Oxiding compositions, methods of making thereof, uses thereof and methods of use thereof

Abstract

The present disclosure provides an oxidizing composition comprising a volatile acid having oxidizing properties, hydrogen peroxide, an optional volatile acid having complexing properties, and a solvent. The invention also provides a preparation method and application of the oxidation composition and a method for treating an irradiation target containing radioactive substances by using the oxidation composition.

Description

Technical Field

[0001] The present disclosure relates to oxidizing compositions, and more particularly to compositions for oxidizing irradiated targets containing radioactive materials, preferably containing 14 The present invention also relates to a composition for irradiating a target material of C. The present invention also relates to a preparation method of the composition and a method for using the composition. Background Art

[0002] The production of radioactive materials is mainly achieved by irradiating target materials. For example, typically, 14 The production of C is mainly through the thermal neutron irradiation of aluminum nitride target in a nuclear reactor, which causes the nitrogen in the aluminum nitride to generate 14 N(n,p) 14 C reaction produces 14 C, and then under the action of oxidant, the generated 14 C 14 It is released in the form of CO2, and then absorbed by sodium hydroxide, precipitated by barium chloride salt, filtered, washed and dried to obtain barium carbonate- 14 C product.

[0003] In the prior art, the principles of the methods for treating irradiated targets are similar, mainly focusing on converting radioactive substances such as 14 C release method from the target material. According to the state of the extractant used, it can be divided into dry method and wet method. The wet method uses liquid oxidant or hydrolysis liquid to remove radioactive substances in the target material, such as 14 C is released, and this method has the advantages of being able to operate in large quantities, relatively thorough reaction of the target material, and relatively high extraction rate of radioactive substances. However, the oxidation efficiency of the liquid oxidant or hydrolyzate in the traditional wet method is still not high enough (by-products are easily generated) and due to the addition of a large amount of liquid oxidizing liquid (in order to allow the target material to fully react, the amount of oxidizing liquid or hydrolyzate added far exceeds the amount of target material, but the oxidizing liquid or hydrolyzate is often not volatile), the amount of radioactive waste increases significantly compared to the dry method, increasing the subsequent waste treatment costs.

[0004] Therefore, existing methods for processing irradiation targets containing radioactive substances still need to be improved. Summary of the invention

[0005] As mentioned above, in the prior art, when treating irradiated target materials, whether using an oxidant or an acidic hydrolysis solution, a non-volatile inorganic acid is required, so that the mother liquor after treatment is a radioactive waste liquid containing a large amount of acid liquid. Direct solidification will cause the amount of radioactive waste to increase seriously, and the cost will increase rapidly. In addition, when using inorganic acid hydrolysis, it is necessary to use oxide metal for oxidation later, which increases the treatment process and steps, making the treatment process too cumbersome.

[0006] The present disclosure is made in view of the above-mentioned problems, and its purpose is to improve the oxidation efficiency by preparing a fully volatile and highly oxidizing oxidative hydrolysis solution to quickly oxidize and treat the target material without the need for a subsequent secondary oxidation process. At the same time, since the prepared oxidative hydrolysis solutions are all volatile inorganic compounds, after the oxidation is completed, the oxidative mother liquor can be concentrated and solidified by means of reduced pressure distillation, and the high-level radioactive waste can be conveniently processed into solids, and a large amount of low-level radioactive waste can be separated from the high-level radioactive waste, thereby achieving the purpose of reducing the amount of high-level radioactive waste. The amount of waste after treatment is basically at the same level as that of dry treatment, but its oxidation efficiency and equipment requirements are lower than those of dry and traditional wet methods. As a result, it is possible to improve the oxidation efficiency on the one hand, and on the other hand effectively solve the problems of complex post-processing process, large amount of radioactive waste and high cost existing in the traditional wet process.

[0007] In order to achieve the above object, the first aspect of the present disclosure provides an oxidizing composition comprising:

[0008] Volatile acids with oxidizing properties;

[0009] Hydrogen peroxide;

[0010] optionally a volatile acid having complexing properties; and

[0011] Solvent.

[0012] In one embodiment, in the composition of the first aspect, based on 100 parts by weight of the solvent, the content of the oxidizing volatile acid is 10-120 parts by weight, preferably 20-100 parts by weight, more preferably 40-80 parts by weight, further preferably 50-70 parts by weight, most preferably 62 parts by weight, and / or

[0013] Based on 100 parts by weight of the solvent, the content of the hydrogen peroxide is 5-50 parts by weight, preferably 10-40 parts by weight, more preferably 20-30 parts by weight, most preferably 21 parts by weight, and / or

[0014] Based on 100 parts by weight of the solvent, the content of the complexing volatile acid is 0-30 parts by weight, preferably 5-20 parts by weight, more preferably 10-15 parts by weight, and most preferably 14 parts by weight.

[0015] In one embodiment, in the composition of the first aspect, the volatile acid having oxidizing properties is nitric acid; and / or

[0016] The volatile acid with complexing property is hydrofluoric acid and / or hydrochloric acid; and / or

[0017] The solvent is an aqueous solvent and / or an ionic liquid, preferably water.

