Uranium radioactive decontaminant and uranium removing method of uranium-containing device
阅读说明：本技术 一种铀放射性去污剂、一种含铀器件的除铀方法 (Uranium radioactive decontaminant and uranium removing method of uranium-containing device ) 是由 仇月双 魏鑫 徐乐昌 于 2021-08-27 设计创作，主要内容包括：本发明提供了一种铀放射性去污剂、一种含铀器件的除铀方法,属于放射性元素处理技术领域。本发明提供的铀放射性去污剂,包括以下质量份的组分：水100份；复合螯合剂0.1～10份；表面活性剂1～10份；所述复合螯合剂为乙二胺四乙酸四钠、乙二胺四乙酸二钠、氮基三乙酸、二乙烯三胺五乙酸、N-羟乙基乙二胺三乙酸和羟基乙叉二膦酸中的两种或两种以上。本发明使用多种螯合剂进行复配使用,能够显著提高去污剂对铀元素的去除率。实施例结果表明,本发明提供的去污剂去污率≥99.8％。(The invention provides a uranium radioactive decontaminating agent and a uranium removing method for a uranium-containing device, and belongs to the technical field of radioactive element treatment. The uranium radioactive detergent provided by the invention comprises the following components in parts by mass: 100 parts of water; 0.1-10 parts of a compound chelating agent; 1-10 parts of a surfactant; the compound chelating agent is two or more than two of ethylene diamine tetraacetic acid tetrasodium, ethylene diamine tetraacetic acid disodium, nitrilotriacetic acid, diethylenetriamine pentaacetic acid, N-hydroxyethyl ethylenediamine triacetic acid and hydroxy ethylidene diphosphonic acid. According to the invention, a plurality of chelating agents are used in a compounding manner, so that the removal rate of uranium element by the decontaminating agent can be obviously improved. The results of the examples show that the decontamination rate of the detergent provided by the invention is more than or equal to 99.8%.)
1. A uranium radioactive detergent comprises the following components in parts by mass:
100 parts of water;
0.1-10 parts of a compound chelating agent;
1-10 parts of a surfactant;
the compound chelating agent is two or more than two of ethylene diamine tetraacetic acid tetrasodium, ethylene diamine tetraacetic acid disodium, nitrilotriacetic acid, diethylenetriamine pentaacetic acid, N-hydroxyethyl ethylenediamine triacetic acid and hydroxy ethylidene diphosphonic acid.
2. A uranium radioactive detergent according to claim 1, comprising the following components in parts by mass:
100 parts of water;
2-6 parts of a compound chelating agent;
4-8 parts of a surfactant.
3. A uranium radioactive detergent according to claim 1 or 2, wherein the complex chelating agent is disodium ethylenediaminetetraacetate and nitrilotriacetic acid.
4. A uranium radioactive detergent according to claim 1 or 2, wherein the complex chelating agent is hydroxyethylidene diphosphonic acid and diethylenetriaminepentaacetic acid.
5. A uranium radioactive detergent according to claim 1 or 2, wherein the complex chelating agent is N-hydroxyethyl ethylenediaminetriacetic acid and disodium ethylenediaminetetraacetate.
6. A uranium radioactive detergent according to claim 1 or 2, wherein the surfactant is one or more of sodium stearate, sodium dodecylbenzenesulfonate, fatty alcohol polyoxyethylene ether, potassium sorbate, oleoyl diethylenetriamine, dodecyl diethanolamide, sorbitol laurate and sorbitan monostearate.
7. A uranium removing method for a uranium-containing device comprises the following steps:
placing a uranium-containing device in a uranium radioactive decontamination agent according to any one of claims 1 to 6, and carrying out ultrasonic cleaning.
8. A uranium removal method according to claim 7, wherein the ultrasonic cleaning frequency is 50-100 Hz and the power is 350-700W.
9. A uranium removal method according to claim 7 or 8, wherein the time of the ultrasonic cleaning is 20-40 min.
Technical Field
The invention relates to the technical field of radioactive element treatment, in particular to a uranium radioactive decontaminating agent and a uranium removing method for a uranium-containing device.
Background
Uranium mining and metallurgy facilities and nuclear power plants generate a large number of radioactive devices in the operation process, and the radioactive devices which are retired must be decontaminated in order to guarantee the environmental radiation safety.
