Radioactive incineration ash and contaminated glass fiber filter material common glass curing method

Abstract

The invention relates to a common glass curing method for radioactive incineration ash and a contaminated glass fiber filter material, which comprises the following steps of: melting and curing a raw material containing the radioactive incineration ash and the contaminated glass fiber filter material by adopting a method I or a method II to prepare a glass cured body; according to the first method, raw materials of the filter material containing the radioactive incineration ash and the contaminated glass fiber comprise 0 wt%-30 wt% of the radioactive incineration ash and 70 wt%-100 wt% of the contaminated glass fiber filter material, and the melting temperature ranges from 1100 DEG C to 1400 DEG C; according to the second method, raw materials of the filter material containing the radioactive incineration ash and the contaminated glass fiber comprise 0 wt%-40 wt% of the radioactive incineration ash, 30 wt%-60 wt% of the contaminated glass fiber filter material and 15 wt%-50 wt% of an additive, and the melting temperature ranges from 900 DEG C to 1300 DEG C. According to the method, the glass solidified body meeting the disposal requirement can be effectively and stably obtained on the premise that the incineration ash component fluctuates greatly and the fly ash component contained in the contaminated glass fiber filter material is uncertain.

Description

Technical Field

[0001] The invention belongs to the technical field of radioactive nuclear waste treatment, and in particular relates to a method for co-vitrification of radioactive incineration ash and contaminated glass fiber filter material. Background Art

[0002] Combustible waste and high-efficiency filter elements account for a large proportion of the low- and medium-level radioactive waste generated during the operation of nuclear facilities. Based on the principle of minimizing radioactive waste, incineration of combustible waste and cleaning and release of the shell after disassembly of the filter element are ideal solutions. However, the radioactive incineration ash and contaminated glass fiber filter materials generated by these two technologies are not suitable for direct disposal as final products due to the risk of radioactive element leaching and radioactive aerosol diffusion.

[0003] At present, the treatment of radioactive incineration ash and contaminated glass fiber filter material is usually carried out separately by cement solidification or super compression, but cement solidification technology belongs to the capacity expansion treatment technology, which increases the amount of waste, and the solidified body has lower anti-leaching property than glass solidification technology, and super pressure has poor compatibility with these two wastes. There are also related technologies for glass solidification treatment of radioactive incineration ash and contaminated glass fiber filter material in China, but there is no engineering application. The problems are as follows: 1) For the glass solidification of the two solid wastes separately, a large amount of glass matrix composition needs to be added, which increases the cost of glass solidification and increases the weight of the solidified body under the condition of the same solid waste; 2) In the existing technology, most of the research on the glass solidification technology of radioactive incineration ash is based on the analysis of a certain type of waste, and the waste is simulated by using reagents with the same main components for experiments. In the actual engineering treatment of waste, due to the variety of radioactive combustible wastes, and the fact that the types are not selected and proportioned during incineration, but are random, the composition and proportion of radioactive incineration ash in different batches fluctuate greatly, especially the calcium and aluminum elements, which can easily lead to the instability of the glass solid body, and then lead to the difficulty of pouring and the leaching of radioactive elements, which seriously affects the versatility and feasibility of the method; and when the glass solidification method is only for radioactive solid waste of a specific composition, it will inevitably lead to the instability of the solidified product due to the lack of versatility, which is unacceptable; although in the prior art, a certain range of raw materials is usually given, it has been found in practice that within the given range, not any value can obtain a qualified glass solid body, but only under a specific combination of parameters, can a qualified glass solid body be obtained by glass solidification. Therefore, it is necessary to test the composition and content of each batch of incineration ash, and to develop the process conditions of raw material preparation and glass solidification for different batches of incineration ash, which undoubtedly increases the workload and cost of glass solidification of radioactive combustible waste and lacks application feasibility. 3) The incineration ash of radioactive combustible waste often contains mask nose bridges, metal screws and nuts, and other metal objects. If the filter material is not disassembled cleanly, it will be mixed with aluminum foil. However, most existing glass solidification technologies cannot process raw materials containing metal objects, so metal objects need to be removed from the raw materials before glass solidification.

