초록 ▼

This invention relates to the immobilization of toxic, e.g., radioactive, materials in a silicate glass or silica gel matrix for extremely long periods of time. Toxic materials, such as radioactive wastes containing radioactive cations, which may be in the form of liquids, or solids dissolved or dis

This invention relates to the immobilization of toxic, e.g., radioactive, materials in a silicate glass or silica gel matrix for extremely long periods of time. Toxic materials, such as radioactive wastes containing radioactive cations, which may be in the form of liquids, or solids dissolved or dispersed in liquids or gases, are incorporated into a glass or silica gel matrix, having alkali metal, Group Ib metal and/or ammonium cations bonded to silicon atoms of said glass or silica gel through divalent oxygen linkages, by a process which involves the ion exchange of said toxic or radioactive cations with said alkali metal, Group Ib metal and/or ammonium cations to bind said toxic or radioactive cations to silicon atoms of said glass or silica gel through said silicon-bonded divalent oxygen linkages. Thereafter, the resulting glass or silica gel now characterized by toxic or radioactive cations bonded to silicon atoms through divalent oxygen linkages can be stored, or packaged in suitable containers, or disposed of as by burial, and/or sintered to collapse the pores thereof.

대표청구항 ▼

Process which causes the proton (H+) of silicon-bonded hydroxyl groups on the internal surfaces of porous silicate glass to undergo ion-exchange reaction without occurrence of substantial dissolution of the glass during the reaction which comprises: (a) impregnating a porous silicate glass character

Process which causes the proton (H+) of silicon-bonded hydroxyl groups on the internal surfaces of porous silicate glass to undergo ion-exchange reaction without occurrence of substantial dissolution of the glass during the reaction which comprises: (a) impregnating a porous silicate glass characterized by at least 75 mol percent SiO2, an interconnecting pore structure, and silicon-bonded hydroxyl groups on its surfaces, (b) with a liquid containing non-radioactive alkali metal cations, non-radioactive Group I(b) metal cations, ammonium cations, or mixtures thereof, (c) said liquid buffered with non-radioactive ammonium cations to maintain a pH in the range of about 11 to about 13, (d) for a period of time to provide a distribution of said non-radioactive cations within the interconnected pores of said glass, said cations being bonded to silicon through divalent oxy groups. Porous silicate glass prepared as defined in claim 1 and containing at least one part per billion by weight of radioactive cation of the group consisting of radioactive cations of rubidium, strontium, the lanthanides, cobalt, cadmium, zirconium, molybdenum, technetium, niobium, ruthenium, palladium, tellurium, cesium, barium, francium, yttrium, radium, the actinides, and mixtures thereof; said radioactive cation bonded to surface silicon through divalent oxygen linkages.