[0018] A second aspect of the present disclosure provides a method for preparing an oxidizing composition, comprising mixing the following components:

[0019] Volatile acids with oxidizing properties;

[0020] Hydrogen peroxide;

[0021] optionally a volatile acid having complexing properties; and

[0022] Solvent.

[0023] In one embodiment, in the method of the second aspect, based on 100 parts by weight of the solvent, the content of the oxidizing volatile acid is 10-120 parts by weight, preferably 20-100 parts by weight, more preferably 40-80 parts by weight, further preferably 50-70 parts by weight, most preferably 62 parts by weight, and / or

[0024] Based on 100 parts by weight of the solvent, the content of the hydrogen peroxide is 5-50 parts by weight, preferably 10-40 parts by weight, more preferably 20-30 parts by weight, most preferably 21 parts by weight, and / or

[0025] Based on 100 parts by weight of the solvent, the content of the complexing volatile acid is 0-30 parts by weight, preferably 5-20 parts by weight, more preferably 10-15 parts by weight, and most preferably 14 parts by weight.

[0026] In one embodiment, in the method of the second aspect, the volatile oxidizing acid is nitric acid; and / or

[0027] The volatile acid with complexing property is hydrofluoric acid and / or hydrochloric acid; and / or

[0028] The solvent is an aqueous solvent and / or an ionic liquid, preferably water.

[0029] The third aspect of the present disclosure provides an oxidation composition according to the first aspect or an oxidation composition prepared by the method according to the second aspect for use in oxidizing an irradiated target material containing a radioactive substance, preferably containing 14 C irradiated target material and / or irradiated target material containing radioactive material for cracking and filling, preferably containing 14 Use of metal shell of irradiated target material of C.

[0030] In one embodiment, in the use of the third aspect, the 14 The irradiated target material of C is selected from one or more of the following groups: irradiated aluminum nitride, irradiated magnesium nitride, irradiated silicon nitride, irradiated calcium nitride and irradiated beryllium nitride, preferably irradiated aluminum nitride.

[0031] A fourth aspect of the present disclosure provides a method for treating an irradiation target material containing a radioactive substance, comprising:

[0032] (1) contacting an irradiated target material containing a radioactive substance with the oxidizing composition according to the first aspect or the oxidizing composition prepared by the method according to the second aspect to carry out an oxidation reaction to produce a gas phase product containing a radioactive substance; and

[0033] (2) Optionally, the solution obtained after the reaction in step (1) is subjected to solid-liquid separation.

[0034] In one embodiment, in the method of the fourth aspect, the irradiation target material containing radioactive material is 14 C irradiation target material, and preferably, the 14 The irradiated target material of C is selected from one or more of the following groups: irradiated aluminum nitride, irradiated magnesium nitride, irradiated silicon nitride, irradiated calcium nitride and irradiated beryllium nitride, preferably irradiated aluminum nitride.

[0035] In one embodiment, in step (1), the volume / weight ratio of the oxidizing composition to the irradiated target material containing the radioactive substance is 0.5-100 mL / g; and / or

[0036] The step (1) is carried out at a temperature of -30 to 100°C.

[0037] In one embodiment, the step (1) comprises: adding the irradiated target material containing the radioactive substance to the oxidizing composition under optional stirring, and preferably, the step (1) is carried out at a temperature of -20 to 100°C, preferably 0 to 80°C, more preferably 20 to 60°C, further preferably 30 to 40°C, and most preferably 35°C, and further, when the oxidizing composition in the step (1) contains hydrochloric acid, the step (1) is carried out at a temperature of -20 to 60°C, preferably 0 to 40°C.

[0038] In one embodiment, the step (1) comprises: adding the oxidizing composition, preferably dropping it into the irradiated target material containing the radioactive substance, optionally under stirring, and preferably, the step (1) is carried out at a temperature of -30 to 60°C, preferably -20 to 30°C, and further, when the oxidizing composition in the step (1) contains hydrochloric acid, the step (1) is carried out at a temperature of -30 to 50°C, preferably -25 to 25°C.

[0039] In one embodiment, the solid-liquid separation treatment in step (2) is performed by distillation, preferably reduced pressure distillation. DETAILED DESCRIPTION

[0040] The embodiments of the present disclosure are described in detail as appropriate below. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there may be cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structure are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the following description is provided for those skilled in the art to fully understand the present disclosure and is not intended to limit the subject matter described in the claims.

[0041] "Scope" in the present disclosure is defined in the form of lower limit and upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope defined in this way can include or exclude end values, and can be combined arbitrarily, that is, any lower limit can form a scope with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for a particular parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 listed, and if the maximum range values ​​3,4 and 5 are listed, the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present disclosure, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed in this article, and "0-5" is just an abbreviation of these numerical combinations.

