METHOD FOR IMMOBILIZING RADIOACTIVE AND TOXIC WASTES Russian patent published in 2002 - IPC

FIELD: recovery of radioactive and toxic wastes. SUBSTANCE: method includes concentration and crushing of wastes, their mixing with fluxing additives such as modifier prepared from electricity conducting magnetite mixed up with silicon dioxide in proportion of 0.67:1.5. Then mixture containing 12.5-35% of radioactive or toxic wastes out of total mass is charged into crucible transparent for electromagnetic field and subjected to induction melting and homogenization at 1250- 1600 C using direct induction heating. In the course of melting electrical resistance and temperature of melt are regulated by varying modifier fraction and magnetite-to-silicon-dioxide proportion in modifier. In the process electrical resistance of melt is measured by means of instrumentation system of electromagnetic field generator. As soon as steady state resistance of melt is attained, homogenization of the latter is determined whereupon melt is cooled down and end-product cool melt is removed. End product is monolithic homogeneous material. EFFECT: reduced time (shorter in average by three times) taken to immobilize high-melting toxic and radioactive wastes. 2 ex