SOLIDIFYING PROCESS FOR NUCLEAR AND OTHER RADIOACTIVE WASTES Russian patent published in 2002 - IPC

FIELD: handling nuclear and other radioactive wastes. SUBSTANCE: porous vitroceramic blocks used for solidifying liquid radioactive wastes are made of hollow vitroceramic microspheres extracted from volatile ash formed in coal combustion. Block is shaped as sponge and is distinguished by high open porosity, homogeneous porous structure, size of open interglobular pores ranging between 20 and 100 mcm, thermal stability , and high resistance to most acids. In addition inner surface of block is covered with metal oxide. Solidifying process takes place in porous ceramic blocks due to absorption of solutions within block, evaporation of water at low temperatures, static heating in usual furnace, repeated saturation with solution to attain desired filling, binding of radionuclides by means of large-surface resistant oxides introduced in block interior, complete disintegration of salts directly within porous space of block, reliable immobilization of radionuclides and other radioactive wastes inside block by calcination of saturated vitroceramic matrix, block treatment at high temperatures and high pressures, and block encapsulation in glass or ceramic shell. EFFECT: enhanced stability of solidified form and effectiveness of liquid waste treatment. 26 cl, 1 dwg, 9 tbl