Abstract
The effects of feeding location on crystals size and distribution, precipitation percentage of Pu(IV) oxalate were investigated in a vortex continuous precipitator when the apparent average residence time was 25 min at 50 °C. The results showed that when oxalic acid was into the free vortex zone and Pu(IV) nitrate solution was into the forced vortex one, the VMD of the particles near the outlet of the precipitator increased from 36.8 ± 1.2 µm to 45.8 ± 2.1 µm, the precipitation percentage of Pu(IV) oxalate from 97.90% ± 1.0–99.79% ± 0.05%, compared with another feeding location, both oxalic acid and Pu(IV) nitrate solution into the forced vortex zone. The two feeding methods could both prevent Pu(IV) oxalate nuclei contacting the inner wall of the precipitator during nucleation. The results showed agglomeration happened during crystals growth even under stirring. Both local supersaturations and agglomeration decided particles size distribution and the average size of Pu(IV) oxalate.
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Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
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Research funding: None declared.
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Conflict of interest statement: The authors declare no conflicts of interest regarding this article.
References
1. Martella, L. L., Saba, M. T., Campbell, G. K. Laboratory-Scale Evaluations of Alternative Plutonium Precipitation Methods; Rockwell International Corp.: Golden, CO (USA). Rocky Flats Plant, 1984.10.2172/5318991Search in Google Scholar
2. Rankin, D. T., Burney, G. A. Particle Size of 238PuO2 Obtained by Oxalate Precipitation and Calcination; Du Pont de Nemours (EI) and Co.: Aiken, SC (USA). Savannah River Lab, 1974.Search in Google Scholar
3. Grandjean, S., Arab-Chapelet, B. The oxalic process for the conversion of Pu into PuO2 and the coconversion of U and Pu into (U, Pu)O2. Global 2009, 2009, 89–90.Search in Google Scholar
4. Crowder, M., Pierce, R. Small-Scale Testing of Plutonium (IV) Oxalate Precipitation and Calcination to Plutonium Oxide to Support the MOX Feed Mission; SRS: Washington, DC, 2012.10.2172/1044791Search in Google Scholar
5. Poncelet, F. J., Moulin, J. P., Hubert, N. Continuous precipitation and filtration. In A Process Technology for Liquid Waste Management. WM’01 Conference, February 25-March 1, Tucson, AZ, 2001.Search in Google Scholar
6. Drain, F., Gillet, B., Bertolotti, G. The oxalate process: the only way for plutonium conversion. GLOBAL’99, Jackson Hole, Wyoming, USA. August 29–September 3, 1999, 099.Search in Google Scholar
7. Bertrand, M., Plasari, E., Lebaigue, O., Baron, P., Lamarque, N., Ducros, F. Hybrid LES-multizonal modelling of the uranium oxalate precipitation. Chem. Eng. Sci. 2012, 77, 95–104.10.1016/j.ces.2012.03.019Search in Google Scholar
8. Hoytet, R. C., Bouse, D. G. Control of Particle Size and Structure during Plutonium Oxalate Precipitation, Vol. 49; Dans American Nuclear Society Transactions: Boston, Massachusetts, 1985.Search in Google Scholar
9. Facer, J. F.Jr., Harmon, K. M., Harmon, K. M. Precipitation of Plutonium (IV) Oxalate; General Electric Co. Hanford Atomic Products Operation: Richland, Wash, 1954; pp. 3–42.10.2172/4634035Search in Google Scholar
10. Hoyt, R. C., Bouse, D. G. Control of Particle Size and Structure during Plutonium Oxalate Precipitation, Vol. 49; Dans American Nuclear Society Transactions: Boston, Massachusetts, 1985.Search in Google Scholar
11. Bertrand, M., Baron, P., Plasari, E. Modelling of actinide precipitation processes. In Proceedings of GLOBAL 2011, Makuhari Messe in the Chiba province of Japan, Organaized by Atomic Energy Society of Japan Co-organized by Japan Atomic Energy Agency Dec; Atomic Energy Society of Japan, 2011; p. 392550.Search in Google Scholar
12. Nagata, S., Yoshioka, N., Yokoyama, T. Studies on the power requirement of mixing impellers. Mem. Fac. Eng. Kyoto Univ. 1955, 17, 175–185.Search in Google Scholar
13. Bertrand, M., Parmentier, D., Lebaigue, O., Plasari, E., Ducros, F. Mixing study in an unbaffled stirred precipitator using LES modelling. Int. J. Chem. Eng., 2012, 1–11. Hindawi Publishing Corporation.10.1155/2012/450491Search in Google Scholar
14. Bertrand, M., Baron, P., Plasari, E., Gaillard, J. P., Lebaigue, O., Ducros, F. Modelling of actinide precipitation processes. Proc. GLOBAL 2011, 392550.Search in Google Scholar
15. Bertrand-Andrieu, M., Plasari1, E., Baron, P. Determination of nucleation and crystal growth kinetics in hostile environment – application to the tetravalent uranium oxalate U(C2O4)2·6H2O. Can. J. Chem. Eng. 2004, 82, 930–931.10.1002/cjce.5450820508Search in Google Scholar
16. Zoppé, B., Lebaigue, O., Ducros, F., Bertrand, M. Hydrodynamic modelling of flow patterns in a vortex reactor -application to the mixing study. In ATALANTE 2008 Montpellier (France), May 19–22; Corum: Montpellier, France, 2008; pp. 3–24.Search in Google Scholar
17. Lallemana, S., Bertranda, M., Gaillarda, J. P. Scale-up study of agglomeration during oxalic precipitation innuclear industry. Procedia Chem. 2012, 7, 493–498.10.1016/j.proche.2012.10.075Search in Google Scholar
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