Reduction - Complex System Of Extraction Separation Of Tungsten Molybdenum Applied Basic Research

Along with the increasing consumption of wolframites resources，scheelitewith high contents of molybdenum and Secondary resources of tungsten andmolybdenum become to be important raw materials in tungsten industry。whichtherefore results in technical development trend of high efficient separation oftungsten and molybdenum。In the study of Projects of National Natural ScienceFoundation，we found that the solubility of wolframic acid and molybic acidincreased as a weak reductant of oxalic acid complexed with wolframic andmolybic radical，And a strong reductant of sulfite not only complexed withwolframic but also with molybic by complexation-reduction reaction。In this study，a program of W-Mo extraction separation in reduction-complexation system wasproposed and the dynamics of W and Mo extracted by N235in oxalic acid systemand sodium sulfite system was investigated, which provides theoretical basis fornew technology development。The main contents are as follows:（1） Dynamics of tungsten extracted by N235in oxalic acid.The method of invariable interface was employed，the experimental resultsindicated that the apparent activation energy was E-1a=17.40kJ· molas therotate-speed less than120r/min and the mechanism of the extracting belong todiffusion control， the extraction rate equation was expressed as R（WO₃）=k[R₃N]^0.94[WO₃]⁰.86[H₂C₂O₄]^0.124]0.（2） Dynamics of molybdenum extracted by N235in sodium sulfiteThe method of invariable interface was employed，the experimental resultsindicated that the apparent activation energy was E_a=18.38kJ· mol^-1as therotate-speed less than120r/min and the mechanism of the extracting belong todiffusion control， the extraction rate equation was expressed as R（Mo）=k[R₃N]^0.29[Mo]^0.28[Na₂SO₃]^-0.28[H⁺]^-1.36（3） Determination of W-Mo separation coefficient extracted by N235inoxalic acid solutionThe experimental results indicates that the composition of organic phase was：25%N235+15%n-octanol，Concentrations of tungsten trioxide and molybdenumwere50g/L and10g/L respectively，The solution pH was1.5，Mole dosage ofoxalic acid was twice as much as WO₃，Mo was extracted primarily by N235frommolybdenum-oxalic acid complexation ion and the separation coefficient βMo/WO₃was17.63。 （4） Exploration and research of W-Mo separation extracted by N235insodium sulfite solution.The experimental results indicates that portion of Mo existed in form ofnonionic colloidal macromolecule in Mo-sodium sulfite solution which can beadsorbed by particulate matter A；W existed in form of ion still in W-sodium sulfitesolution；the existence form of W and Mo were complicated in W-Mo-sodiumsulfite solution，W and Mo were coextracted obviously.