elements decreases in the order Ta ≫ Sb ≥ Nb. Process conditions for efficient separation of Ta from Nb and Sb have been found.

Extraction of phosphorus(V), molybdenum(VI), and tungsten(VI) from fluoride solutions

The influence of titanim(IV) and silicon(IV) on the extraction of phosphorus(V), molybdenum (VI), and tungsten(VI) fluoride complexes by tributyl phosphate was studied.

Extraction of antimony and niobium with tributyl phosphate from fluoride-ammonium solutions

The purification of niobium from antimony impurity via extraction with tributyl phosphate from solutions of the HF + NH4F mixture has been studied. It has been established that at an HF + NH4F content equal to 7–16 mol/L and an NH4F concentration of 30% in the mixture, Sb extraction hardly changes (70–80% for one stage), and Nb coextraction abruptly decreases to values of less than 0.5%.

Purification of niobium from antimony by the extraction with tributylphosphate

The effect of the concentrations of HF and H2SO4 and organic-to-aqueous phase ratio Vo : Vaq on the distribution of Sb and Nb in their extraction with tributyl phosphate has been studied. It has been determined that, under the best conditions (HFfree 150 g/L, H2SO4 100 g/L, and Vo : Vaq = 0.3 : 1), and the extraction of Sb within one step is 72%, which is followed by the coextraction of Nb at 25%. The flow diagram of extraction and separation of Ta, Sb, and Nb from model solutions, which are close in composition to the reprocessed tantalite-columbites, has been suggested.

Extraction of molybdenum(VI) from fluoride niobium-tantalum solutions with a high content of titanium(IV)

Distribution of molybdenum(VI) (0.05 M) upon extraction with tributyl phosphate from fl uoride solutions with a content of titanium(IV), niobium(V), and tantalum(V) of up to 3.0, 0.7, and 0.7 M, respectively, was studied.

Investigation of conditions for extraction separation of thorium from calcium and lanthanum

Thorium extraction with tributylphosphate from artificial solutions close in structure to the obtained muriatic technology of perofskite has been studied. It has been shown that the application of tributylphosphate with the addition of dodecane serves to decrease the coextraction of Ca and La to values of ∼6 and 1.2–1.6%, respectively.

Study of conditions of vanadium(IV, V) leaching from ash

Leaching of vanadium(IV, V) with water and a NaOH solution from ash produced in black oil combustion was studied.