Analysis method for rapidly determining moisture content in uranium trioxide

Abstract

The invention discloses an analysis method for rapidly measuring the water content in uranium trioxide. The analysis method comprises the following steps: S1, correcting a blank value; s2, instrument correction; s3, sample determination; s4, calculating a result; according to the method, the oxygen-nitrogen-hydrogen analyzer is used for rapidly measuring the moisture in the uranium trioxide powder; no organic reagent is used in the sample measurement process, so that no organic waste liquid is generated.

Description

Technical Field

[0001] The invention relates to the technical field of water content analysis, and specifically to an analytical method for rapidly determining the water content in uranium trioxide. Background Art

[0002] In the field of nuclear analysis, the commonly used method for water determination is the Karl Fischer method, which can be divided into the volumetric method and the coulometric method. The volumetric method consumes a large amount of reagents and has low measurement accuracy. The coulometric method is a method in which the water meter injects the sample under the premise of the electrolytic cell being balanced, which has the advantages of high accuracy and rapid measurement.

[0003] The determination of moisture content in uranium trioxide powder usually adopts the industry standard "EJ / T 20168-2018 Karl Fischer Coulometry for Determination of Moisture Content in Post-processed Uranium Trioxide Powder", with a determination range of 0.0025% to 1.0%. At present, oxygen, nitrogen and hydrogen analyzers are increasingly used to determine the content of oxygen, nitrogen and hydrogen in steel, alloys and ceramic inorganic materials. They are equipped with multi-bit microprocessors and dual-range thermal conductivity detection cells. The analysis process can achieve switching from low range to high range, and has the advantages of high sensitivity, wide measurement range and fast speed. The analysis range of hydrogen: 0.00001-0.025%, minimum reading: 0.00001%, analysis time: ≤200s.

[0004] Metallic nickel and tin are more active than hydrogen and can reduce hydrogen from their oxides. By measuring the hydrogen content, the water content can be calculated. After uranium trioxide powder is calcined at 450°C, the sample does not contain free hydrogen and organic matter, but the sample will absorb moisture during storage and transportation, changing the moisture content in the sample. The oxygen, nitrogen and hydrogen analyzer is used to determine the total amount of hydrogen in uranium trioxide, convert it into moisture content, and achieve rapid and accurate determination of moisture in uranium trioxide, while enriching the method of determining moisture in uranium trioxide. Summary of the invention

[0005] The purpose of the present invention is to establish an analytical technology for rapidly determining the moisture content in uranium trioxide, and to provide a reference for enriching the moisture determination method of uranium trioxide by using an oxygen, nitrogen and hydrogen analyzer to determine the moisture in the sample.

[0006] The technical solution of the present invention is as follows: an analytical method for rapidly determining the moisture content in uranium trioxide, comprising the following steps:

[0007] S1: blank value correction;

[0008] Degassing the graphite crucible; placing a tin foil in the nickel capsule and then placing it in the graphite crucible; measuring the hydrogen content of the graphite crucible containing the nickel capsule by an oxygen, nitrogen and hydrogen analyzer, and taking the measured value as a blank value;

[0009] S2: Instrument calibration

[0010] Weigh the hydrogen content standard steel sample and obtain its hydrogen content x by its mass 标 ; Put the hydrogen content standard steel sample and tin foil into the nickel capsule and then put it into the graphite crucible to measure the hydrogen content x 测 , instrument calibration is performed through both;

[0011] S3: Sample determination

[0012] After placing uranium trioxide powder and tin foil in a nickel capsule, place it in a graphite crucible for measurement; after deducting the blank value, calculate the hydrogen content in the uranium trioxide powder;

[0013] S4 result calculation

[0014] The moisture content in uranium trioxide powder is expressed as mass fraction ω, and the value is expressed in micrograms per gram, calculated according to the formula:

[0015] ω=18(ω x1 -ω x2 )

[0016] Where:

[0017] ω x1 ——The mass fraction of hydrogen in the sample, in micrograms per gram;

[0018] ω x2 ——Mass fraction of hydrogen in the blank, in micrograms per gram.

[0019] In S1, the graphite crucible is placed on the crucible seat of the oxygen, nitrogen and hydrogen analyzer for degassing; and the nickel capsule is flattened with a nickel capsule clamp.

[0020] In S1, the measurement was performed three times in parallel, and the average value of the three measurements was used as the blank value for correction.

[0021] In S2, if |x 测 -x 标 ∣ / x 标 ≤0.14, the instrument calibration is complete. If |x 测 -x 标 ∣ / x 标 >0.14, then recalibrate, where x 测 is the measured mass fraction of hydrogen, x 标 is the mass fraction of hydrogen in the hydrogen content standard steel sample.

[0022] In S2, the measurement was performed three times in parallel, and the average value of the three measurements was taken as the measured value.

[0023] In S2, standard steel samples with different hydrogen contents are used for verification.

[0024] In S3, the sample test power is set to 5500W.

[0025] In the above S1, degassing was performed twice.

[0026] In S2, the graphite crucible is subjected to a degassing treatment.

[0027] In S3, the graphite crucible is subjected to a degassing treatment.