[0004] Therefore, it is crucial to develop a method for vitrification of radioactive incineration ash and contaminated glass fiber filter material, so as to effectively and stably obtain a glass solidified body that meets the disposal requirements under the premise that the composition of the incineration ash fluctuates greatly and the fly ash composition of the contaminated glass fiber filter material is uncertain. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects in the prior art and provide a method for vitrifying radioactive solid waste incineration ash and contaminated glass fiber filter material, which solves a series of defects caused by large fluctuations in composition and content of different batches of radioactive solid waste when the radioactive solid waste incineration ash and contaminated glass fiber filter material are vitrified together.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A method for co-vitrification of radioactive incineration ash and contaminated glass fiber filter material, comprising: using method one or method two to melt and solidify raw materials containing radioactive incineration ash and contaminated glass fiber filter material to prepare a glass solidified body;

[0008] Method 1: The raw material containing radioactive incineration ash and contaminated glass fiber filter material is composed of 0wt% to 30wt% of radioactive incineration ash and 70wt% to 100wt% of contaminated glass fiber filter material, and the melting temperature is 1100wt% to 1400°C;

[0009] Method 2: The raw material containing radioactive incineration ash and contaminated glass fiber filter material is composed of 0wt% to 40wt% radioactive incineration ash, 30wt% to 60wt% contaminated glass fiber filter material and 15wt% to 50wt% additives, and the melting temperature is 900°C to 1300°C. Normally, method 1 is adopted to mix and melt the contaminated glass fiber filter material and radioactive incineration ash for glass solidification, but when there are strict requirements on the anti-leaching property of radionuclides, method 2 is required to be adopted, by adding additives, on the one hand, the temperature of the melting process is reduced to reduce the volatilization of radionuclides, and on the other hand, the content of silicon oxide is increased to ensure that a stable glass solidification body can be formed under the raw material composition with large fluctuations, and the anti-leaching property of radionuclides is reduced.

[0010] As a further technical solution, in method one, when the dust content of the contaminated glass fiber filter material is ≤15wt%, the material compatibility range is: the content of the contaminated glass fiber filter material is ≥70wt%, and the content of the radioactive incineration ash is ≤30wt%; when 15wt%≤the dust content of the contaminated glass fiber filter material≤25wt%, the material compatibility range is: the content of the contaminated glass fiber filter material is ≥80wt%, and the content of the radioactive incineration ash is ≤20wt%; when 25wt%≤the dust content of the contaminated glass fiber filter material≤35wt%, the material compatibility range is: the content of the contaminated glass fiber filter material is ≥90wt%, and the content of the radioactive incineration ash is ≤10wt%.

[0011] As a further technical solution, the contaminated glass fiber filter material is obtained by disassembling and separating radioactive waste nuclear-grade air filters;

[0012] As a further technical solution, the radioactive incineration ash is obtained by incinerating or pyrolyzing radioactive combustible waste.

[0013] As a further technical solution, the radioactive combustible waste includes one or more of waste resin, masks, cotton clothing, gloves, shoes, protective clothing, anti-contamination plastic cloth and rubber gaskets.

[0014] As a further technical solution, the radioactive incineration ash comprises: 20wt% to 65wt% calcium oxide; 0wt% to 25wt% silicon oxide; 0wt% to 25wt% aluminum oxide; 0wt% to 15wt% iron oxide; 0wt% to 15wt% titanium oxide; 0wt% to 10wt% sulfur trioxide; 0wt% to 10wt% chlorine; and 10wt% to 40wt% carbonate in terms of carbon dioxide.

[0015] As a further technical solution, the contaminated glass fiber filter material includes: 30wt% to 60wt% silicon oxide; 2wt% to 15wt% calcium oxide; 0wt% to 25wt% carbonate in terms of carbon dioxide; 3wt% to 15wt% boron oxide; 3wt% to 20wt% sodium oxide; 2wt% to 15wt% aluminum oxide; 0wt% to 10wt% potassium oxide; 0wt% to 9wt% barium oxide; 0wt% to 9wt% zinc oxide;

[0016] As a further technical solution, the thermal ignition loss rate of the radioactive incineration ash is less than 5%;

[0017] As a further technical solution, the content of combustible components in the contaminated glass fiber filter material is less than 15%.

