The hydrothermal leaching behaviour and properties of sodium-calcium aluminophosphosilicate glasses.


Glasses based on a mixture of the minerals tourmaline, bentonite, and apatite (calcium phosphate) have been prepared. These glasses can be tailored to produce leach solutions that will readily precipitate apatites and clay minerals or zeolites. The leaching properties of a glass containing Cs, Sr, and U have been studied in the presence of a geochemical buffer of apatite and bentonite. The leaching of Sr and Cs is significantly retarded in the buffer. A nuclear waste form of glass of the composition 20CaO-6P sup 2 O sup 5 -8B sup 2 O sup 3 -10Na sup 2 O-34SiO sup 2 -15Al sup 2 O sup 3 -3Fe sup 2 O sup 3 -10CuO with a melting temperature of about 1000 deg C is proposed. Melling,-P.J.; Karkhanis,-S.N.; Fyfe,-W.S.; Bancroft,-G.M. (University of Western Ontario, London (Canada). Dept. of Chemistry; University-of-Western-Ontario,-London (Canada). Dept. of Geology; University-of-Western-Ontario,-London (Canada). Centre for Chemical Physics)