モリブデンとバナジウムの溶媒抽出分離

抄録

The separation of Mo and V in a leach solution by solvent extraction using a basic extractant was studied for artificial solutions as well as industrial leach solutions containing both Mo(VI) and V(V), and a selective reduction-solvent extraction method, originally developed by the present authors, was found to be useful for this purpose. The principal results are as follows:
(1) Although Mo(VI) is stable in aqueous acidic solutions, V(V) is readily reduced to V(IV), which is less sensitive to solvent extraction. Solvent extraction of reduced aqueous solution resulted in a satisfactory separation of Mo from V. Although different acids or different reducing agents resulted in slightly different results, no interinsic difference in extraction characteristics was detected.
(2) Mo(VI) and V(V), both extracted in an organic phase, can be separated by stripping with artificial aqueous phase containing suitable reducing agents such as SO₂ or its derivatives. The use of multi-stage stripping technology may allow complete separation.
(3) When the solvent extraction of leach solution containing both Mo(VI) and V(V) was performed in an autoclave under SO₂ pressure, the transfer of Mo(VI) alone into an organic phase occurred. The separation of Mo from V was sufficient.
(4) The selective reduction-solvent extraction method was applied to the solution derived from the salting-out process to separate Mo and V. The Mo product (H₂MoO₄) and V products (NH₄VO₃ and VO(OH)₂) produced from each separated solution were found to be substantially purer than those obtained by current methods.