This paper reviews the development course of separating rare earths with acid phosphorus extractants,including extraction chemistry(thermodynamics and kinetics), separation process and industrial application, the loss...This paper reviews the development course of separating rare earths with acid phosphorus extractants,including extraction chemistry(thermodynamics and kinetics), separation process and industrial application, the loss/degradation of extractants, etc.展开更多
For an AB/BC countercurrent extraction separation using organic feed, the conditions to have minimum amount of ex- tracting solvent （Smin） and minimum amount of scrubbing agent solution （Wmin） were discussed, and ...For an AB/BC countercurrent extraction separation using organic feed, the conditions to have minimum amount of ex- tracting solvent （Smin） and minimum amount of scrubbing agent solution （Wmin） were discussed, and the formulae of both Sroin and Wmin were deduced. It was shown that only when the ratio of flowrate of central component B leaving aqueous outlet to that leaving organic outlet took a certain optimal value, the AB/BC separation could have Smin as well as Wmin, and this optimal ratio was decided by the separation factors between the three components but independent of feed composition. Smin was only relative to the separation factor of A/C pair but regardless of the separation factors of other pairs as well as feed composition, whereas Wmin was determined by the separation factors between the components together with feed composition. Meanwhile it was also found that the organic stream out of feed stage was same composition as the initial organic feed when the separation system was given by the two minimum amounts and its steady state was achieved. Finally the results above were used to design a LuYb/YbTm separation case and the stage-wise compositions of each component in both the organic and the aqueous phase at steady state were given by computer simulation.展开更多
In this article, the recent progress made by Peking University is briefly introduced. Based on Theory of Countercurrent Extraction established by Prof. Guangxian Xu, the static equilibrium and dynamic process for two-...In this article, the recent progress made by Peking University is briefly introduced. Based on Theory of Countercurrent Extraction established by Prof. Guangxian Xu, the static equilibrium and dynamic process for two- and three-outlet countercurrent extractions, and designed the optimized parameters for the real cascades to separate different rare earth minerals, which can be scaled-up to the industrial process without any further experimental verification were systematically investigated. In order to stabilize the quality of products and improve the capability of automation for extraction process, we have also established an (()^(241)Am) stimulated X-ray fluorescent energy dispersive method to detect the elemental composition in both organic and aqueous phases, which can be used as an on-line analysis method in practice. Furthermore, the expert system and the control software with open- and close-loop models have been set up. Combined with the detected data from on-line analysis, the flow-rates of extracting, feeding, scrubbing and stripping solutions can be (controlled) in an optimum status for the industrial cascades. In addition, we have developed a new multi-input and multi-output countercurrent extraction process for separating multi-component rare earth mixture with lower chemical cost and pollution.展开更多
During the last decade, China rare earth （RE） industry has made significant progress and become one of the most important producers in the world. In this paper, the recent developments in both fundamental research a...During the last decade, China rare earth （RE） industry has made significant progress and become one of the most important producers in the world. In this paper, the recent developments in both fundamental research and industrial application are briefly reviewed： （1） the development and application of Theory of Countercurrent Extraction, （2） the novel solvent extraction process and its application in industry for separating heavy rare earth elements （Tm, Yb, Lu）, yttrium （Y）, and scandium （Sc）, （3） the on-line analysis and automatic control of countercurrent extraction, （4） the eco-friendly process for RE/Th separation of bastnasite in Sichuan Province and electrochemical process for Eu/RE separation, and （5） the optimized flowcharts for typical rare earth minerals in China.展开更多
基金Project supported by the National Basic Research Program of China(973 Program,2006CB403302)
文摘This paper reviews the development course of separating rare earths with acid phosphorus extractants,including extraction chemistry(thermodynamics and kinetics), separation process and industrial application, the loss/degradation of extractants, etc.
基金Project supported by the 973 Program-Major Project of Chinese National Programs for Fundamental Research and Development(2012CBA01200)
文摘For an AB/BC countercurrent extraction separation using organic feed, the conditions to have minimum amount of ex- tracting solvent （Smin） and minimum amount of scrubbing agent solution （Wmin） were discussed, and the formulae of both Sroin and Wmin were deduced. It was shown that only when the ratio of flowrate of central component B leaving aqueous outlet to that leaving organic outlet took a certain optimal value, the AB/BC separation could have Smin as well as Wmin, and this optimal ratio was decided by the separation factors between the three components but independent of feed composition. Smin was only relative to the separation factor of A/C pair but regardless of the separation factors of other pairs as well as feed composition, whereas Wmin was determined by the separation factors between the components together with feed composition. Meanwhile it was also found that the organic stream out of feed stage was same composition as the initial organic feed when the separation system was given by the two minimum amounts and its steady state was achieved. Finally the results above were used to design a LuYb/YbTm separation case and the stage-wise compositions of each component in both the organic and the aqueous phase at steady state were given by computer simulation.
文摘In this article, the recent progress made by Peking University is briefly introduced. Based on Theory of Countercurrent Extraction established by Prof. Guangxian Xu, the static equilibrium and dynamic process for two- and three-outlet countercurrent extractions, and designed the optimized parameters for the real cascades to separate different rare earth minerals, which can be scaled-up to the industrial process without any further experimental verification were systematically investigated. In order to stabilize the quality of products and improve the capability of automation for extraction process, we have also established an (()^(241)Am) stimulated X-ray fluorescent energy dispersive method to detect the elemental composition in both organic and aqueous phases, which can be used as an on-line analysis method in practice. Furthermore, the expert system and the control software with open- and close-loop models have been set up. Combined with the detected data from on-line analysis, the flow-rates of extracting, feeding, scrubbing and stripping solutions can be (controlled) in an optimum status for the industrial cascades. In addition, we have developed a new multi-input and multi-output countercurrent extraction process for separating multi-component rare earth mixture with lower chemical cost and pollution.
基金Supported by the Ministry of Science and Technology of China (Nos.G1998061301 and 2006CB601100), the National Natural ScienceFoundation of China (Nos. 20371003 and 20221101), and FounderFoundation of Peking University
文摘During the last decade, China rare earth （RE） industry has made significant progress and become one of the most important producers in the world. In this paper, the recent developments in both fundamental research and industrial application are briefly reviewed： （1） the development and application of Theory of Countercurrent Extraction, （2） the novel solvent extraction process and its application in industry for separating heavy rare earth elements （Tm, Yb, Lu）, yttrium （Y）, and scandium （Sc）, （3） the on-line analysis and automatic control of countercurrent extraction, （4） the eco-friendly process for RE/Th separation of bastnasite in Sichuan Province and electrochemical process for Eu/RE separation, and （5） the optimized flowcharts for typical rare earth minerals in China.
