SOLVATION EXTRACTION OF TRANSITIONMETALS Cr, Mo, W AND V BY AMINES
Yu Shuqiu;Chen Jiayong Chen Chiayung Institute of Chemical Metallurgy; Academia Sinica; Beijing
Cite this article:
Yu Shuqiu;Chen Jiayong Chen Chiayung Institute of Chemical Metallurgy; Academia Sinica; Beijing. SOLVATION EXTRACTION OF TRANSITIONMETALS Cr, Mo, W AND V BY AMINES. Acta Metall Sin, 1982, 18(2): 187-200.
Abstract Metals such as Cr(Ⅵ),Mo(Ⅵ),W(Ⅵ) and V(Ⅴ) can be extracted by am- ines from nearly neutral aqueous solutions.The mechanism of extraction has found to be by solvation with molecular association through hydrogen bonds.The number of active hydrogen atoms attached to nitrogen atom of different classes of amine determine their effectiveness in extraction of metals by solvation.Primary am- ines with two hydrogen atoms attached to each nitrogen atom are the most effec- tive extractants in comparison with secondary and tertiary amines.Results obtained from metals extraction with amines by the present reported solvation mechanism are quite different from those obtained by the widely studied anion exchange mechanism. The oxo and hydroxo complexes of transition metals such as Cr,Mo,W and V in aqueous solutions form different types of isopolyanion at different solution pH.The electric charge density or specific charge of different isopolyanions can be used to predict the relative tendency of these species to be extracted by the amines through solvation mechanism.Experimental results confirm the prediction and indicate that by using amines as solvation extractant new processes can be developed for metal extraction and separation.