[0042] The terms "first", "second" and the like used in the present disclosure are used only to distinguish between objects for the sake of clarity of description, and do not limit the size, quantity or other order of the objects described therein.

[0043] If not otherwise specified, all embodiments and optional embodiments of the present disclosure may be combined with each other to form a new technical solution.

[0044] Unless otherwise stated, the words “comprises,” “includes,” “has,” “contains” or any other variations thereof mentioned in the present disclosure are intended to cover a non-exclusive inclusion.

[0045] If there is no special explanation, the indefinite articles "a" and "an" before the elements or components in the present disclosure have no limitation on the quantity requirements (i.e. the number of occurrences) of the elements or components. Therefore, "a" or "an" should be interpreted as including one or at least one, and the elements or components in the singular form also include the plural form, unless the number is obviously intended to be limited to the singular form.

[0046] Further, in the following specification, reference will be made to a number of expressions, which are defined as having the following meanings.

[0047] the term" 14 "C", also known as "Carbon-14", is a radioactive isotope of carbon.

[0048] The term "reduced pressure distillation" refers to the separation under reduced pressure of substances that are difficult to separate when heated to boiling under normal pressure.

[0049] The term "volatile acid having oxidizing property" refers to an acid having both oxidizing property and volatility to the irradiated target material.

[0050] The term "volatile acid having complexing property" refers to an acid having both complexing property and volatility to metal ions in the irradiated target material.

[0051] The term "nitric acid" refers only to pure HNO3, not its solutions.

[0052] The term "hydrogen peroxide" refers only to pure H2O2, not its solutions.

[0053] The term "hydrofluoric acid" refers only to pure HF, not its solutions.

[0054] The term "hydrochloric acid" refers only to pure HCl, not its solutions.

[0055] As mentioned above, the irradiated target material containing radioactive substances used in the prior art preferably contains 14 The composition and method of irradiated target materials of C still have problems such as low oxidation efficiency, many by-products, complex post-processing process, large amount of radioactive waste and high cost, which need to be solved urgently.

[0056] Oxidation Composition

[0057] In order to at least partially solve the above problems and one or more of other potential problems, a first exemplary embodiment of the present disclosure provides an oxidizing composition comprising:

[0058] Volatile acids with oxidizing properties;

[0059] Hydrogen peroxide;

[0060] optionally a volatile acid having complexing properties; and

[0061] Solvent.

[0062] There is no particular limitation on the specific type of the "oxidizing volatile acid" as long as the acid has both oxidizing and volatile properties. Typically, the oxidizing volatile acid is nitric acid.

[0063] The amount of the "volatile acid having oxidizing properties" can be 10-120 parts by weight, based on 100 parts by weight of the solvent, for example, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66,

[0064] Regarding the amount of "hydrogen peroxide", based on 100 parts by weight of the solvent content, it can be 5-50 parts by weight, for example, it can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50 parts by weight or any value between these values, but preferably 10-40 parts by weight, more preferably 20-30 parts by weight, and most preferably 21 parts by weight.

[0065] There is no particular limitation on the specific type of the "volatile acid with complexing property", as long as the acid has both complexing property and volatility. Typically, the volatile acid with complexing property is hydrofluoric acid and / or hydrochloric acid.

[0066] Regarding the amount of "volatile acid with complexing properties", based on 100 parts by weight of the solvent, it can be 0-30 parts by weight, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 parts by weight or any number therebetween, but preferably 5-20 parts by weight, more preferably 10-15 parts by weight, and most preferably 14 parts by weight.

[0067] There is no particular limitation on the specific type of "solvent", as long as it can effectively dissolve the volatile acid with oxidizing property, hydrogen peroxide and the volatile acid with complexing property without causing side reactions that substantially affect the oxidizing properties of the composition. Typically, the solvent is an aqueous solvent and / or an ionic liquid, preferably water.

[0068] The above-mentioned oxidizing composition exists in the form of a volatile oxidizing hydrolyzate, has a high-efficiency oxidizing ability, and can achieve rapid oxidation at low temperature. 14 C irradiates the target material, and no secondary reoxidation process is required. The highly efficient oxidative hydrolysate can be used to rapidly 14 C irradiated target 14 Oxidation of C 14 The CO2 gas is then discharged with the carrier gas and separated from the oxidized hydrolyzate, while the remaining strong gamma-ray nuclides remain in the hydrolyzate. However, the traditional dry method requires high-temperature oxidation, which places high demands on the processing equipment and also produces a large amount of nitrogen oxides, which will bring difficulties to subsequent processing. The high-efficiency oxidized hydrolyzate disclosed in the present invention can efficiently oxidize nitrogen oxides at a temperature of -30-100°C. 14 C irradiates the target material, and at the same time, the nitride in the target material is oxidized into harmless substances such as nitrogen, and only a very small amount of nitrogen oxides is generated, which greatly simplifies the subsequent treatment process. In addition, in order to solve the problem of high-level radioactive waste, including the oxidation and decomposition process of the target material, the traditional wet method will produce a large amount of high-level radioactive waste, that is, 14 C target material and oxidative hydrolysate or acidic hydrolysate mixture of high-level radioactive waste. Since traditional oxidative hydrolysate or acidic hydrolysate contains a large amount of non-volatile inorganic acids such as sulfuric acid, phosphoric acid, etc., if these wastes are subjected to volume reduction treatment, these strong acids must be neutralized, and alkali needs to be further added, which increases the amount of waste. The present invention uses a volatile inorganic acid to form a composition for oxidation, which will not increase the amount of additional waste. After the reaction is completed, it can be directly distilled to reduce the volume without adding alkali to the target material for treatment. In this way, the highly radioactive waste is solidified, and a very small amount or exempt liquid is separated from the radioactive mother liquor, which greatly reduces the cost of waste treatment.

