To understand the behavior of molybdenum and tungsten extracted by tri-alkyl phosphine oxide(TRPO)from peroxide solution,the extraction mechanism was studied by slope method and Raman and FTIR spectroscopy.The empiric...To understand the behavior of molybdenum and tungsten extracted by tri-alkyl phosphine oxide(TRPO)from peroxide solution,the extraction mechanism was studied by slope method and Raman and FTIR spectroscopy.The empirical formulas of molybdenum and tungsten extraction distribution ratio(D_(Mo)and D_(W))as functions of equilibrium pH,TRPO concentration and temperature were obtained by establishing mathematical models.Furthermore,the reliability of the empirical formula was verified in the H^(+)-W-Mo-H_(2)O_(2) solution.The results indicate that the calculated values of D_(Mo)or D_(W)were consistent with the experimental values.The apparent extraction equilibrium constants of molybdenum and tungsten wereK_(Mo)^(app)=8.51×10^(3)(0.74≤pH_(e)≤1.7),K_(Mo)^(app)=99.89×10^(3)(1.7<pH_(e)≤4.62)andK_(W)^(app)=2.65×10^(3)(0.92<pH_(e)<2.16)at 20°C,respectively.The main extraction complex of molybdenum or tungsten was[H_(2)(Mo or W)_(2)O_(3)(O_(2))_(4)(H_(2)O)_(2)]·2TRPO.These empirical formulas can be used to analyze and estimate the extraction and separation of Mo and W from low molybdenum and tungsten concentration solutions.展开更多
基金support from the National Natural Science Foundation of China(No.51604304)。
文摘To understand the behavior of molybdenum and tungsten extracted by tri-alkyl phosphine oxide(TRPO)from peroxide solution,the extraction mechanism was studied by slope method and Raman and FTIR spectroscopy.The empirical formulas of molybdenum and tungsten extraction distribution ratio(D_(Mo)and D_(W))as functions of equilibrium pH,TRPO concentration and temperature were obtained by establishing mathematical models.Furthermore,the reliability of the empirical formula was verified in the H^(+)-W-Mo-H_(2)O_(2) solution.The results indicate that the calculated values of D_(Mo)or D_(W)were consistent with the experimental values.The apparent extraction equilibrium constants of molybdenum and tungsten wereK_(Mo)^(app)=8.51×10^(3)(0.74≤pH_(e)≤1.7),K_(Mo)^(app)=99.89×10^(3)(1.7<pH_(e)≤4.62)andK_(W)^(app)=2.65×10^(3)(0.92<pH_(e)<2.16)at 20°C,respectively.The main extraction complex of molybdenum or tungsten was[H_(2)(Mo or W)_(2)O_(3)(O_(2))_(4)(H_(2)O)_(2)]·2TRPO.These empirical formulas can be used to analyze and estimate the extraction and separation of Mo and W from low molybdenum and tungsten concentration solutions.
