Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-15T15:19:34.571Z Has data issue: false hasContentIssue false
  • English
  • Français

Phillipsite in Cs Decontamination and Immobilization

Published online by Cambridge University Press:  02 April 2024

Sridhar Komarneni
Sridhar Komarneni*
Affiliation:
Materials Research Laboratory and Department of Agronomy, The Pennsylvania State University, University Park, Pennsylvania 16802
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The Cs selectivity of several natural zeolitic tuffs and synthetic zeolites was measured. Phillipsite-rich tuffs from California and Nevada exchanged 13.5 and 23.7%, respectively, of the Cs present in simulated alkaline defense waste containing 0.00025 M CsCl in 5.5 M NaCl-NaOH solution from the Savannah River Plant, Aiken, South Carolina; whereas mordenite-rich tuffs from Arizona and Nevada exchanged less than 12.7%. The immobilization or fixation of Cs in phillipsite unlike other zeolites can be achieved by heating the zeolite at 600°C for 4 hr in air and collapsing the silicate (aluminate) tetrahedral rings around the Cs ions to produce a Cs-feldspar-type phase. Treatment of the Cs-exchanged phillipsite-rich tuff at 800° to 1000°C resulted in pollucite, CsAlSi2O6, which also “locks in” the Cs ions in its structure. The fixation of Cs exchanged in phillipsite can also be achieved by the formation of pollucite upon hydrothermal treatment at 300°C and 30 MPa pressure within 12 hr. These results suggest that phillipsite-rich tuffs are good candidates for Cs immobilization by heat treatment at low temperatures after they have been used as sorbents in waste decontamination.

Резюме

Резюме

Измерялась Сѕ селективность нескольких природных цеолитовых туфов и синтетических туфов. Обогащенные филлипситом туфы из Калифорнии и Невады обменивали соответственно 13,5 и 23,7% Се, присутствующега в 5,5 М №С1-МаОН растворе, содержащем количество 0,00025 М СвС1, имитирующем щелочные отходы фабрики Савана Ривер в Аикен, Южная Каролина. В то же самое время обогащенные морденитом туфы из Аризоны и Невады обменивали менее 12.7%. Неподвижность или фиксация Сз в филлипсите в противоположность к другим цеолитом достигается путем обогрева цеолита при 600°С в течение 4 часов в воздухе и разрушения силикатных (алюминатных) тетраэдрических колец вокруг ионов Сз для образования фазы типа Св-полевой шпат. Обработка С8-обменного обогащенного филлипситом туфа при температуре от 800° до 1000°С приводила к образованию поллуцита, С$А1$1206, который также “закупоривал” ионы Ск в своей структуре. Фиксация обменного Св в филлипсите могла также быть достигнута путем образования поллуцита в результате гидротермической обработки при температуре 300°С и давлении ЗОМПа в течение 12 часов. Эти результаты указывают на то, что обогащенные филлипситом туфы являются хорошим материалом для “нейтрализации” Св путем термической обработки при низких температурах после того, как они использовались в качестве сорбентов при очищении отходов. [Е.G.]

Resümee

Resümee

Es wurde die Cs-Selektivität von verschiedenen natürlichen Zeolith-Tuffen und synthetischen Zeolithen gemessen. Phillipsit-reiche Tuffe von Kalifornien und Nevada tauschten 13,5 bzw. 23,7% des in simuliertem alkalischem Abfall vorhandenen Cs aus, der 0,00025 m CsCl in einer 5,5 m NaCl-NaOH-Lösung von der Savannah River Plant, Aiken, South Carolina, enthielt. Mordenit-reiche Tuffe von Arizona und Nevada tauschen dagegen weniger als 12,7% aus. Die Immobilisierung oder Fixierung von Cs in Phillipsit kann anders als bei anderen Zeolithen dutch Erhitzen des Zeolithes auf 600°C in Luft für 4 Stunden erreicht werden, wodurch die Silikat- (Aluminat-) Tetraederringe um das Cs-Ion kollabieren und eine feldspatartige Cs-Phase entsteht. Eine Behandlung der Cs-ausgetauschten Phillipsit-reichen Tuffe bei 800°−100°C führt zur Bildung von Pollucit CsAlSi2O6, der ebenfalls die Cs-Ionen in seiner Struktur “einsperrt.” Die fixierung von durch Phillipsit ausgetauschtem Cs kann auch durch die Bildung von Pollucit aufgrund hydrothermaler Behandlung bei 300°C und 30 MPa Druck über 12 Stunden erreicht werden. Diese Ergebnisse deuten darauf hin, daß Phillipsit-reiche Tuffe gute Anwärter für die Cs-Immobilisierung dutch Behandlung bei niedrigen Temperaturen sind, nachdem sie als Sorbenten bei der Abfalldekontamination verwendet wurden. [U.W.]