[0018] As a further technical solution, the additive includes 25wt% to 60wt% silicon oxide, 18wt% to 38wt% boron oxide, 5wt% to 13wt% lithium oxide, 7wt% to 15wt% sodium oxide, and 7wt% to 15wt% potassium oxide.

[0019] As a further technical solution, before the radioactive incineration ash and the contaminated glass fiber filter material are melted and solidified, it is necessary to remove the metal objects in the radioactive incineration ash and the contaminated glass fiber filter material, and use a metal detector to detect them to ensure that they are removed completely.

[0020] As a further technical solution, the metal object includes one or more of a metal block (such as a screw, etc.), aluminum foil, and a metal wire (such as an iron wire).

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention limits the amount of radioactive incineration ash, the dust adhesion and amount of the contaminated glass fiber filter material / the composition and amount of additives, the melting temperature, the removal of metal objects in the radioactive solid waste and other process conditions, thereby ensuring that the present invention can effectively and stably obtain a glass solid body that meets the disposal requirements under the premise that the composition of the incineration ash fluctuates greatly and the fly ash composition contained in the contaminated glass fiber filter material is uncertain, thereby realizing the common waste treatment of the radioactive incineration ash obtained by the incineration of combustible radioactive waste and the glass fiber filter material obtained by disassembling the waste filter element. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is the infrared characterization image of Example 1;

[0024] Figure 2 is the XRD characterization diagram of Example 1;

[0025] Figure 3 This is the infrared characterization image of Example 2;

[0026] Figure 4 is the XRD characterization diagram of Example 2;

[0027] Figure 5 This is a photograph of the glass solidified body of Example 5. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] 1. The main components of the raw materials used in the present invention are shown in Table 1, and the metal objects have been removed from the raw materials used.

[0030] Table 1: Main components of incineration ash and contaminated glass fiber filter materials (in wt%)

[0031]

[0032] The dust content of filter material A and filter material B is ≤15wt%;

[0033] The thermal loss rate of incineration ash A, incineration ash B and incineration ash C is less than 5%;

[0034] The combustible component content of the filter material A and the filter material B is less than 15%.

[0035] 2. Unless otherwise specified, the raw materials used in the present invention are commercially available reagents.

[0036] The present invention is described in further detail below with reference to the accompanying drawings.

[0037] Example 1

[0038] Then, take A3g of the incineration ash and A7g of the filter material and place them in a 100ml crucible. Put the crucible into a muffle furnace, heat it to 200°C after 20 minutes, stay for 20 minutes, and then heat it to 1100°C after 100 minutes, and then keep it at the specified temperature for 4 hours to complete the melting. Then cool it with the furnace and drop to room temperature in about 24 hours. XRD characterization and infrared characterization both show that the solidified body is a uniform glass (see Figure 1-Figure 2 ).

[0039] Example 2

[0040] Then, take 3g of the incineration ash A and 7g of the filter material B, and place them in a 100ml crucible. Place the crucible in a muffle furnace, heat it to 200°C after 20min, hold it for 20min, and then heat it to 1200°C after 100min, and then keep it at the specified temperature for 4h to complete the melting. Then cool it with the furnace and drop to room temperature in about 24h. XRD characterization and infrared characterization both show that the solidified body is a homogeneous glass (see Figure 3-Figure 4 ).

[0041] Example 3

[0042] Take 2g of incineration ash B, 4g of filter material A, add 4g of additives (including: 1.5g of silicon oxide, 1.25g of boron oxide, 0.25g of lithium oxide, 0.5g of sodium oxide, 0.5g of potassium oxide), and place them in a 100ml crucible. Put the crucible into a muffle furnace, heat it to 200℃ after 20min, stay for 20min, and then heat it to 1000℃ after 100min, then keep it at the specified temperature for 4h to complete the melting. Then cool it with the furnace and drop to room temperature in about 24h.

[0043] Example 4

[0044] Take 2g of incineration ash C, take 4g of filter material A, add 4g of additives (including: 1g of silicon oxide, 1.5g of boron oxide, 0.5g of lithium oxide, 0.5g of sodium oxide, and 0.5g of potassium oxide), and place them in a 100ml crucible. Put the crucible into a muffle furnace, heat it to 200℃ after 20min, stay for 20min, and then heat it to 1000℃ after 100min, then keep it at the specified temperature for 4h to complete the melting. Then cool it with the furnace and drop to room temperature in about 24h.

