Minerals as the Matrix Material for Immobilization
of Radionuclides

A. R. Kotelnikov

Institute of Experimental Mineralogy, Russian Academy of Sciences, Chernogolovka, Moscow oblast, 142432 Russia

Received December 5, 1996

Abstract—Solid solutions of rock-forming and accessory minerals are suggested for fixing radioactive waste,
based on the concept of managing hazardous industrial waste and the principle of phase and chemical confor-
mity in the system radionuclide form–host rock, which are accepted in engineering geochemistry. The rates of
leaching the chemical elements from natural minerals (feldspars, feldspathoids, and apatite) are experimentally
obtained, and these minerals are shown to be promising matrices for the immobilization of radionuclides. A
method is proposed to synthesize the forms for immobilizing strontium and cesium. This method is based on
sorption of these elements by zeolites and t he consequent conversion of Sr- and Cs-containing zeolites into
stable matrix materials—solid solutions of feldspars and feldspathoids. Data are given on the rates of Sr and Cs
leaching from synthetic aluminosilicates, and it is proved that these materials are compatible with Synroc-C in
the rates of leaching elements.