[0069] Method for preparing oxidizing composition

[0070] In order to at least partially solve the above problems and one or more of other potential problems, a second exemplary embodiment of the present disclosure provides a method for preparing an oxidizing composition, which includes mixing the following components:

[0071] Volatile acids with oxidizing properties;

[0072] Hydrogen peroxide;

[0073] optionally a volatile acid having complexing properties; and

[0074] Solvent.

[0075] There is no particular limitation on the specific type of the "oxidizing volatile acid" as long as the acid has both oxidizing and volatile properties. Typically, the oxidizing volatile acid is nitric acid.

[0076] The amount of the "volatile acid having oxidizing properties" can be 10-120 parts by weight, based on 100 parts by weight of the solvent, for example, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66,

[0077] Regarding the amount of "hydrogen peroxide", based on 100 parts by weight of the solvent content, it can be 5-50 parts by weight, for example, it can be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50 parts by weight or any value between these values, but preferably 10-40 parts by weight, more preferably 20-30 parts by weight, and most preferably 21 parts by weight.

[0078] There is no particular limitation on the specific type of the "volatile acid with complexing property", as long as the acid has both complexing property and volatility. Typically, the volatile acid with complexing property is hydrofluoric acid and / or hydrochloric acid.

[0079] Regarding the amount of "volatile acid with complexing properties", based on 100 parts by weight of the solvent, it can be 0-30 parts by weight, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 parts by weight or any number therebetween, but preferably 5-20 parts by weight, more preferably 10-15 parts by weight, and most preferably 14 parts by weight.

[0080] There is no particular limitation on the specific type of "solvent", as long as it can effectively dissolve the volatile acid with oxidizing property, hydrogen peroxide and the volatile acid with complexing property without causing side reactions that substantially affect the oxidizing properties of the composition. Typically, the solvent is an aqueous solvent and / or an ionic liquid, preferably water.

[0081] There is no particular limitation on the specific method of "mixing". The volatile acid with oxidizing properties, hydrogen peroxide, optional volatile acid with complexing properties and solvent can be directly mixed. The volatile acid with oxidizing properties and / or hydrogen peroxide and / or volatile acid with complexing properties can be first dissolved in the solvent and then mixed, or other possible methods can be used.

[0082] Use of oxidizing compositions

[0083] In order to at least partially solve one or more of the above-mentioned problems and other potential problems, the third exemplary embodiment of the present disclosure provides an oxidizing composition according to the above-mentioned first exemplary embodiment or an oxidizing composition prepared by the method according to the above-mentioned second exemplary embodiment for oxidizing an irradiated target material containing radioactive material and / or for cracking a metal casing of a device loaded with the irradiated target material containing radioactive material.

[0084] There is no particular limitation on the "irradiation target material containing radioactive substances", and it can be those commonly used in the art, for example, preferably containing 14 C irradiation target.

[0085] About "Including 14 The "irradiated target material of C" is not particularly limited and can be those commonly used in the art, for example, one or more selected from the following group: irradiated aluminum nitride, irradiated magnesium nitride, irradiated silicon nitride, irradiated calcium nitride and irradiated beryllium nitride, but preferably irradiated aluminum nitride.

[0086] There is no particular limitation on the "metal casing of the device for loading the irradiation target material containing radioactive substances", and it can be those commonly used in the art, such as stainless steel, aluminum, zirconium, iron, cobalt, nickel, chromium, copper, lead and other metals.

[0087] Methods of using the oxidizing composition

[0088] In order to at least partially solve the above problems and one or more of other potential problems, a fourth exemplary embodiment of the present disclosure provides a method for processing an irradiation target material containing a radioactive substance, comprising:

[0089] (1) contacting an irradiated target material containing a radioactive substance with the oxidizing composition described in the first exemplary embodiment or the oxidizing composition prepared by the method described in the second exemplary embodiment to carry out an oxidation reaction to produce a gas phase product containing a radioactive substance; and

[0090] (2) Optionally, the solution obtained after the reaction in step (1) is subjected to solid-liquid separation.

[0091] There is no particular limitation on the "irradiation target material containing radioactive substances", and it can be those commonly used in the art, for example, preferably containing 14 C irradiation target.

