Method for confining a substance by vitrification

一种玻璃化、化学物质的技术，应用在化学仪器和方法、固体废物的清除、运输和包装等方向，能够解决并入程度限制等问题，达到良好安全水平、低可接近性的效果

Active Publication Date: 2008-07-09
COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore the degree of incorporation is limited

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0107] Embodiment 1: the production of glass frit

[0108] The frits tested had the following chemical composition, expressed in mass %: SiO 2 : 53.5%+B 2 o 3 : 16.5%+Fe 2 o 3 : 9.1%+Na 2 O: 6.4%+Al 2 o 3 : 3.9%+CaO: 4.8%+Li 2 O: 2.3%+ZnO: 2.9%+ZrO 2 : 0.6%.

[0109] This is a conventional borosilicate frit, hereinafter referred to as "type R7 / T7", which is used in La Hague (France) as a vitrification aid for the present vitrification of fission product solutions, with the addition of iron according to the invention , in order to obtain a glass frit with "redox power". In this example, it is a glass frit with the desired reducing power.

[0110] The redox state of the frit is determined by endowing a given Fe II / Fe III ratio is fixed. Choose Fe II / Fe III The ratio so is 9 / 1. This ratio is obtained with the help of graphite used as a reducing agent for iron. Therefore, the amount of graphite to be added depends inter alia on the redox state desired to be imp...

Embodiment 2

[0114] Example 2: Containment of waste

[0115] The use of the reducing glass frit obtained according to Example 1 was tested for various applications suitable for ultimately having a reduced glass.

[0116] The first application concerns the solubilization of cerium, which is often present in the solution to be vitrified and is the main reagent that mimics plutonium in an inert manner.

[0117] The inventors of the present invention noticed that at Ce +III state of cerium than in the Ce +IV The cerium state is more soluble. They observed that in order to be able to incorporate more cerium-rich waste, it is proposed to make reducing glasses.

[0118] The reducing frit of Example 1 is therefore denser than that with CeO 2 Form (i.e. Ce +IV state) of cerium was mixed: without adding additives or other materials, 100 g of cerium with different cerium content (relative to CeO 2 A mixture of 0.4% to 10.5% by mass) was heated to 1200° C. in a muffle furnace under air.

[0119...

Embodiment 3

[0122] Example 3: Reduction of Foaming

[0123] Another application of the "redox-capable" glass frit according to the invention was tested in order to prevent possible blistering phenomena during the vitrification process. These phenomena are due to a sharp increase in temperature, which causes the reduction of certain elements; the oxygen lost during this reduction then leaves in the form of bubbles and forms foam on the surface of the glass.

[0124] The reducing glass frit of Example 1 makes it possible to preventively reduce the polyvalent species responsible for foam formation. As a result, the oxygen pressure in the glass cell is too low for the reduction reaction and the departure of oxygen in the form of bubbles to occur due to the increase in temperature.

[0125] Experiments confirming this conclusion were carried out on approximately 500 g of molten glass simulated by mixing 388 g of the same reducing frit as provided above and 130 g of calcined glass at 1200° C. ...

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Abstract

The present invention relates to a process for the manufacture of a glass frit for the containment by vitrification of a material comprising at least one oxidizable or reducible chemical species, and also to a process for the containment of said material by vitrification. The process for the manufacture of the glass frit comprises a step of incorporating into a raw glass frit at least one redox couple, the nature and the amount of which make it possible to maintain said at least one chemical species in its oxidized or reduced state. The containment process comprises mixing and hot melting the resulting glass frit and the material to be contained. The present invention makes it possible to optimize the containment of pollutants such as radionucleides, metals and metalloids. The material may be nuclear waste or a material derived from the incineration of household refuse.

Description

technical field [0001] The present invention relates to a method of containing (encapsulation or containment) a substance (substance) by vitrification. [0002] The substances targeted are mainly inorganic waste or waste in solution. The present invention may, for example, contain nuclear waste in a glass matrix. [0003] The present invention can also encompass any industrial waste including inorganic matter, especially polluting metals and / or polluting metal ions. Mention may be made, for example, of nuclear waste, solid residues from the incineration of domestic waste, especially residues consisting of boiler bottom ash, “fly” ash, filter cakes from neutralization and disposal of incineration fumes. [0004] The present invention provides an improvement over prior art methods for containing waste by vitrification. Background technique [0005] In the cumbersome example of containment by vitrification of nuclear waste or household waste incineration residues, the glasse...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C03C1/00G21F9/30C03C3/093B09B3/00
CPCC03C3/093C03C14/004C03C2214/14G21F9/305C03C8/06C03C3/095B09B3/29C03C1/00G21F9/30B09B3/00
Inventor 奥利维耶·皮内蒂埃里·布利斯索恩阿涅丝·格朗让索菲·舒勒
Owner COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
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