Solvent extraction centrifugal contactor

It is a practical fact that most industrial solvent extractions are carried out under nonequilibrium conditions, however close the approach may be for example, centrifugal contactor-separators (Chapter 9) rarely operate at distribution equilibrium. An interesting possibility is to expand this into extractions further from equilibrium, if the kinetics of the desired and nondesired products are different. Such operations offer a real technlogical challenge. 

Often the products of nuclear reactions have very short half-lives. This is especially true for the heaviest elements obtained by bombardment of heavy targets with heavy ions. To identify and characterize such short-lived nuclides, fast separations are required solvent extraction techniques are well suited to provide the required fast separations. For example, the SISAK method [68] has been successfully used in conjunction with in-line gas jet separators at heavy ion accelerators to identify short half-life actinide isotopes produced by collision of heavy atoms. The Sisak method involves use of centrifugal contactors, with phase residence times as low as tenths of a second, in conjunction with in-line radiometric detection equipment. 

One attempt to improve the situation has been successful for small to moderate scale operations where high purity is required—namely, the Podbielniak centrifugal counter-current contactor and separator, which dominates the solvent extraction phase of penicillin manufacture. 

Jenkins, J.A., Mills, A.L., Thompson, P.J., Jubin, R.T. 1993. Performance of centrifugal contactors on uranium and plutonium active PUREX flowsheets. In Solvent Extraction in the Process Industries ISEC 93, York, UK, September 16-21. Logsdail, D.H., Slater, M.J. Eds. Elsevier Applied Science, London and New York. 

Modolo, G., Asp, H., Vijgen, H. et al. 2008. Demonstration of a TODGA-based continuous counter-current extraction process for the partitioning of actinides from a simulated PUREX raffinate, PartB Centrifugal contactor runs. Solvent Extr. Ion Exch. 26 (1) 62-76. 

Bilancia, G., Facchini, A., Ferrando, M. et al. 2005. Selective actinide extraction with a tri-synergistic mixture using a centrifugal contactor battery. Solvent Extr. Ion Exch. 23 (6) 773-780. 

Nakahara, M., Sano, Y., Koma, Y., Kamiya, M., Shibata, A., Koizumi, T., Koyama, T. 2007. Separation of actinide elements by solvent extraction using centrifugal contactors in the NEXT process. Journal of Nuclear Science and Technology 44(3) 373-381. 

Design Principles and Applications of Centrifugal Contactors for Solvent Extraction... 

In this chapter, Section 10.2 gives an overview of the operation of the Argonne centrifugal contactor. Section 10.3 focuses on the design principles for this contactor. Section 10.4 discusses the worldwide applications of this contactor to solvent-extraction processes of interest to the nuclear and other industries. Comparisons with other types of contactors are made throughout the text, and a separate section is devoted to them in Section 10.4. However, because of their widespread use and the author s particular experience with them, the ANL contactor and its variations remain the primary focus. 

A solvent-extraction flowsheet is broken down into sections such as extraction, scrub, and strip. For each section, one or more component in a process fluid must be moved from one phase to the other phase with a specified degree of completeness. The first design problem is to determine the number of stages for each section to accomplish the required component transfer. With the well-defined stages of the centrifugal contactor, the following extraction factor (E) can be used to estimate the number of stages required ... 

The INET annular centrifugal contactors are being used to partition high-level liquid waste so that the back end of the nuclear fuel cycle can be simplified. In particular, the TRPO process has been developed at INET for this application (Song, 2000), where TRPO is the extractant in the process solvent. Also known as Cyanex 923, TRPO is a trialkyl phosphine oxide that is made commercially by Cytec Industries (formerly American Cyanamid). It has a high affinity for the actinides. Further... 

Birdwell, Jr., J. F., and K. K. Anderson. 2001. Evaluation of 5-cm Centrifugal Contactor Hydraulic and Mass Transfer Performance for Caustic-side Solvent Extraction of Cesium. Oak Ridge National Laboratory Report ORNL/TM-2001/137, Oak Ridge, TN. 

Bergeonneau, P., C. Jaonen, M. Germain, and A. Bathellier. 1979. Uranium, Neptunium, and Plutonium Kinetics of Extraction by Tributylphosphate and Trilaurylamine in a Centrifugal Contactor. Proceedings of International Solvent Extraction Conference (ISEC 77), September 9-16, 1977, Toronto, Canada, vol. 2, 612-619. 

Duan, W., X. Zhou, and J. Zhou. 2006. Extraction of Caffeine with Annular Centrifugal Contactors. Solvent Extr. IonExch. 24(2), 251-259. 

Leonard, R. A., D. B. Chamberlain, and C. Conner. 1997. Centrifugal Contactors for Laboratory-scale Solvent Extraction tests. Sep. Sci. Technol. 32(1-4), 193-210. 

Leonard, R. A., C. Conner, M. W. Liberatore, et al. 1999. Evaluation of an Alkaline-Side Solvent Extraction Process for Cesium Removal from SRS Tank Waste Using Laboratory-Scale Centrifugal Contactors. Argonne National Laboratory Report ANL-99/14, Argonne, IL. 

Rivalier, P. and J-Y. Lanoe. 2000. Development of a New Miniature Short-residence-time Annular Centrifugal Solvent Extraction Contactor for Tests of Process Flowsheets in Hot Cells. ATALANTE 2000, October 24—26, Avignon, France. 

Rivalier, P., F. Gandi, and J. Duhamet. 2004. Development of a New Annular Centrifugal Solvent Extraction Contactor. ATALANTE 2004, June 21-24, Nimes, France. 

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