WASTE DISPOSAL METHOD

Abstract

The invention relates to a method for the disposal of a composite material, in particular a composite material contaminated, for example, by radioactivity and containing fluorine impurities. The inventive method for the disposal of a component containing a composite material with a composite matrix and a technical fiber, is characterized in that the component is chemically gasified, wherein the composite material is technically completely decomposed into its basic components, wherein in a first step the composite matrix is dissolved and in a subsequent step the remaining starting materials and intermediate products are thermally decomposed and reacted with added process gases, wherein at least in the subsequent step a reactive gas is supplied and the subsequent step is conducted endothermically.

Claims

1. Method of disposing of a component containing a composite material, the composite material comprising a composite matrix and an engineered fiber, wherein the component is chemically gasified, the composite material being completely broken down technically into its basic constituents, the composite matrix being dissolved in a first step and, in a subsequent step, the remaining starting materials and intermediate products being broken down thermally and reacted with added process gases, a reactive gas being supplied at least in the subsequent step and the subsequent step being conducted endothermically.

2. Method according to claim 1, wherein the technical fiber is a carbon fiber and the reactive gas contains oxygen.

3. Method according to claim 2, wherein the oxygen supplied amounts to a maximum of 8% of the reaction atmosphere.

4. Method according to claim 1, wherein the technical fiber is a glass fiber and the reactive gas contains fluorine.

5. Method according to claim 1, wherein the first step comprises hydropyrolysis.

6. Method according to claim 5, wherein gaseous hydrogen halides are present as a result from hydropyrolysis, which are subsequently isolated.

7. Method according to claim 6, wherein the gaseous hydrogen halides are isolated by neutralization in an alkaline washing solution.

8. Method according to claim 1, wherein the subsequent step is carried out at a temperature of more than 800° C., preferably at more than 1,200° C., particularly preferably at more than 1,350° C.

9. Method according to claim 1, wherein the subsequent step is carried out at a temperature of at most 1,600° C., preferably at most 1,500° C.

10. Method according to claim 1, wherein the process is started with a maximum energy input corresponding to the composite material to be processed, so that all the constituents of the composite material are chemically gasified substantially simultaneously.

11. Method according to claim 1, wherein the chemical gasification is carried out under the action of mechanical energy.

12. Method according to claim 11, wherein the mechanical energy is introduced via a rotary motion.

13. Method according to claim 11, wherein the mechanical energy is introduced via a swirling of the component and/or parts of the component.

14. Method according to claim 1, wherein a moderator is supplied to the process for energy regulation.

15. Method according to claim 14, wherein the moderator contains water, the water being introduced into the process via a residual moisture content of the material of the component.

16. Method according to claim 14, wherein the moderator is fed to the process in gaseous form, the moderator containing water vapor, ammonia and/or carbon dioxide.

17. Method according to claim 1, wherein metal compounds and/or semi-metal compounds, in particular uranium compounds, remain as solids in the slag.

18. Method according to claim 1, wherein any condensable substances of the component which may be present and have been at most partially converted are post-combusted.

Description

[0039] In the Figures:

[0040] FIG. 1 shows an example of embodiment of a process flow for the disposal of a component made of a composite material.

[0041] FIG. 1 shows an example of embodiment of a process flow for the disposal of a component made of a composite material. First, with reference numeral 1, the component made of a composite material is fed to the process. The component may be, for example, a centrifuge body of a uranium enrichment plant. The component may comprise a composite material, in particular a fiber composite with a fiber embedded in a matrix material. For example, the composite material may be a carbon fiber reinforced plastic, also called CFRP, or a composite material comprising aramid fiber. Energy is supplied to the process with reference number 2, a moderator is supplied with reference number 3, and an oxidizing agent is supplied with reference number 4. The component can be fed into a furnace, for example a rotary kiln or paddle kiln or a fluidized bed reactor. On the one hand, energy is supplied in the form of thermal energy by heating the furnace to at least 800° C. On the other hand, energy is supplied to the process in the form of mechanical energy. In this context, the supply of mechanical energy primarily serves to create new surfaces and/or to achieve a stoking effect and thus to create better attacking possibilities for an oxidizing agent. The supply of the mechanical energy can occur, for example, via a rotary motion, for example by stirring, and/or via a swirling of the component and/or parts of the component. The moderator is supplied for energetic process regulation. The moderator can be introduced into the process in the form of water as residual moisture of the material of the component. However, the moderator can also be supplied to the process alternatively or additionally in gaseous form, and in particular can also be metered in in a regulated or controlled manner, where the moderator can contain water vapor, ammonia and/or carbon dioxide. Endothermic process control can be enforced by the defined supply of the moderator as a function of the composite material to be gasified and/or the process temperature and/or the process speed. Due to the endothermic process control, the process can be controlled at any time. Further, at reference number 4, an oxidant is added to the process. The oxidant may comprise oxygen. For example, the oxidant may be a compound that readily releases oxygen, such as hydrogen peroxide, permanganate or dichromate, or may be pure oxygen. The supply of the oxidant may be controlled or regulated. As a controlled variable, the process temperature, for example, can be used. But also the volume flow rate can be used to control or regulate the feed flow of the oxidant. Both variables can be easily measured and can be easily influenced by varying the amount of oxidant fed per unit time. Process speed and material throughput are controlled or regulated in such a way that complete conversion of all gasifiable materials of the component takes place. The degree of conversion can be influenced within wide limits by the process variables energy input and mass throughput of oxidant and material to be converted.

[0042] The basic constituents of the composite material, indicated by reference number 5, are the disposal product. Reference number 6 indicates any condensable substances of the component that have been at most partially reacted. These can be post-combusted at reference number 7. Reference numeral 8 indicates possible non-gasifiable substances of the component, as well as in particular the non-gasifiable impurities such as, for example, uranium compounds.

[0043] The FIGURE is not to be understood as meaning that the process steps must be carried out in a specific sequence. Rather, it is also possible, for example, that energy is supplied again after step 4, i.e. after the supply of an oxidizing agent. Energy in the form of thermal and/or mechanical energy can also be supplied throughout the entire process. Similarly, in batch operation, condensable substances (step 6) can also be formed even before the oxidant is added in step 4.

[0044] The embodiments shown herein represents only one example of the present invention and therefore should not be construed as limiting. Alternative embodiments contemplated by the person skilled in the art are equally encompassed by the scope of protection of the present invention.

LIST OF REFERENCE NUMBERS

[0045] 1 Feeding a component made of a composite material [0046] 2 Energy supply [0047] 3 Moderator supply [0048] 4 Oxidizing agent supply [0049] 5 Basic components of the composite material [0050] 6 Partially converted condensable substances [0051] 7 Post-combustion [0052] 8 Non-gasifiable substances