[0092] About "Including 14 The "irradiated target material of C" is not particularly limited and can be those commonly used in the art, for example, one or more selected from the following group: irradiated aluminum nitride, irradiated magnesium nitride, irradiated silicon nitride, irradiated calcium nitride and irradiated beryllium nitride, but preferably irradiated aluminum nitride.

[0093] The dosage of the oxidation composition and the irradiation target material containing radioactive substances can be adjusted according to actual conditions, for example, a volume / weight ratio of 0.5-100 mL / g is adopted.

[0094] The temperature used for implementing the step (1) can be -30 to 100°C, for example -30°C, -29°C, -28°C, -27°C, -26°C, -25°C, -24°C, -23°C, -22°C, -21°C, -20°C, -19°C, -18°C, -17°C, -16°C, -15°C, -14°C, -13°C, -12°C, -11°C, -10°C , -9℃, -8℃, -7℃, -6℃, -5℃, -4℃, -3℃, -2℃, -1℃, 0℃, 1℃, 2℃, 3℃, 4℃, 5℃, 6℃, 7℃, 8℃, 9℃, 10℃, 11℃, 12℃, 13℃, 14℃, 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 2 7℃、28℃、29℃、30℃、31℃、32℃、33℃、34℃、35℃、36℃、37℃、38℃、39℃、40℃、41℃、42℃、43℃、44℃、45℃、46℃、47℃、48℃、49℃、50℃、51℃、52℃、53℃、54℃、55℃、56℃、57℃、58℃、59℃、60℃、6 ℃, 100℃, 110℃, 111℃, 112℃, 113℃, 114℃, 115℃, 116℃, 117℃, 118℃, 119℃, 120℃, 121℃, 122℃, 123℃, 124℃, 125℃, 126℃, 127℃, 128℃, 129℃, 130℃, 131℃, 132℃, 133℃, 134℃, 135℃, 136℃, 137℃, 138℃, 139℃, 140℃, 141℃, 142℃, 143℃, 144℃, 145℃, 146℃, 147℃, 148℃,

[0095] There is no particular limitation on the specific manner of contacting the irradiated target material containing the radioactive substance with the oxidizing composition in the step (1), and for example, the manner may include: adding the irradiated target material containing the radioactive substance to the oxidizing composition under optional stirring, or may include: adding, preferably dropwise adding, the oxidizing composition to the irradiated target material containing the radioactive substance under optional stirring.

[0096] When the irradiated target material containing radioactive material is added to the oxidizing composition, preferably, the step (1) is carried out at a temperature of -20 to 100°C, for example, -20°C, -19°C, -18°C, -17°C, -16°C, -15°C, -14°C, -13°C, -12°C, -11°C, -10°C, -9°C, -8°C, -7°C, -6°C, -5°C, -4°C , -3℃, -2℃, -1℃, 0℃, 1℃, 2℃, 3℃, 4℃, 5℃, 6℃, 7℃, 8℃, 9℃, 10℃, 11℃, 12℃, 13℃, 14℃, 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, 30℃, 31℃, 32℃, 33℃, 34℃ ℃、35℃、36℃、37℃、38℃、39℃、40℃、41℃、42℃、43℃、44℃、45℃、46℃、47℃、48℃、49℃、50℃、51℃、52℃、53℃、54℃、55℃、56℃、57℃、58℃、59℃、60℃、61℃、62℃、63℃、64℃、65℃、66℃、67℃、68℃、69 ℃, 70℃, 71℃, 72℃, 73℃, 74℃, 75℃, 76℃, 77℃, 78℃, 79℃, 80℃, 81℃, 82℃, 83℃, 84℃, 85℃, 86℃, 87℃, 88℃, 89℃, 90℃, 100℃ or any value therebetween, but preferably 0 to 80℃, more preferably 20 to 60℃, further preferably 30 to 40℃, and most preferably 35℃. Further, when the oxidizing composition in step (1) comprises hydrochloric acid, step (1) is carried out at a temperature of -20 to 60°C, for example, -20°C, -19°C, -18°C, -17°C, -16°C, -15°C, -14°C, -13°C, -12°C, -11°C, -10°C, -9°C, -8°C, -7°C, -6°C, -5°C, -4°C, -3°C, -2°C, -1°C, 0°C, 1°C, 2°C, 3°C, 4°C, 5°C, 6°C, 7°C, 8°C, 9°C, 10°C, 11°C, 12°C, 13°C, 14°C, 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C, 44°C ℃, 52℃, 53℃, 54℃, 55℃, 56℃, 57℃, 58℃, 59℃, 60℃ or any value therebetween, but preferably 0 to 40℃.

