SOLVATION EXTRACTION OF W FROM DILUTE TUNGSTATE SOLUTIONS BY AMINES.

Solvation extraction of W(VI) from dilute tungstate solutions by dilute organic solutions of amines was studied. It has been found that the mechanisms of solvation extraction of W from dilute and concentrated tungstate solutions are different. The W compound extracted into the organic phase from concentrated tungstate solutions by primary amines is seen to be normal tungstic acid (H//2WO//4), as determined by earlier work. The present work indicates, however, that the W(VI) compound or complex extracted by a primary amine from dilute tungstate solutions is some other tungsten compound or complex, such as WO//2(OH)//2. The hydrophilic complexes were formed first during solvation extraction from dilute W solutions. The complexes are then dehydrated slowly and then transferred into the organic phase. Use of tertiary amines as solvation extractant for W was also investigated.