A METHOD FOR TREATING WASTE MATERIAL COMPRISING ORGANIC COMPONENTS AND LOW AND/OR INTERMEDIATE LEVEL RADIOACTIVE AGENTS AND A USE OF A MATERIAL

Abstract

The present invention relates to a method for treating waste material comprising organic components and low and/or intermediate level radioactive agents. The method comprises adding material comprising fibers and kaolin to the waste material in order to form a starting material, and gasifying the starting material at a temperature between 600 and 950° C. to form a gaseous fraction and a solid fraction comprising low and/or intermediate level radioactive agents, gasification residues of the organic components and metakaolin. The present invention also relates to a use of mate-rial comprising fibers and kaolin.

Claims

1. A method for treating waste material comprising organic components and low and/or intermediate level radioactive agents, wherein the method comprises adding material comprising fibers and kaolin to the waste material in order to form a starting material, gasifying the starting material at a temperature between 600 and 950° C. to form a gaseous fraction and a solid fraction comprising low and/or intermediate level radioactive agents, gasification residues of the organic components and metakaolin.

2. The method according to claim 1, wherein the method comprises adding metakaolin to the solid fraction.

3. The method according to claim 1, wherein the method comprises adding aqueous solution of a silicate or a mixture of silicates and a hydroxide or a mixture of hydroxides to the solid fraction.

4. The method according to claim 3, wherein the method comprises adding a sodium silicate or a potassium silicate or both.

5. The method according to claim 3, wherein the method comprises adding sodium hydroxide or potassium hydroxide or both.

6. The method according to claim 3, wherein the method comprises agitating the mixture until a homogenous paste is achieved.

7. The method according to claim 6, wherein the method comprises heating the homogenous paste in humid or autogenous conditions in order to initiate a polysialate polymerization process.

8. The method according to claim 6, wherein the method comprises settling the homogenous paste at room temperature.

9. The method according to claim 7, wherein the method comprises heating in order to remove water.

10. A use of material comprising fibers and kaolin for immobilizing low and/or intermediate level radioactive agents in the method according to claim 1.

11. The use according to claim 10, wherein the material comprising fibers and kaolin is deinking sludge.

12. The use according to claim 10, wherein the material comprising fibers and kaolin is fiber clay.

Description

DETAILED DESCRIPTION OF THE INVENTION

Example

[0030] Radioactive ion exchange resins and kaolin containing sludge are used as a starting material. The starting material is treated with a gasification technique in a temperature of 850° C. A solid fraction having a reduced volume is obtained from the method step. Kaolin has calcined into metakaolin at the same time.

[0031] Aqueous solution of sodium silicate (NaSiO, e.g. Zeopol 33, Huber Engineered Materials) and potassium hydroxide (KOH) is added to the solid fraction. The mixture is agitated until a homogenous paste is achieved. Mixing can be performed with known mixing devices usually used in connection with encapsulation processes.

[0032] After the solid blank has adequate mechanical properties, it may heated. Thus a finished product to be stored in the bed rock has been formed. The finished product has a loading factor from 75% to above 100%.

[0033] It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.