Résumé

Résumé

On a mesuré la sélectivité Cs de plusieurs tufts zéolitiques naturels et de zéolites synthétiques. Des tuffs riches en phillipsite de Californie et du Nevada ont échangé 13,5 et 23,7% respectivement du Cs présent dans un déchet de dàfense alkalin simulé contenant 0,00025 M CsCl dans une solution 5,5 M NaCl-NaOH provenant du Savannah River Plant, Aiken, Caroline du Sud; tandis que des tuffs riches en mordénite d'Arizona et du Nevada ont echangé moins que 12,7%. L'immobilisation ou la fixation de Cs dans la phillipsite, dissimilairement aux autres zéolites, peuvent être atteintes par échauffement de la zéolite à 600°C pendant 4 heures à l'air et en fermant les anneaux silicates (aluminate) tetraédriques autour des ions Cs pour produire une phase du type Cs-feldspar. Le traitement du tuff riche en phillipsite échangé au Cs de 800° à 1000°C a resulté en de la pollucite, CsAlSi2O6, qui enferme aussi les ions Cs dans sa structure. La fixation de Cs échangé dans la phillipsite peut aussi être atteinte par la formation de pollucite lors du traitement hydrothermique à 300°C et 30 MPa de pression endéans 12 heures. Ces résultats suggèrent que les tuffs riches en phillipsite sont de bons candidats pour l'immobilisation de Cs par traitement à la chaleur à de basses températures après qu'ils aient été employés comme solvants dans la décontamination de déchets. [D.J.]

Keywords

Cation exchangeCesiumCs-feldsparNuclear waste disposalPhillipsitePolluciteThermal treatmentZeolite
Type
Research Article
Information
Clays and Clay Minerals , Volume 33 , Issue 2 , April 1985 , pp. 145 - 151
Copyright
Copyright © 1985, The Clay Minerals Society