[0097] When the oxidizing composition is added, preferably dropwise, to the irradiated target material containing the radioactive substance under optional stirring, preferably, the step (1) is carried out at a temperature of -30 to 60°C, for example, -30°C, -29°C, -28°C, -27°C, -26°C, -25°C, -24°C, -23°C, -22°C, -21°C, -20°C, -19°C, -18°C, -17°C, -16°C, -15°C, -14°C, -13°C, -12°C, -11°C, -10°C, -9°C, -8°C, -7°C, -6°C, -5°C, -4°C, -3°C, -2°C, -1°C, 0°C, 1°C, 2°C, 3°C, 4°C, 5°C, 6°C, ℃, 7℃, 8℃, 9℃, 10℃, 11℃, 12℃, 13℃, 14℃, 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, 30℃, 31℃, 32℃, 33℃, 34℃, 35℃, 36℃, 37℃, 38℃, 39℃, 40℃, 41℃, 42℃, 43℃, 44℃, 45℃, 46℃, 47℃, 48℃, 49℃, 50℃, 51℃, 52℃, 53℃, 54℃, 55℃, 56℃, 57℃, 58℃, 59℃, 60℃ or any value between these values, but preferably -20 to 30℃. Further, when the oxidizing composition in step (1) comprises hydrochloric acid, step (1) is carried out at a temperature of -30 to 50°C, for example, -30°C, -29°C, -28°C, -27°C, -26°C, -25°C, -24°C, -23°C, -22°C, -21°C, -20°C, -19°C, -18°C, -17°C, -16°C, -15°C, -14°C, -13°C, -12°C, -11°C, -10°C, -9°C, -8°C, -7°C, -6°C, -5°C, -4°C, -3°C, -2°C, -1°C, 0°C, 1°C, 2°C, 3°C , 4°C, 5°C, 6°C, 7°C, 8°C, 9°C, 10°C, 11°C, 12°C, 13°C, 14°C, 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, 50°C or any value between these values, but preferably -25 to 25°C. Preferably, the entire dropwise addition process is stirred to better control the heat release.

[0098] There is no particular limitation on the solid-liquid separation in step (2), and the separation may be carried out in a conventional manner in the art, such as by distillation, preferably by reduced pressure distillation.

[0099] In the above two oxidation methods, choosing the right temperature can better reduce the generation of nitrogen oxides, thereby ensuring that a very small amount of nitrogen oxides are produced, and the rest will be produced in the form of nitrogen, reducing the subsequent 14 Separation and processing of CO2.

[0100] because 14 C is a radioactive nuclide. At the same time, the irradiated target material will contain a large amount of nuclides with high radiation doses, such as strong gamma rays. 60 Co, etc. Therefore, in the process of treatment, it is necessary to consider both the protection requirements and the collection and treatment of the waste after treatment. After oxidation treatment by the above-mentioned treatment method disclosed in the present invention, all the highly radioactive wastes are concentrated in the oxidation mother liquor, and mainly exist in the form of metal ions. In addition, the amount of oxidation hydrolyzate can be increased at will during the oxidation process without any impact on subsequent treatment. At the same time, no large amount of nitrogen oxides will be generated during oxidation, which is very beneficial to 14 Subsequent purification and absorption of C. The oxidized mother liquor can be directly distilled to reduce its volume. Since highly radioactive wastes exist in the form of metals, and after oxidation and hydrolysis, the components in the mother liquor are mainly nitrates and unreacted nitric acid, hydrofluoric acid and other volatile acids. Excess hydrogen peroxide will decompose into water and oxygen under the catalysis of heavy metal ions. The mother liquor can then be solidified into waste residue by vacuum distillation. The distillate is a solution of dilute nitric acid containing a small amount of hydrofluoric acid or hydrochloric acid. The waste residue is mainly highly radioactive waste, and its total amount is slightly higher than the weight of the original target material, which is basically the same as the weight of dry oxidation. The distillate mainly contains a small amount of 14 C, whose radioactivity level is very low radioactive waste liquid or reaches the exemption level. This realizes the direct conversion of high-level radioactive waste into solid and the separation of very low or exempted oxidizing liquid from high-level radioactive waste, achieving the purpose of optimizing waste treatment.

[0101] The oxidation composition and treatment method proposed in the present disclosure can ensure efficient oxidation, reduce the generation of by-products as much as possible, reduce the complexity of the post-treatment process, and thus effectively reduce costs and improve efficiency.

[0102] Hereinafter, embodiments of the present disclosure are described. The embodiments described below are exemplary and are only used to explain the present disclosure, and should not be construed as limiting the present disclosure. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in the art or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be obtained commercially.

[0103] Example 1

[0104] Preparation of oxidation composition

[0105] 40 mL of nitric acid solution (mass fraction 69%, prepared from nitric acid and water) is placed in a plastic beaker and cooled to 0°C, then 40 mL of hydrogen peroxide solution (mass fraction 30%, prepared from hydrogen peroxide and water) which has been cooled to 0°C in advance is slowly added thereto at low temperature, and after being fully stirred, 20 mL of hydrofluoric acid solution (mass fraction 40%, prepared from hydrofluoric acid and water) which has been cooled to 0°C in advance is added to the mixed solution, and after being fully stirred, the mixture is allowed to stand at low temperature for use. In the oxidizing composition, 62 g of nitric acid, 21 g of hydrogen peroxide and 14 g of hydrofluoric acid are contained in every 100 g of water.

