The article contains the results of studies on the fluorination of rare earth oxides with elemental fluorine, the results of studying the kinetics of the fluorination of a rare earth elements mixture under conditions excluding local overheating and external diffusion inhibition. A serial metallurgical mixture of rare earth oxides of a cerium subgroup manufactured by Sillamäe Mining and Chemical Plant was used as the object of the investigation. The composition and properties of the low-melting fluoride glass for immobilization of solid radioactive and toxic wastes are also given in the article.