PROCESS FOR WASTE CONFINEMENT BY VITRIFICATION IN METAL CANS

• US 20110144408A1
• Filed: 07/28/2009
• Published: 06/16/2011
• Est. Priority Date: 07/28/2008
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat A L'Energie Atomique et AUX Energies Alternatives
• Inventors: Bousquet, Nicolas, Rabiller, Helene, Pinet, Oliver, Boen, Roger, Dussossdy, Jean-Luc, Gruber, Philippe, Lacombe, Jacques
• Granted Patent: US 10,538,448 B2
• Time in Patent Office: Days
• US Class Current: 588/15
• CPC Class Codes: B09B 3/29 involving a melting or softening step
• CPC Class Codes: C03B 5/005 of glass-forming waste materials disposal or transformation of solid waste in general B09B; treatment of radioactive waste G21F9/00
• CPC Class Codes: C03B 5/06 in pot furnaces C03B5/02 takes precedence
• CPC Class Codes: Y02P 40/50 Glass production, e.g. reusing waste heat during processing or shaping

Abstract

Process for confinement of waste containing at least one chemical species to be confined, by in-can vitrification in a hot metal can into which waste and a vitrification additive are added, the waste and the vitrification additive are melted to obtain a glass melt which is then cooled, characterised in that at least one oxidising agent is also added into the metal can and in that the concentration of oxidising agent(s) expressed as oxide(s) in the glass melt is between 0.1 and 20% by mass, preferably 4 and 20% by mass, even more preferably 5 and 15% by mass, and even more preferably 10 and 13% by mass of the glass melt mass.

Claims

1. Process for confining a waste containing at least one chemical species to be confined, by vitrification in a heated metal can, wherein the waste and a vitrification additive are fed into the metal can, the waste and the vitrification additive are melted to obtain a glass melt, and the glass melt is cooled, characterized in that at least one oxidizing agent is further fed into the metal can and wherein the concentration of oxidizing agent(s) expressed as oxide(s) in the glass melt ranges from 0.1 to 20% by mass of the mass of the glass melt.

2. Process according to claim 1, wherein the oxidizing agent(s) is (are) chosen from among multivalent oxidizing agents.

3. Process according to claim 2, wherein the oxidizing agent(s) is (are) chosen from among multivalent oxidizing species of iron, chromium, vanadium, antimony, titanium, arsenic, cerium, manganese, chromium, ruthenium, and mixtures thereof.

4. Process according to claim 3, wherein the oxidizing agent(s) is (are) chosen from among Fe³⁺, Ce⁴⁺, Mn⁴⁺, Sb⁵⁺, As⁵⁺, V⁵⁺, Ru⁴⁺, and mixtures thereof.

5. Process according to claim 2, wherein the oxidizing agent(s) is (are) in the form of one or more oxides, or precursors of oxides.

6. Process according to claim 5, wherein the oxidizing agent is an agent that has a limiting effect on the corrosion of the metal can.

7. Process according to claim 3, wherein the concentration of the oxidizing agent, for an oxidizing agent used alone, is in a range of from 0.1% to 1% by mass when the oxidizing species is chromium (Cr³⁺), expressed as Cr₂O₃;

from 1 to 15% by mass when the oxidizing agent is vanadium (V⁵⁺), expressed as V₂O₅;

from 0.5 to 7 or 8% by mass when the oxidizing agent is antimony (Sb⁵⁺), expressed as Sb₂O₅;

from 1 to 15% by mass when the oxidizing agent is titanium (Ti⁴⁺), expressed as TiO₂;

from 0.5 to 7 or 8% by mass when the oxidizing agent is arsenic (As⁵⁺), expressed as As₂O₅;

from 0.5 to 10% by mass when the oxidizing agent is cerium (Ce⁴⁺), expressed as CeO₂;

from 0.1 to 2% by mass when the oxidizing agent is manganese (Mn⁴⁺), expressed as MnO₂; and

from 1 to 20% by mass when the oxidizing agent is iron (Fe³⁺), expressed as Fe₂O₃.

8. Process according to claim 1, wherein the oxidizing agent is added in the form of a powder composed preferably of a mixture of oxide powders.

9. Process according to claim 1, wherein the oxidizing agent is added in the form of a glass.

10. Process according to claim 1, wherein the oxidizing agent is mixed with the waste before the waste is fed into the metal can.

11. Process according to claim 1, wherein the oxidizing agent is mixed with the vitrification additive before the vitrification additive is fed into the metal can.

12. Process according to claim 1, wherein the oxidizing agent is fed directly into the metal can, separately from the waste and the vitrification additive.

13. Process according to claim 1, wherein the oxidizing agent is fed into the metal can continuously.

14. Process according to claim 1, wherein the oxidizing agent is fed into the metal can discontinuously.

15. Process according to claim 1, wherein the metal can is made from an iron-based alloy or a nickel-based alloy.

16. Process according to claim 1, wherein the vitrification additive is either in the form of a mixture of oxide powders or a glass.

17. Process according to claim 1, wherein the vitrification additive includes oxides chosen from among SiO₂ (silica), B₂O₃ (boric oxide), Al₂O₃ (alumina), Na₂O (sodium oxide), Fe₂O₃, CaO, Li₂O, ZnO, ZrO₂, etc.

18. Process according to claim 1, wherein the vitrification additive is a borosilicate glass or a silicate glass.

19. Process according to claim 1, wherein the chemical element to be confined is selected from the group of the following chemical elements:

Al, As, B, Ba, Ca, Ce, Cd, Cr, Cs, F, Fe, Gd, Hg, Li, Mg, Mn, Mo, Na, Ni, Nd, P, Pb, S, Sb, Tc, Ti, V, Zn, Zr, actinides such as Pu, platinoids, or their isotopes, particularly their radioactive isotopes, and mixtures thereof.

20. Process according to claim 1, wherein the waste is a nuclear waste in solid or liquid form.

21. Process according to claim 20, wherein the nuclear waste is a radioactive liquid effluent such as a radioactive solution.

22. Process according to claim 20, wherein the nuclear waste is a cullet of a radioactive liquid effluent, particularly a medium activity effluent.

23. Process according to claim 1, wherein the waste is a waste derived from the incineration of radioactive waste or household waste.

24. Process according to claim 1, further comprising the step of pouring the glass melt into a container and cooling said container.

25. Process according to claim 1, wherein the glass melt is cooled in the metal can in which it was prepared.

26. Process according to claim 1, wherein the concentration of oxidizing agent in the glass melt ranges from 0.4 to 20% by mass.

27. Process according to claim 1, wherein the concentration of oxidizing agent in the glass melt ranges from 0.5 to 15% by mass.

28. Process according to claim 1, wherein the concentration of oxidizing agent in the glass melt ranges from 10 to 13% by mass.

29. Process according to claim 7, wherein when the oxidizing agent is iron, the concentration is in a range from 0.1 to 15% by mass.

30. Process according to claim 7, wherein when the oxidizing agent is iron, the concentration is in a range from 0.3 to 13% by mass.

31. Process according to claim 7, wherein when the oxidizing agent is iron, the concentration is in a range from 0.5 to 13% by mass.

33. Process according to claim 7, wherein when the oxidizing agent is iron, the concentration is in a range from 12 to 13% by mass.

34. Process according to claim 7, wherein when the oxidizing agent is iron, the concentration is in a range from 12 to 6% by mass.

35. Process according to claim 9, wherein the oxidizing agent is selected from the group consisting of a glass frit, glass beads or glass pieces.

36. Process according to claim 16, wherein when the oxide powder is a glass, it is selected from the group consisting of a glass frit, glass beads or glass pieces.