SOLVENT EXTRACTION OF VANADIUM (V) FROM AQUEOUS SOLUTIONS BY PRIMARY AMINES

Vanadium (Ⅴ) can be quantitatively extracted by primary amines from nearly neutralchromium (Ⅵ) containing aqueous solutions Under similar conditions wtth equilibriumaqueous phase pH above 7, no vanadium can practically be extracted by tertiary amines whileextraction by secondary amines is only about 25--30%. The quantitative extraction of vana-dium from aqueous solutions containing no chromium (Ⅵ) can be obtained by adding acidto the extent that the ratio of gram equivalents of H~+ added to the gram atoms of vanadiumin the apueous solution is equal to one or slightly higher. The mechanism of axtraction isbelieved to be solvation with molecular association between primary amines and tetravanadicacids through hydrogen bonding.