Solvent extraction and selective separation of vanadium (V) from an acidic sulfate solution using 2-Ethyl-1-Hexanol

- 2-ethyl-1-hexanol is employed as a novel solvent to extract the pentavalent vanadium from the sulfate media.
- Effect of the different process ariables such as temperature, pH etc on the extraction of V(V) is explored.
- 2-ethyl-1-hexanol is found to be a selective extractant for the separation of V(V) over Fe(III), U(VI), Si(IV), and Al(III).
- An effective method for the stripping of V(V) from the organic phase and the precipitation of vanadium compound is proposed.

In this work, 2-ethyl-1-hexanol, a long chain alcohol, is used to extract pentavalent vanadium V(V) from both sodium metavanadate solution and a synthetic leach liquor. At first, effects of process parameters on the extraction of V(V) from a solution free from the other metals are examined and discussed. The maximum extraction yield has been achieved at initial pH (pH0) about 2.0. Moreover, the influences of the concentration of extracting reagent, initial vanadium concentration, and organic/aqueous (O/A) phase ratio on the extraction are investigated. Subsequently, recovery of V(V) from a synthetic leach solution in the presence of Fe(III), U(VI), Si(IV), and Al(III) was explored. Under the extraction conditions of initial pH of 1.9, 2-ethyl-1-hexanol concentration of 70 v/v%, extraction temperature of 60 °C, and phase ratio (O/A) of 2/1; about 93% of V(V) was extracted while the extraction of the other coexisting metals was lower than 8%. The present results showed that 2-ethyl-1-hexanol is a suitable solvent for the selective separation of V(V) from the acidic sulfate solutions. Moreover, a method for the stripping and precipitation of the V(V) compound was proposed to achieve the complete recovery of vanadium. The presented method led to the selective stripping of V(V) from the organic phase and its complete precipitation in the form of ammonium metavanadate.