Examination of Extraction of Vanadium(V) by Trioctylamine from Sulfuric Solutions

Abstract

The effect of different factors, such as pH of the medium (1.5 Ͻ pH Ͻ 4.0; 1 ϫ 10 -4 mol·L -1 Ͻ [SO 42-] Ͻ 1 ϫ 10 -1 mol·L -1 ), the concentration of extracting agent, temperature and the type of the solvent, on the extraction of vanadium(V) by trioctylamine was studied. It was shown that the extraction of vanadium(V) by trioctylamine at 25 Ϯ 0.5°C takes place in the pH range 2.0-3.5 and the extracting complex contains decavanadate anion H 2 V 10 O 28 4and four molecules of the extracting agent. This allows the reaction of vanadium(V) extraction by trioctylamine to be described by the following equation: 2(

Extraction-Chromogenic Systems for Vanadium(V) Based on Azo Dyes and Xylometazoline Hydrochloride

“…This equation is based on information concerning the state of V(V) 54,55 and ADRs (TAR 56 and MTAR 57 ) at the reaction conditions. Although ADRs can stabilize low oxidation state metal centers, 58,59 V(V) is not reduced in their presence.…”

Extraction Recovery of Vanadium(V) by Amines

“…Its application for the extraction of vanadium (IV) also involves some difficulties. In the process solutions, vanadium has usually the oxidation state five and for its extraction vibrations of free vanadium-oxygen bonds at 960 cm −1 and bridge bonds V-O-V at 750 and 590 cm −1 , which, as shown above [5], are related to vibrations of V-O bonds in decavanadate anion. We did not find any bands typical of vanadium (IV) oxocation in the region of 1000 nm [6].…”