[0106] Processing 14 C irradiation target

[0107] 50 ml of the above oxidation composition was placed in a tetrafluoroethylene reaction bottle and maintained at 35° C. Then, 10 g of aluminum nitride target material was slowly added thereto under stirring to carry out oxidation reaction and the mixed gas generated after oxidation was passed through a quantitative acidic potassium permanganate solution and a sodium hydroxide absorption liquid in sequence. The content of nitrogen oxides generated by the oxidation reaction was determined based on the amount of potassium permanganate solution consumed, and the effect of the oxidation composition on the target material was determined based on the amount of carbon dioxide absorbed by the sodium hydroxide absorption liquid. 14 After the oxidation is completed, the remaining oxidation solution is directly subjected to reduced pressure distillation to obtain the residual solid after oxidation.

[0108] Example 2

[0109] The method is basically the same as Example 1, except that the ratio of each component in the oxidizing composition is adjusted so that the composition is composed of: 10 g of nitric acid and 5 g of hydrogen peroxide per 100 g of water.

[0110] Example 3

[0111] The method is basically the same as Example 1, except that the ratio of each component in the oxidizing composition is adjusted so that the oxidizing composition is composed of: 120 g nitric acid, 40 g hydrogen peroxide, and 30 g hydrofluoric acid per 100 g water.

[0112] Example 4

[0113] The method is basically the same as Example 1, except that the ratio of each component in the oxidizing composition is adjusted so that the composition is composed of: 40 g of nitric acid and 10 g of hydrogen peroxide per 100 g of water.

[0114] Example 5

[0115] The method is basically the same as Example 1, except that the ratio of each component in the oxidizing composition is adjusted so that the oxidizing composition is composed of: 40 g nitric acid, 10 g hydrogen peroxide and 10 g hydrofluoric acid in every 100 g water.

[0116] Example 6

[0117] The method is basically the same as Example 1, except that the ratio of each component in the oxidizing composition is adjusted so that the oxidizing composition is composed of: 70 g of nitric acid, 30 g of hydrogen peroxide, and 20 g of hydrofluoric acid per 100 g of water.

[0118] Example 7

[0119] The method is basically the same as Example 1, except that hydrofluoric acid is replaced by hydrochloric acid.

[0120] Example 8

[0121] It is basically the same as Example 1, except that 14 When irradiating target materials with a temperature of -20°C, use 35°C.

[0122] Example 9

[0123] It is basically the same as Example 1, except that 14 When irradiating the target material with C, 100℃ is used instead of 35℃.

[0124] Comparative Example 1

[0125] Preparation of oxidation composition

[0126] 2 g of potassium iodate, 10 g of chromium trioxide, 66.8 mL of concentrated phosphoric acid solution (mass fraction 85%), and 133.2 mL of concentrated sulfuric acid solution (mass fraction 98%) were mixed to obtain an oxidizing composition.

[0127] Processing 14 C irradiation target

[0128] 50 ml of the above oxidation composition was placed in a reaction bottle, and then 10 g of aluminum nitride target material was slowly added to the reaction bottle at 145° C. The mixed gas generated after oxidation was passed through a quantitative acidic potassium permanganate solution and a sodium hydroxide absorption liquid in sequence. The remaining oxidation solution was subjected to reduced pressure distillation to obtain residual solids after oxidation.

[0129] test

[0130] The test results of the above-mentioned Examples 1-9 and Comparative Example 1 are shown in Table 1 below.

[0131] Table 1

[0132]

[0133] Note: The calculation formula in Table 1 is as follows:

[0134] Nitrogen oxide content = (5 × molar amount of potassium permanganate / molar amount of nitrogen in target material) × 100%;

[0135] The oxidation composition has an effect on the target material 14 C extraction rate = (sodium hydroxide absorption liquid 14 C molar amount / target material 14 C molar amount) × 100%

[0136] It can be clearly seen from Table 1 that the oxidizing composition and the method for treating an irradiated target material containing radioactive substances disclosed in the present invention can effectively improve the oxidation efficiency and reduce the generation of by-product nitrogen oxides, and the oxidized solution can be reduced in volume by a simple direct reduced pressure distillation treatment, which effectively solves the problems of complex post-treatment process, large amount of radioactive waste and high cost existing in the traditional wet process, thereby achieving obvious beneficial technical effects.

[0137] It should be noted that the present disclosure is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and embodiments having substantially the same structure as the technical idea and exerting the same effects within the scope of the technical solution of the present disclosure are all included in the technical scope of the present disclosure. In addition, within the scope of the present disclosure, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present disclosure.

Claims

1. An oxidizing composition comprising: Volatile acids with oxidizing properties; Hydrogen peroxide; optionally a volatile acid having complexing properties; and Solvent.