References

Ames, L. L., 1960 The cation sieve properties of clinop-tilolite Amer. Mineral. 45 689–700.Google Scholar
Ames, L. L., 1961 Cation sieve properties of the open zeolites chabazite, mordenite, erionite, and clinoptilolite Amer. Mineral. 46 1120–1131.Google Scholar
Ames, L. L., 1963 Mass cation relationships of some zeolites in the region of high competing cation concentrations Amer. Mineral. 48 868–882.Google Scholar
Barrer, R. M., 1978 Zeolites andClay Minerals as Sorbents and Molecular Sieves London Academic Press.Google Scholar
Brandt, H. L., 1970 B-plant recovery of cesium from Purex supernatant United States Atomic Energy Commission, Hanford, Washington, Report .CrossRefGoogle Scholar
Breck, D. W., 1974 Zeolite Molecular Sieves: Structure, Chemistry and Use New York Wiley.Google Scholar
Buckingham, J. S., 1970 Laboratory evaluation of zeolite material for removing radioactive cesium from alkaline waste solutons United States Atomic Energy Commission, Hanford, Washington, Report .Google Scholar
Ebra, M. A., Wallace, R. M., Walker, D. D. and Wille, R. A., 1982 Tailored ion exchange resins for combined cesium and strontium removal from soluble SRP high-level waste Scienfic Basis for Nuclear Waste Management 6 633–640.Google Scholar
Forberg, S., Westermark, T., Arnek, R., Grenthe, I., Faith, L. and Anderson, S., 1980 Fixation of medium-level waste in titanates and zeolites: progress towards a system for transfer of nuclear reactor activities from spent organic to inorganic ion exchangers Scientific Basis for Nuclear Waste Management 2 867–874.CrossRefGoogle Scholar
Hofstetter, K. J. and Hitz, C. G., 1983 The use of the submerged demineralizer system at Three Mile Island Separation Sci. Tech. 18 1747–1764.CrossRefGoogle Scholar
Hoss, H. and Roy, R., 1960 Zeolite studies III: on natural phillipsite, gismondite, harmotome, chabazite, and gmelinite Beitr. Mineral. Petrog. 7 389–408.Google Scholar
IAEA, 1972 Use of local minerals in the treatment of radioactive wastes Tech. Rep. Ser. 136 61–64.Google Scholar
Kelsey, P. V. Jr., Schuman, R. P., Welch, J. M., Owen, D. E. and Flinn, J. E., 1982 Iron-enriched basalt and its application to Three-Mile Island radioactive waste disposal Scientific Basis for Nuclear Waste Management 6 533–540.Google Scholar
Knoll, K. C., 1963 The effect of heat on vaporization and elution of 85Sr and 137Cs adsorbed on zeolites United States Atomic Energy Commission, Hanford, Washington, Report .Google Scholar
Komarneni, S. and Roy, R., 1981 Zeolites for fixation of cesium and strontium from radwastes by thermal and hydrothermal treatments Nucl. Chem. Waste Management 2 259–264.CrossRefGoogle Scholar
Komarneni, S. and Roy, R., 1982 Alternative radwaste solidification route for Three Mile Island wastes J. Amer. Ceram. Soc. Communie. 65 198.Google Scholar
Komarneni, S. and Roy, R., 1983 Hydrothermal reaction and dissolution studies of CsAlSi5O12 in water and brines J. Amer. Ceram. Soc. 66 471–474.CrossRefGoogle Scholar
Komarneni, S. and White, W.B., 1981 Stability of pollucite in hydrothermal fluids Scientific Basis for Nuclear Waste Management 3 387–396.CrossRefGoogle Scholar
Medlin, J.H., Suhr, N.H. and Bodkin, J.B., 1969 Atomic absorption analysis of silicates employing LiBO2 fusion Atomic Absorption Newslett. 8 25–29.Google Scholar
Mercer, B. W., Ames, L. L., Sand, L. B. and Mumpton, F. A., 1978 Zeolite ion exchange in radioactive and municipal wastewater treatment Natural Zeolites: Occurrence, Properties, Use Elmsford, New York Pergamon Press 451–462.Google Scholar
Mimura, H. and Kanno, T., 1980 Processing of radioactive waste solution with zeolites (I) Thermal-transformations of Na, Cs and Sr forms of zeolites Sci. Rept. Res. Inst. Tohoka Univ., Series A 29 102–111.Google Scholar
Mumpton, F. A., 1960 Clinoptilolite redefined: mer Mineral 45 351–369.Google Scholar
Nelson, J. L. and Mercer, B. W., 1963 Ion exchange separation of cesium from alkaline waste supernatant solutions United States Atomic Energy Commission, Hanford, Washington, Report .CrossRefGoogle Scholar
Sheppard, R. A. and Gude, A. J. 3rd (1968) Distribution and genesis of authigenic silicate minerals in tuffs of Pleistocene Lake Tecopa, Inyo County, California: U.S. Geol. Surv. Prof. Pap. 597, 39 pp.Google Scholar
United States Nuclear Regulatory Commission (1980) Draft Programmatic environment impact statement related to decontamination and disposal of radioactive wastes resulting from March 1979 accident—Three Mile Island Nuclear Station, Unit 2: U.S. Nuclear Reg. Comm. Report NUREG-0683, Washington, D.C., 56 pp.Google Scholar