Cesium recovery

Tsuda, T., Hussey, G. L., Luo, H. M., Dai, S., Recovery of cesium extracted from simulated tank waste with an ionic liquid Water and oxygen effects, /. Electrochem. Soc., 153, D171-D176, 2006. 

Fig. II. Effects on rate and catalyst stability of using sulfolane-tetraglyme mixtures as solvent ( ) methanol ( ) ethylene glycol ( ) rhodium recovery. Reaction conditions 75 ml solvent, 3 mmol Rh, 0.65 mmol cesium benzoate, 544 atm, H2/CO = 1, 240 C, 4 hr (94).

An efficient synthesis of hexafluorobut-2-yne25,26 combined the knowledge that hexafluorocy-clobutene thermally rearranges to hexafluorobuta-1,3-diene (vide supra) and that cesium or potassium fluoride isomerize dienes to alkynes (see Section 5.1.2.3.). Thus, when hexafluoro-cyclobutene is passed over cesium or potassium fluoride at 590-600 C, hexafluorobut-2-yne is obtained in yields up to 90%, with 95% recovery of material. 

After acquisition of experimental data, flowsheet calculations were carried out. A theoretical recovery of cesium was fixed at 99.99%. Hydraulic tests and chemical transfer tests were first carried out with centrifugal contactors, then with pulsed columns, first on simulated effluents and then on actual effluents. 

In the tests carried out in centrifugal extractors, the extraction and recovery of cesium higher than 99.99% were obtained on simulated effluents, with a very good coherence between calculated flowsheets and experimental results.102 Tests confirmed the feasibility of the implementation of the cesium process in pulsed columns, the latter representing the most adapted contactors for the industrial implementation to overcome the drawback due to the presence of solid matter in waste to be treated. 

Filippov, E.A., Dzekun, E.G., Nardova, A.K. Mamakin, I.V., Gelis, V.M., Mityutin, V.V. Application of crown-ethers and ferrocyanide-based inorganic materials for cesium and strontium recovery from high-level radioactive wastes. In Proc. Symp. Waste Management, Tucson, AZ, Vol. 2, 1992, pp. 1021-1024. 

Filippov, E. A., Dzekun, E. G., Nardova, A. K., Mamakin, I. V., Gelis, V. M., and Milyutin, V. V. Application of Crown Ethers and Ferrocyanide-Based Inorganic Material for Cesium and Strontium Recovery from High-Level Radioactive Wastes, Proc. Waste Management 92, Tucson, Arizona, U.S.A., Mar. 1-5, 1992, pp. 1021-1025. 

Each compound was soaked for 1 hr in 38% (wt/v) HC1 followed by soaking in 55% (wt/v) HF for 1 hr. Each was then rinsed exhaustively with water and dried under vacuum at room temperature. In a separate experiment each of the model compounds were exposed to a solution of cesium chloride. After sufficient exposure each compound was recovered and washed with copious quantities of distilled water. The percentage recovery, the melting point and spectroscopic data such as FTIR, proton and carbon-13 NMR were recorded. 

Modifications to this process can be made to effect recovery of neptunium, americium, curium, californium, strontium, cesium, technetium, and other nuclides. The efficient production of specific transuranic products requires consideration of the irradiation cycle in the reactor and separation of intermediate products for further irradiation. 

Scrap steel is extensively recycled without incident, as mentioned in the introductory comments. However, before it is accepted into a steel remelting yard it should be checked for any stray radioactive material. Of the 21 known accidents of steel contamination with cobalt 60, cesium 137, or other radioactive materials, eight occurred in the 1992-1993 period [45]. Checking is simple and inexpensive compared with the potentially serious outcome and possibly costly recovery from accidental radioactivity put into steel. 

The heteropolyacids are very soluble in water. They can form sparingly soluble or insoluble salts with ions such as ammonium, cerium, cesium, potassium, silver, and such. The acids are often soluble in organic solvents, such as alcohols, ketones, carboxylic acids, and carboxylic esters. Long-chain tetraalkylammonium salts can also be soluble in organic solvents. In a sense, heteropolyacids are soluble versions of insoluble metal oxide catalysts. They can be used as catalysts both in solution and as solids. A catalyst that is soluble in water would be a solid if used alone or in a hydrocarbon medium. They can also be placed on insoluble supports. In the insoluble forms at least, they offer the advantages of easy separation and recovery for reuse. 

Cesium Ali et al. 1985 Study of 25 depressed individuals decreased levels of cesium that increased during recovery compared with control subjects. 

Catalytic synthesis of l-ethyl>6-fluoro-l,4-dihydro-4-oxo-7-(l-piperazinyl)-quinoline-3-carboxylic acid ethyl ester (Norfloxacin ethyl ester) (15a). To a dry 15 mL recovery flask equipped with a reflux condenser was added 13 (150 mg, 0.5 mmole), (R)-binap (10 mg, 0.017 mmole), cesium carbonate (360 mg, 0.950 mmole), piperazine (215 mg, 2.5 mmole), Pd2(dba)3 (10 mg, 0.010 mmole), and 1.5 mL of DMF. The reaction vessel was purged with nitrogen and heated to reflux. After three hours, the reaction mixture was cooled to room temperature, and the solvent was removed under reduced pressure. The residue was purified by thin-layer chromatography on a 500 micron silica gel preparative plate with an elution mixture of chloroform methanol water ammonia (80 20 2 0.2) to give 101 mg of 15a as an off-white solid in 58% yield and, separately, 29 mg of 17 as a light brown solid in 22% yield. Using this procedure, the yield of 15a... 

Recovery and Purification of Cesium-137 from Purex Waste Using Synthetic Zeolites... 

The recovery and purification of cesium-137 from Purex acid waste using a synthetic zeolite has been studied. Zeolite capacity and selectivity for cesium were determined. Stability of the synthetic zeolite to high radiation fields and chemical attack was adequately demonstrated. Kilocurie quantities of cesium-137 of 98+% chemical purity were prepared using zeolite ion exchange. 

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