[0045] Example 5

[0046] According to the composition ratio of Example 1, 15 g of incineration ash A and 35 g of filter material A were taken, 0.5 g of cesium chloride was added as a simulated radioactive nuclide, and placed in a 200 ml crucible. The crucible was placed in a muffle furnace, heated to 200°C over 20 minutes, kept for 20 minutes, and then heated to 1200°C over 100 minutes. The temperature was kept at this temperature for 4 hours, and then cast in a preheated graphite oil tank, 3 pieces each, and then annealed at 500°C to obtain a glass solid body (see Figure 5 ). The leaching test of the solidified body was carried out using the method of GB / T 7023-2011. The experimental results showed that the cumulative leaching rate did not exceed 4.13×10 -5 cm / d.

[0047] Comparative Example 1

[0048] Take 4g of incineration ash and 6g of filter material B, and place them in a 100ml crucible. Put the crucible into a muffle furnace, heat it to 200℃ after 20min, stay for 20min, and then heat it to 1200℃ after 100min, and then keep it at the specified temperature for 4h to complete the melting. Then cool it with the furnace and drop to room temperature in about 24h. There is a lot of white unmelted material in the middle of the solidified body, and it is impossible to form a uniform glass solidified body.

[0049] Comparative Example 2:

[0050] Take the incineration ash B4g and the filter material B6g, and place them in a 100ml crucible. Put the crucible into a muffle furnace, heat it to 200℃ after 20min, stay for 20min, and then heat it to 1200℃ after 100min, and then keep it at the specified temperature for 4h to complete the melting. Then cool it with the furnace and drop to room temperature in about 24h. A large number of flaky stones appear in the solidified body, and there is serious crystallization.

[0051] Comparative Example 3

[0052] Take 9g of filter material A and 1g of aluminum foil (obtained from disassembling the high-efficiency filter core) and place them in a 100ml crucible. Place the crucible in a muffle furnace, heat it to 200°C after 20 minutes, stay for 20 minutes, and then heat it to 1200°C after 100 minutes, then keep it at the specified temperature for 4 hours to complete the melting. Then cool it with the furnace and drop to room temperature in about 24 hours. White foam appears on the surface of the solidified body, which is the oxidation of metal aluminum to aluminum oxide, and it is impossible to form a uniform glass solidified body.

[0053] Comparative Example 4

[0054] Take 7g of incineration ash B and 3g of filter material A, and place them in a 100ml crucible. Place the crucible in a muffle furnace, heat it to 200°C after 20 minutes, stay for 20 minutes, and then heat it to 1200°C after 100 minutes, and then keep it at the specified temperature for 4 hours to complete the melting. Then cool it with the furnace and drop to room temperature in about 24 hours. The solidified body is an inhomogeneous substance, and no glass solidified body can be obtained.

[0055] Comparative Example 5

[0056] Take 8g of incineration ash B and 2g of filter material A, and place them in a 100ml crucible. Place the crucible in a muffle furnace, heat it to 200°C after 20min, hold it for 20min, and then heat it to 1200°C after 100min, and then keep it at the specified temperature for 4h to complete the melting. Then cool it with the furnace and drop it to room temperature in about 24h. The solidified body is an inhomogeneous substance, and no glass solidified body can be obtained.

[0057] Comparative Example 6

[0058] Take 9g of incineration ash B and 1g of filter material A, and place them in a 100ml crucible. Place the crucible in a muffle furnace, heat it to 200°C after 20min, hold it for 20min, and then heat it to 1200°C after 100min, then keep it at the specified temperature for 4h to complete the melting. Then cool it with the furnace and drop it to room temperature in about 24h. The solidified body is an inhomogeneous substance, and no glass solidified body can be obtained.