The radioactive device contains radioactive elements, mainly uranium. At present, the methods for removing uranium element in radioactive equipment or parts mainly include a mechanical decontamination method, an electrochemical decontamination method, a biological decontamination method and a chemical decontamination method. The chemical decontamination method is to contact the contaminated material with a proper chemical reagent and achieve the purpose of decontamination through the dissolving effect of the chemical reagent on radioactive contaminants. The chemical decontamination method has the advantages of simple and convenient operation, low cost, repeated use of the decontaminating agent and less harmful waste generated in the decontamination process, and is widely applied.
The main components of the prior uranium radioactive detergent comprise acid, alkali, oxidant, chelating agent and the like, wherein the chelating agent widely used is sodium ethylene diamine tetracetate. However, the decontamination rate of pure sodium ethylene diamine tetracetate is low, and the removal rate of uranium is less than 95%.
Disclosure of Invention
In view of the above, the present invention aims to provide a uranium radioactive decontamination agent and a uranium removing method for a uranium-containing device. The uranium radioactive decontaminant provided by the invention can effectively improve the removal rate of uranium in a uranium-containing device.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides a uranium radioactive detergent which comprises the following components in parts by mass:
100 parts of water;
0.1-10 parts of a compound chelating agent;
1-10 parts of a surfactant;
the compound chelating agent is two or more than two of ethylene diamine tetraacetic acid tetrasodium, ethylene diamine tetraacetic acid disodium, nitrilotriacetic acid, diethylenetriamine pentaacetic acid, N-hydroxyethyl ethylenediamine triacetic acid and hydroxy ethylidene diphosphonic acid.
Preferably, the composition comprises the following components in parts by mass:
100 parts of water;
2-6 parts of a compound chelating agent;
4-8 parts of a surfactant.
Preferably, the complex chelating agent is disodium ethylene diamine tetraacetate and nitrilotriacetic acid.
Preferably, the complex chelating agent is hydroxyethylidene diphosphonic acid and diethylenetriamine pentaacetic acid.
Preferably, the complex chelating agent is N-hydroxyethyl ethylenediamine triacetic acid and ethylene diamine tetraacetic acid disodium.
Preferably, the surfactant is one or more of sodium stearate, sodium dodecyl benzene sulfonate, fatty alcohol-polyoxyethylene ether, potassium sorbate, oleoyl diethylenetriamine, dodecyl diethanolamide, sorbitol laurate and sorbitan monostearate.
The invention provides a uranium removing method of a uranium-containing device, which comprises the following steps:
the uranium-containing devices were placed in the uranium radioactive detergent described above and subjected to ultrasonic cleaning.
Preferably, the frequency of the ultrasonic cleaning is 50-100 Hz, and the power is 350-700W.
Preferably, the ultrasonic cleaning time is 20-40 min.
The invention provides a uranium radioactive detergent which comprises the following components in parts by mass: 100 parts of water; 0.1-10 parts of a compound chelating agent; 1-10 parts of a surfactant; the compound chelating agent is two or more than two of ethylene diamine tetraacetic acid tetrasodium, ethylene diamine tetraacetic acid disodium, nitrilotriacetic acid, diethylenetriamine pentaacetic acid, N-hydroxyethyl ethylenediamine triacetic acid and hydroxy ethylidene diphosphonic acid. According to the invention, a plurality of chelating agents are used in a compounding manner, so that the removal rate of uranium element by the decontaminating agent can be obviously improved, and a complex with a more stable structure can be formed with uranyl ions due to the existence of two or more chelating agents with different structures in the solution, thereby being beneficial to removing uranium. The results of the examples show that the decontamination rate of the detergent provided by the invention is more than or equal to 99.8%.
The invention provides a uranium removing method of a uranium-containing device, which comprises the following steps: the uranium-containing devices were placed in the uranium radioactive detergent described above and subjected to ultrasonic cleaning. The method adopts a mode of combining uranium radioactive decontaminant and ultrasonic waves, and can effectively remove uranium elements in uranium-containing devices. Meanwhile, the method provided by the invention is simple to operate, low in cost and suitable for industrial popularization and application.
Detailed Description
The invention provides a uranium radioactive detergent which comprises the following components in parts by mass:
100 parts of water;
0.1-10 parts of a compound chelating agent;
1-10 parts of a surfactant;
unless otherwise specified, the starting materials used in the present invention are commercially available.
