METHOD FOR IMMOBILIZING ASH RESIDUE OF RADIOACTIVE AND TOXIC WASTE COMBUSTION PROCESS Russian patent published in 1999 - IPC

FIELD: recovery of mixed wastes. SUBSTANCE: ferric oxide powder of FeO:Fe₂O₃:Fe₃O₄ composition with proportion of ingredients being (25-40) : (40-10) : (35-50) mass percent is mixed up with ash residue of radioactive and toxic wastes and 50% solution of orthophosphate acid with mass proportion of ΣFe_xO_y : wastes = 1 : (2.2-2.5) and solid : liquid = 1 : (1.2-1.4). After stirring paste is introduced in molds for hardening. Hard material obtained in the process is water-proof chemically hardening ferric phosphate cement which reliably immobilizes radioactive and toxic wastes. EFFECT: improved reliability of immobilizing radioactive and toxic wastes. 3 cl, 4 tbl, 2 ex