[0059] The above-described embodiments are only preferred embodiments of the present invention, and are not exhaustive of the feasible implementations of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A method for co-vitrification of radioactive incineration ash and contaminated glass fiber filter material, characterized in that: Using method 1 or method 2, raw materials containing radioactive incineration ash and contaminated glass fiber filter material are melted and solidified to prepare a glass solidified body; wherein, Method 1: The raw material containing radioactive incineration ash and contaminated glass fiber filter material is composed of 0wt% to 30wt% of radioactive incineration ash and 70wt% to 100wt% of contaminated glass fiber filter material, and the melting temperature is 1100° C. to 1400° C.; Method 2: The raw material containing radioactive incineration ash and contaminated glass fiber filter material consists of 0wt% to 40wt% of radioactive incineration ash, 30wt% to 60wt% of contaminated glass fiber filter material and 15wt% to 50wt% of additives, and the melting temperature is 900°C to 1300°C.

2. A method for co-vitrification of radioactive incineration ash and contaminated glass fiber filter material according to claim 1, characterized in that: In method one, when the dust content of the contaminated glass fiber filter material is ≤15wt%, the material compatibility range is: the content of the contaminated glass fiber filter material is ≥70wt%, and the content of the radioactive incineration ash is ≤30wt%; when 15wt%≤the dust content of the contaminated glass fiber filter material≤25wt%, the material compatibility range is: the content of the contaminated glass fiber filter material is ≥80wt%, and the content of the radioactive incineration ash is ≤20wt%; when 25wt%≤the dust content of the contaminated glass fiber filter material≤35wt%, the material compatibility range is: the content of the contaminated glass fiber filter material is ≥90wt%, and the content of the radioactive incineration ash is ≤10wt%.

3. A method for co-vitrification of radioactive incineration ash and contaminated glass fiber filter material according to claim 1, characterized in that: The contaminated glass fiber filter material is obtained by disassembling and separating radioactive waste nuclear-grade air filters; and the radioactive incineration ash is obtained by incinerating or pyrolyzing radioactive combustible waste.

4. A method for co-vitrification of radioactive incineration ash and contaminated glass fiber filter material according to claim 3, characterized in that: The radioactive combustible waste includes one or more of waste resin, masks, cotton clothing, gloves, shoes, protective clothing, anti-contamination plastic cloth and rubber gaskets.

5. A method for co-vitrification of radioactive incineration ash and contaminated glass fiber filter material according to claim 1, characterized in that: The radioactive incineration ash comprises: 20wt% to 65wt% calcium oxide; 0wt% to 25wt% silicon oxide; 0wt% to 25wt% aluminum oxide; 0wt% to 15wt% iron oxide; 0wt% to 15wt% titanium oxide; 0wt% to 10wt% sulfur trioxide; 0wt% to 10wt% chlorine; and 10wt% to 40wt% carbonate in terms of carbon dioxide.

6. A method for co-vitrification of radioactive incineration ash and contaminated glass fiber filter material according to claim 1, characterized in that: The contaminated glass fiber filter material includes: 30wt% to 60wt% silicon oxide; 2wt% to 15wt% calcium oxide; 0wt% to 25wt% carbonate in terms of carbon dioxide; 3wt% to 15wt% boron oxide; 3wt% to 20wt% sodium oxide; 2wt% to 15wt% aluminum oxide; 0wt% to 10wt% potassium oxide; 0wt% to 9wt% barium oxide; and 0wt% to 9wt% zinc oxide.

7. A method for co-vitrification of radioactive incineration ash and contaminated glass fiber filter material according to claim 1, characterized in that: The thermal ignition loss rate of the radioactive incineration ash is less than 5%, and the content of combustible components of the contaminated glass fiber filter material is less than 15%.

8. A method for co-vitrification of radioactive incineration ash and contaminated glass fiber filter material according to claim 1, characterized in that: The additives include 25wt% to 60wt% of silicon oxide, 18wt% to 38wt% of boron oxide, 5wt% to 13wt% of lithium oxide, 7wt% to 15wt% of sodium oxide, and 7wt% to 15wt% of potassium oxide.

9. A method for co-vitrification of radioactive incineration ash and contaminated glass fiber filter material according to claim 1, characterized in that: Before the radioactive incineration ash and contaminated glass fiber filter material are melted and solidified, metal objects in the radioactive incineration ash and contaminated glass fiber filter material must be removed and detected with a metal detector to ensure that they are completely removed.

10. A method for co-vitrification of radioactive incineration ash and contaminated glass fiber filter material according to claim 9, characterized in that: The metal object includes one or more of a metal block, an aluminum foil, and a metal wire.

Images