Other

Catherine J Simmons

Pedro B Macedo

Joseph H Simmons

Nicholas Lagakos

Danh C Tran

Robert K Mohr

Herbert G Sutter

Theodore Aaron Litovitz

A liquid containing radioactive ions is purified (decontaminated) by contacting the same with an inorganic ion exchange composition having ion exchange sites which can be occupied by the radioactive ions from the liquid. The ion exchange composition is a mixture of an ion exchange medium and an additive which is relatively inert to the ion exchange process and which is a sintering aid for the ion exchange medium designed to lower the sintering temperature of the ion exchange composition. The ion exchange composition may be disposed within a suitable container (e.g., cannister), e.g., made of 304L stainless steel or Inconel 601 and the ion exchange process may be carried out in such container. Alternatively, the ion exchange medium can be employed without being previously admixed with the additive. The additive, if desired, can be admixed at a later stage with the contaminated medium. Thereafter, the mixture may be sintered and disposed of in any desirable manner as by underground burial of the spent mixture within the container. Also, the container may be placed within a suitably designed furnace for carrying out the ion exchange process, sintering of the ion exchange composition and its safe disposal. Methods are also described for making a homogeneous mixture of the ion exchange medium and the additive which, for example, have a certain defined density and particle size relationship.

Purification of contaminated liquid

This invention relates to the immobilization of toxic, e.g., radioactive materials, internally in a silicate glass or silica gel matrix for extremely long periods of time. Toxic materials, such as radioactive wastes containing radioactive anions, and in some cases cations, which may be in the form of liquids, or solids dissolved or dispersed in liquids or gases, are internally incorporated into a glass matrix, having hydrous organofunctionalsiloxy groups, e.g., hydrous aminoalkylsiloxy or carboxyorganosiloxy, bonded to silicon atoms of said glass and/or hydrous polyvalent metals bonded to silicon atoms of said glass through divalent oxygen linkages or otherwise immobilized therein, by a process which involves the ion exchange of said toxic, radioactive anions with hydroxyl groups attached to said organofunctionalsiloxy groups or with hydroxyl groups attached to the hydrous polyvalent metal. Thereafter, the resulting glass now characterized by a distribution of internally bonded or immobilized, toxic, radioactive anions can be packaged in suitable containers, and disposed of as by burial, and/or they can be sintered to collapse the pores thereof to disposal or for producing useful radiation sources. The porous glass or a porous silica gel having said silicon-bonded organofunctionalsiloxy groups and/or said hydrous polyvalent metal oxy groups, the pores of said glass or silica gel remaining open and uncollapsed, can be used advantageously as a backfill for an underground radioactive waste burial site and as overpack in the waste disposal container. Also included is a novel method for bonding the polyvalent metal to the porous silica glass or gel by substituting the protons of the silicon-bonded hydroxyl groups thereof with an alkali metal or ammonium cation followed by displacement of said cation with the non-radioactive polyvalent metal cation.

Fixation by anion exchange of toxic materials in a glass matrix

This invention relates to the immobilization of toxic materials, e.g., radioactive materials, in glass for extremely long periods of time. Toxic materials, such as radioactive wastes, which may be in the form of liquids, or solids dissolved or dispersed in liquids or gases, are deposited in a glass container which is heated to evaporate off non-radioactive volatile materials, if present; to decompose salts, such as nitrates, if any, and to drive off volatile non-radioactive decomposition products, and then to collapse the walls of said container on said radwaste and seal the container and immobilize the contained radwaste, and then burying the resulting product underground or at sea. In another embodiment, the glass container also contains glass particles, e.g., spheres or granules, on which the radwaste solids are deposited. In other embodiments, the glass container can be made of porous glass or non-porous glass, and/or the contained glass particles can be made of porous or non-porous glass or mixtures of porous or non-porous glass, and/or the glass container can be open at one end and closed at the other or open at both ends, and/or the glass container can be closed at one end with a porous or non-porous closure and open at the other end or closed at the other end with a porous closure. When a porous glass container and/or porous glass particles are used, the radwaste deposits within the pores of the glass which are closed during the subsequent heating step after non-radioactive volatiles have been driven off and prior to sealing the container. There results a substantially impervious glass article in which the radwaste is entrapped and which is highly resistant to leaching action. The products resulting from the use of porous glass, as the container, contents, or both, can be used as sources of radioactivity for a variety of applications in medicine, sterilization, food preservation and any other application where radiation can be beneficially employed.

Immobilization of radwastes in glass containers and products formed

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.

Fixation by ion exchange of toxic materials in a glass matrix

This invention relates to the immobilization of toxic, e.g., radioactive materials, internally in a silicate glass or silica gel matrix for extremely long periods of time. Toxic materials, such as radioactive wastes containing radioactive anions, and in some cases cations, which may be in the form of liquids, or solids dissolved or dispersed in liquids or gases, are internally incorporated into a glass matrix, having hydrous organofunctionalsiloxy groups, e.g., hydrous aminoalkylsiloxy or carboxyorganosiloxy, bonded to silicon atoms of said glass and/or hydrous polyvalent metals bonded to silicon atoms of said glass through divalent oxygen linkages or otherwise immobilized therein, by a process which involves the ion exchange of said toxic, radioactive anions with hydroxyl groups attached to said organofunctionalsiloxy groups or with hydroxyl groups attached to the hydrous polyvalent metal. Thereafter, the resulting glass now characterized by a distribution of internally bonded or immobilized, toxic, radioactive anions can be packaged in suitable containers, and disposed of as by burial, and/or they can be sintered to collapse the pores thereof prior to disposal or for producing useful radiation sources. The porous glass or a porous silica gel having said silicon-bonded organofunctionalsiloxy groups and/or said hydrous polyvalent metal oxy groups, the pores of said glass or silica gel remaining open and uncollapsed, can be used advantageously as a backfill for an underground radioactive waste burial site and as overpack in the waste disposal container. Also included is a novel method for bonding the polyvalent metal to the porous silica glass or gel by substituting the protons of the silicon-bonded hydroxyl groups thereof with an alkali metal or ammonium cation followed by displacement of said cation with the non-radioactive polyvalent metal cation.

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Bethesda, MD, United States of America

Catherine J Simmons