Interaction of Uranyl Ions with Synthetic Zeolites of Type A and the Formation of Compreignacite-Like and Becquerelite-Like Products

G. W. Brindley and Marija Bastovanov1
Materials Research Laboratory and Department of Geosciences, The Pennsylvania State University University Park, Pennsylvania 16802
1 Present address: Faculty of Mining and Geology, University of Belgrade, 11000 Belgrade, Yugoslavia.

Abstract: Uranyl acetatye solutions, ranging in concentration from about 100 ppm to 3700 ppm, were re-acted with the Na-, K-, and Ca- forms of zeolite A. The crystalline products from the Na- and K-A zeolites resembled compreignacite (K2O·6UO3·11H2O) and from the Ca-A, becquerelite (CaO·6UO3·11H2O). With higher concentrations of uranyl acetate, only X-ray-amorphous products were obtained. The compreignacite-like products gave sharp X-ray powder diffraction patterns and were indexed with orthorhombic, quasi-hexagonal unit cells which showed a significant variation of the axial ratio b/a from values just greater than, to values just less than √3. The becquerelite-like phase was always accompanied by unreacted zeolite. Compreignacite was synthesized from uranyl acetate and KOH solutions at room temperature over a period of several days.

Key Words: Becquerelite • Compreignacite • Synthesis • Uranium • X-ray powder diffraction • Zeolite A

Clays and Clay Minerals; April 1982 v. 30; no. 2; p. 135-142; DOI: 10.1346/CCMN.1982.0300208
© 1982, The Clay Minerals Society
Clay Minerals Society (www.clays.org)