2. The oxidizing composition according to claim 1, wherein: Based on 100 parts by weight of the solvent, the content of the oxidizing volatile acid is 10-120 parts by weight, preferably 20-100 parts by weight, more preferably 40-80 parts by weight, further preferably 50-70 parts by weight, most preferably 62 parts by weight, and / or Based on 100 parts by weight of the solvent, the content of the hydrogen peroxide is 5-50 parts by weight, preferably 10-40 parts by weight, more preferably 20-30 parts by weight, most preferably 21 parts by weight, and / or Based on 100 parts by weight of the solvent, the content of the complexing volatile acid is 0-30 parts by weight, preferably 5-20 parts by weight, more preferably 10-15 parts by weight, and most preferably 14 parts by weight.

3. The oxidizing composition according to claim 1 or 2, wherein The volatile oxidizing acid is nitric acid; and / or The volatile acid with complexing property is hydrofluoric acid and / or hydrochloric acid; and / or The solvent is an aqueous solvent and / or an ionic liquid, preferably water.

4. A method for preparing an oxidizing composition comprising mixing the following components: Volatile acids with oxidizing properties; Hydrogen peroxide; optionally a volatile acid having complexing properties; and Solvent.

5. The oxidizing composition according to claim 4, wherein: Based on 100 parts by weight of the solvent, the content of the oxidizing volatile acid is 10-120 parts by weight, preferably 20-100 parts by weight, more preferably 40-80 parts by weight, further preferably 50-70 parts by weight, most preferably 62 parts by weight, and / or Based on 100 parts by weight of the solvent, the content of the hydrogen peroxide is 5-50 parts by weight, preferably 10-40 parts by weight, more preferably 20-30 parts by weight, most preferably 21 parts by weight, and / or Based on 100 parts by weight of the solvent, the content of the complexing volatile acid is 0-30 parts by weight, preferably 5-20 parts by weight, more preferably 10-15 parts by weight, and most preferably 14 parts by weight.

6. The oxidizing composition according to claim 4 or 5, wherein The volatile oxidizing acid is nitric acid; and / or The volatile acid with complexing property is hydrofluoric acid and / or hydrochloric acid; and / or The solvent is an aqueous solvent and / or an ionic liquid, preferably water.

7. The oxidizing composition according to any one of claims 1 to 3 or the oxidizing composition prepared by the method according to any one of claims 4 to 6 is used for oxidizing an irradiated target material containing a radioactive substance, preferably containing 14 C irradiated target material and / or irradiated target material containing radioactive material for cracking and filling, preferably containing 14 Use of metal shell of irradiated target material of C.

8. The use according to claim 7, wherein The said 14 The irradiated target material of C is selected from one or more of the following groups: irradiated aluminum nitride, irradiated magnesium nitride, irradiated silicon nitride, irradiated calcium nitride and irradiated beryllium nitride, preferably irradiated aluminum nitride.

9. A method for treating an irradiation target material containing a radioactive substance, comprising: (1) contacting the irradiated target material containing the radioactive substance with the oxidizing composition according to any one of claims 1 to 3 or the oxidizing composition prepared by the method according to any one of claims 4 to 6 to carry out an oxidation reaction to produce a gaseous product containing the radioactive substance; as well as (2) Optionally, the solution obtained after the reaction in step (1) is subjected to solid-liquid separation treatment.

10. The method according to claim 9, wherein: The irradiation target material containing radioactive substances is 14 C irradiation target material, and preferably, the 14 The irradiated target material of C is selected from one or more of the following groups: irradiated aluminum nitride, irradiated magnesium nitride, irradiated silicon nitride, irradiated calcium nitride and irradiated beryllium nitride, preferably irradiated aluminum nitride.

11. The method according to claim 9 or 10, wherein in step (1), the volume / weight ratio of the oxidizing composition to the irradiated target material containing the radioactive substance is 0.5-100 mL / g, preferably 50 mL / g; and / or The step (1) is carried out at a temperature of -30 to 100°C.

12. The method according to claim 9 or 10, wherein the step (1) comprises: The irradiated target material containing radioactive material is added to the oxidizing composition under optional stirring, and preferably, the step (1) is carried out at a temperature of -20 to 100°C, preferably 0 to 80°C, more preferably 20 to 60°C, further preferably 30 to 40°C, and most preferably 35°C.

13. The method according to claim 12, wherein: When the oxidizing composition in step (1) comprises hydrochloric acid, step (1) is performed at a temperature of -20 to 60°C, preferably 0 to 40°C.

14. The method according to claim 9 or 10, wherein the step (1) comprises: The oxidizing composition is added, preferably dropwise, to the irradiated target material containing the radioactive substance, optionally under stirring, and preferably, the step (1) is carried out at a temperature of -30 to 60°C, preferably -20 to 30°C.

15. The method according to claim 14, wherein: When the oxidizing composition in step (1) comprises hydrochloric acid, step (1) is performed at a temperature of -30 to 50°C, preferably -25 to 25°C.

16. The method according to claim 9 or 10, wherein the solid-liquid separation treatment in step (2) is carried out by distillation, preferably reduced pressure distillation.

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