The compound chelating agent is two or more than two of ethylene diamine tetraacetic acid tetrasodium, ethylene diamine tetraacetic acid disodium, nitrilotriacetic acid, diethylenetriamine pentaacetic acid, N-hydroxyethyl ethylenediamine triacetic acid and hydroxy ethylidene diphosphonic acid.
The uranium radioactive detergent provided by the invention comprises 100 parts of water by mass. In the present invention, the water is preferably deionized water.
Based on the mass part of the water, the uranium radioactive detergent provided by the invention comprises 0.1-10 parts of a composite chelating agent, preferably 2-6 parts, and more preferably 4-5 parts. In the invention, the compound chelating agent is two or more than two of ethylene diamine tetraacetic acid tetrasodium, ethylene diamine tetraacetic acid disodium, nitrilotriacetic acid, diethylenetriamine pentaacetic acid, N-hydroxyethyl ethylenediamine triacetic acid and hydroxyethylidene diphosphonic acid. In the invention, when the two composite chelating agents are used, the mass ratio of the two chelating agents is preferably 1-10: 1-10, and more preferably 3-5: 3-5; when the number of the complex chelating agents is more than two, the mass ratio of any component to the rest of the components in the complex chelating agents is preferably 1-10: 1-10, and more preferably 3-5: 3-5.
In the invention, the compound chelating agent is preferably disodium ethylene diamine tetraacetate and nitrilotriacetic acid; in the invention, the mass ratio of the ethylene diamine tetraacetic acid disodium to the nitrilotriacetic acid is preferably 2: 1.
In the invention, the complex chelating agent is preferably hydroxyethylidene diphosphonic acid and diethylenetriaminepentaacetic acid; the mass ratio of the hydroxyethylidene diphosphonic acid to the diethylenetriamine pentaacetic acid is preferably 1: 2.
In the invention, the compound chelating agent is preferably N-hydroxyethyl ethylenediamine triacetic acid and ethylene diamine tetraacetic acid disodium; in the present invention, the mass ratio of N-hydroxyethyl ethylenediaminetriacetic acid to disodium ethylenediaminetetraacetate is preferably 1: 1.
Based on the mass part of the water, the uranium radioactive decontaminating agent provided by the invention comprises 1-10 parts of surfactant, preferably 4-8 parts, and more preferably 5-6 parts. In the invention, the surfactant is preferably one or more of sodium stearate, sodium dodecyl benzene sulfonate, fatty alcohol-polyoxyethylene ether, potassium sorbate, oleoyl diethylenetriamine, dodecyl diethanolamide, sorbitol laurate and sorbitan monostearate.
In the invention, the preparation method of the uranium radioactive detergent comprises the following steps:
and mixing water, a composite chelating agent and a surfactant to obtain the uranium radioactive detergent.
The mixing mode of the invention has no special requirement, and the components are uniformly mixed by using a mode of the technology in the field, such as stirring and mixing. In the present invention, the temperature of the mixing is preferably room temperature.
The invention provides a uranium removing method of a uranium-containing device, which comprises the following steps:
the uranium-containing devices were placed in the uranium radioactive detergent described above and subjected to ultrasonic cleaning.
In the present invention, the material of the uranium-containing device is preferably metal, plastic, glass or ceramic, and as a specific embodiment of the present invention, the material of the uranium-containing device is stainless steel.
The method has no special requirement on the dosage of the uranium radioactive decontaminant, and can completely immerse the uranium-containing device.
In the invention, the frequency of ultrasonic cleaning is preferably 50-100 Hz, and more preferably 60-80 Hz; the power is preferably 350 to 700W, more preferably 500 to 600W.
In the invention, the ultrasonic cleaning time is preferably 20-40 min, and more preferably 20-30 min.
The following provides a detailed description of a uranium radioactive decontamination agent and a uranium removal method for a uranium-containing device according to the present invention with reference to the following examples, which should not be construed as limiting the scope of the present invention.
Example 1
0.2g of disodium ethylene diamine tetraacetate and 0.1g of nitrilotriacetic acid are added into a 500mL three-necked flask with a stirring paddle and a thermometer, then 100mL of deionized water is added, and stirring is carried out at room temperature until the chelating agent is completely dissolved. Then, 2g of sodium dodecylbenzenesulfonate was added and stirred to dissolve it completely, thereby obtaining a uranium radioactive detergent.
