Cements in Radioactive Waste Disposal: Some Mineralogical Considerations

C. E. McCulloch, M. J. Angus, R. W. Crawford, A. A. Rahman and F. P. Glasser
Department of Chemistry, University of Aberdeen, Meston Walk, Old Aberdeen AB9 2UE, Scotland

Abstract: Cementitious matrices are being assessed for immobilization of radioactive wastes. This paper discusses some mineralogical aspects of cement chemistry and the uses of siliceous minerals as selective sorbants to enhance immobilization potential.

Studies of sorption and leaching of caesium from pulverized fuel ash (PFA), blast furnace slag, tobermorite, xonotlite, and clinoptilolite are reported. The role of incorporation of these additives in cement and the effect on the nature of the composite matrix on caesium behaviour has been investigated. Specific mechanisms of the interaction of additives with highly alkaline cement environment are described. While slags, PFA, and clinoptilolite undergo reaction at different rates, tobermorite and xonotlite appear to be stable in cement.

Keywords: radioactive waste • cement • caesium • ash • slag • tobermorite • xonotlite • clinoptilolite

Mineralogical Magazine; April 1985 v. 49; no. 351; p. 211-221; DOI: 10.1180/minmag.1985.049.351.08
© 1985, The Mineralogical Society
Mineralogical Society (www.minersoc.org)