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
The numerical calculations for Am multistage fractional extraction by trialkyl phosphine oxide (TRPO) were verified by a hot test. 1750L/t-U high level waste (HLW) was used as the feed to the TRPO process. The analysi...The numerical calculations for Am multistage fractional extraction by trialkyl phosphine oxide (TRPO) were verified by a hot test. 1750L/t-U high level waste (HLW) was used as the feed to the TRPO process. The analysis used the simple objective function to minimize the total waste content in the TRPO process streams. Some process parameters were optimized after other parameters were selected. The optimal process parameters for Am extraction by TRPO are: 10 stages for extraction and 2 stages for scrubbing; a flow rate ratio of 0.931 for extraction and 4.42 for scrubbing; nitric acid concentration of 1.35mol/L for the feed and 0.5mol/L for the scrubbing solution. Finally, the nitric acid and Am concentration profiles in the optimal TRPO extraction process are given.展开更多
目的建立一种采用超滤-络合萃取技术制备甘草酸的工艺。方法考察pH值(p H 4～8)对超滤液中甘草酸萃取率的影响;采用正交试验优选络合萃取甘草酸的工艺条件;通过考察反萃取剂种类及浓度,确定甘草酸的反萃取工艺条件。结果所得甘草酸最佳...目的建立一种采用超滤-络合萃取技术制备甘草酸的工艺。方法考察pH值(p H 4～8)对超滤液中甘草酸萃取率的影响;采用正交试验优选络合萃取甘草酸的工艺条件;通过考察反萃取剂种类及浓度,确定甘草酸的反萃取工艺条件。结果所得甘草酸最佳络合萃取工艺条件为超滤液pH值应调至2、萃取剂为三烷基氧化膦(TRPO)-磺化煤油(5∶95)、有机相与水相体积比为1∶1,甘草酸平均萃取率达到99.2%。甘草酸最佳反萃取工艺条件为22.5 mmol/L NaOH水溶液为反萃取剂、有机相与反萃取剂体积比1∶1,甘草酸单次反萃取率达到98.8%,甘草酸总转移率为98.1%。结论超滤-络合萃取技术可作为甘草酸制备的一种新工艺。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.
基金the Major Research Project of the Ninth-Five Plan(1996 2 0 0 0 ) of China!(No:96 - A18- 0 2 - 0 1)
文摘The numerical calculations for Am multistage fractional extraction by trialkyl phosphine oxide (TRPO) were verified by a hot test. 1750L/t-U high level waste (HLW) was used as the feed to the TRPO process. The analysis used the simple objective function to minimize the total waste content in the TRPO process streams. Some process parameters were optimized after other parameters were selected. The optimal process parameters for Am extraction by TRPO are: 10 stages for extraction and 2 stages for scrubbing; a flow rate ratio of 0.931 for extraction and 4.42 for scrubbing; nitric acid concentration of 1.35mol/L for the feed and 0.5mol/L for the scrubbing solution. Finally, the nitric acid and Am concentration profiles in the optimal TRPO extraction process are given.
文摘目的建立一种采用超滤-络合萃取技术制备甘草酸的工艺。方法考察pH值(p H 4～8)对超滤液中甘草酸萃取率的影响;采用正交试验优选络合萃取甘草酸的工艺条件;通过考察反萃取剂种类及浓度,确定甘草酸的反萃取工艺条件。结果所得甘草酸最佳络合萃取工艺条件为超滤液pH值应调至2、萃取剂为三烷基氧化膦(TRPO)-磺化煤油(5∶95)、有机相与水相体积比为1∶1,甘草酸平均萃取率达到99.2%。甘草酸最佳反萃取工艺条件为22.5 mmol/L NaOH水溶液为反萃取剂、有机相与反萃取剂体积比1∶1,甘草酸单次反萃取率达到98.8%,甘草酸总转移率为98.1%。结论超滤-络合萃取技术可作为甘草酸制备的一种新工艺。