The uranium removing effect of the obtained uranium radioactive detergent is tested by the following method:
cleaning a stainless steel sheet with the thickness of 80 multiplied by 2mm by using a detergent powder, drying, then soaking in 5% HCl for 4 hours, drying at 50 ℃, and measuring the surface pollution background value for later use. And soaking the prepared stainless steel sheet in 5g/L uranium solution for 5-10 min, draining, drying at 50 ℃, repeating the operation for 6 times, and determining the surface pollution of the polluted stainless steel sheet. Uniformly coating the synthesized polyvinyl alcohol detergent on a contaminated steel sheet, placing the steel sheet in a room temperature environment, drying, stripping the film, measuring the surface contamination level of the decontaminated steel sheet, measuring 5 points of each sample, and calculating the decontamination rate according to the following formula to obtain the decontamination effect of different stripping film detergents.
DE is detergency,%;
a1 is the surface pollution value of the polluted sample without background subtraction, Bq/cm2；
A2 is unbuckledBackground-removing decontamination sample surface contamination value, Bq/cm2；
A0 is background value before sample contamination, Bq/cm2；
The steel sheet background value is 0.261Bq/cm2The content of the contaminated steel sheet in the uranium solution is 0.603Bq/cm2The surface pollution of the steel sheet after decontamination is 0.256Bq/cm2The decontamination rate is 99.8%.
Example 3
0.3g of N-hydroxyethyl ethylenediamine triacetic acid, 0.3g of ethylene diamine tetraacetic acid and 100mL of deionized water are added into a 500mL three-necked flask with a stirring paddle and a thermometer, and the mixture is stirred at room temperature until the chelating agent is completely dissolved. Then, 2g of sorbitan monostearate was added thereto and the resulting mixture was stirred to dissolve the sorbitan monostearate, thereby obtaining a uranium radioactive detergent. The detergency ratio was measured according to the method of example 1, and as a result, it was 99.9%.
Examples 2 to 10
In the embodiments 2 to 10, the preparation methods of the uranium radioactive detergents are the same, and the differences are that the raw material components and the dosages are different, and the raw material components and the dosages of the embodiments 2 to 10 are shown in table 1.
Comparative examples 1 to 6
The raw material components and the amounts used in comparative examples 1 to 6 are shown in Table 1.
TABLE 1 raw material Components and amounts of examples 2 to 10 and comparative examples 1 to 6
Example 11
The surface of uranium is polluted to be 1.06Bq/cm2The uranium-containing device obtained in example 1 was placed in the radioactive uranium decontaminant, and ultrasonic cleaning was carried out at a power of 350W, a frequency of 50Hz, and a time of 20 min. The uranium content of the cleaned uranium-containing device is detected, and the result shows that the surface contamination is 0.23Bq/cm2。
Example 12
The uranium content is 0.92Bq/cm2The uranium-containing device obtained in example 2 was placed in the radioactive uranium detergent for ultrasonic cleaning at a power of 700W and a frequency of 100Hz for 30 min. The uranium content of the cleaned uranium-containing device is detected, and the result shows that the surface contamination is 0.25Bq/cm2。
Example 13
The uranium content is 0.76Bq/cm2The uranium-containing device obtained in example 3 was placed in the radioactive uranium detergent and subjected to ultrasonic cleaning at a power of 600W, a frequency of 100Hz and a time of 40 min. The uranium content of the cleaned uranium-containing device is detected, and the result shows that the surface contamination is 0.22Bq/cm2。
Comparative example 7
Compared with example 11, no ultrasound was performed, and a general cleaning manner was employed. The uranium content of the cleaned uranium-containing device is detected, and the result shows that the surface contamination is 0.56Bq/cm2。
Comparative example 8
Compared with example 12, no ultrasound was performed, and a general cleaning method was used. The uranium content of the cleaned uranium-containing device is detected, and the result shows that the surface contamination is 0.43Bq/cm2。
Comparative example 9
In contrast to example 13, no sonication was performed and the normal washing was used. The uranium content of the cleaned uranium-containing device is detected, and the result shows that the surface contamination is 0.61Bq/cm2。
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.