Method for removing molybdenum from tungstate solutions by solvent extraction

摘要

Disclosed is a process for removing molybdenum values from aqueous solutions containing tungsten values comprising sulfidizing said solution to an extent sufficient to convert substantially all of the molybdenum values to a thiomolybdate species, said sulfidizing being substantially less than the extent necessary to convert substantially all of said tungsten values to a thiotungstate species and contacting the resulting solution containing the thiomolybdate complex ion with a suitable amount of an organic extractant for a sufficient period of time to preferentially extract the thiomolybdate complex ion into the organic extractant, said organic extractant comprising an aromatic organic solvent and a quaternary ammonium compound of the formula R.sub.3 (CH.sub. 3)N.sup.+ A.sup.-, wherein R is an alkyl group having from about 8 to 10 carbon atoms and A is an anion derived from a mineral acid.