[0028] The remarkable effects of the present invention are: using an oxygen, nitrogen and hydrogen analyzer to realize rapid measurement of water content in uranium trioxide powder; and no organic reagent is used in the sample measurement process, thereby no organic waste liquid is generated. DETAILED DESCRIPTION

[0029] Many specific details are described in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present application, so the present application is not limited by the specific implementation disclosed below.

[0030] The terms used in one or more embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit one or more embodiments of the present application. The singular forms of "a", "said" and "the" used in one or more embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in one or more embodiments of the present application refers to and includes any or all possible combinations of one or more associated listed items.

[0031] It should be understood that, although the terms first, second, etc. may be used to describe various information in one or more embodiments of the present application, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of one or more embodiments of the present application, the first may also be referred to as the second, and similarly, the second may also be referred to as the first.

[0032] An analytical method for rapidly determining the moisture content in uranium trioxide comprises the following steps:

[0033] S1: Blank value correction

[0034] Place the graphite crucible on the crucible stand of the oxygen, nitrogen and hydrogen analyzer for degassing; put a tin foil in the nickel capsule, cover the nickel capsule with a lid, and then flatten it with a nickel capsule pliers. Put the flattened nickel capsule into the injector and drop it into the graphite crucible. Use the oxygen, nitrogen and hydrogen analyzer to measure the hydrogen content of the graphite crucible with the nickel capsule. Perform three parallel measurements and use the average of the three measurements as the blank value for correction.

[0035] S2: Instrument calibration

[0036] Place the graphite crucible on the crucible stand of the oxygen, nitrogen and hydrogen analyzer for degassing; weigh the hydrogen content standard steel sample and input the mass into the measurement software of the oxygen, nitrogen and hydrogen analyzer; put the hydrogen content standard steel sample and tin foil into the nickel capsule, cover the nickel capsule with the nickel capsule cover, and then flatten it with the nickel capsule clamp; put the flattened nickel capsule into the injector and drop it into the graphite crucible for measurement. Parallel measurement three times, and the average value of the three measurements is taken as the measurement value x 测 If ∣x 测 -x 标 ∣ / x 标 ≤2.8RSD=0.14, then the instrument calibration is complete. If |x 测 -x 标 ∣ / x 标 >2.8RSD=0.14, then re-calibrate.

[0037] The blank value is taken as the blank zero point; standard steel samples with different hydrogen contents are used for verification.

[0038] S3: Sample determination

[0039] Place the graphite crucible on the crucible stand of the oxygen, nitrogen and hydrogen analyzer for degassing; weigh 0.15g of uranium trioxide powder in the nickel capsule, put in tin foil and cover the nickel capsule with a nickel capsule pliers; use the nickel capsule pliers to flatten the nickel capsule and place it in the sampler of the oxygen, nitrogen and hydrogen analyzer and then drop it into the graphite crucible, set the sample power for measurement. After deducting the blank value, the instrument automatically uses the calibrated coefficient to calculate the hydrogen content in the uranium trioxide powder.

[0040] S4 result calculation

[0041] The moisture content in uranium trioxide powder is expressed as mass fraction ω, and the value is expressed in micrograms per gram (μg / g), calculated according to the formula:

[0042] ω=18(ω x1 -ω x2 )

[0043] Where:

[0044] ω x1 ——Mass fraction of hydrogen in the sample, in micrograms per gram (μg / g);

[0045] ω x2 ——Mass fraction of hydrogen in the blank, in micrograms per gram (μg / g).

[0046] In S1.1, the degassing power of the graphite crucible is 6000W, and the degassing times are 2 times;

[0047] In S3.3, the sample test power is set to 5500W.

[0048] The above description is only a preferred embodiment of this patent and is not intended to limit this patent. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this patent should be included in the scope of protection of this patent.

[0049] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described action sequence, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0050] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0051] The preferred embodiments of the present application disclosed above are only used to help explain the present application. The optional embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of the present application. The present application selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can understand and use the present application well.

Claims

1. An analytical method for rapidly determining the moisture content in uranium trioxide, characterized in that: The following steps are involved: S1: blank value correction; Degassing the graphite crucible; placing a tin foil in the nickel capsule and then placing it in the graphite crucible; measuring the hydrogen content of the graphite crucible containing the nickel capsule by an oxygen, nitrogen and hydrogen analyzer, and taking the measured value as a blank value; S2: Instrument calibration Weigh the hydrogen content standard steel sample and obtain its hydrogen content x by its mass 标 ; Put the hydrogen content standard steel sample and tin foil into the nickel capsule and then put it into the graphite crucible to measure the hydrogen content x 测 , instrument calibration is performed through both; S3: Sample determination After placing uranium trioxide powder and tin foil in a nickel capsule, place it in a graphite crucible for measurement; after deducting the blank value, calculate the hydrogen content in the uranium trioxide powder; S4 result calculation The moisture content in uranium trioxide powder is expressed as mass fraction ω, and the value is expressed in micrograms per gram, calculated according to the formula: ω=18(ω x1 -oh x2 ) Where: ω x1 ——The mass fraction of hydrogen in the sample, in micrograms per gram; ω x2 ——Mass fraction of hydrogen in the blank, in micrograms per gram.

2. The method for rapidly determining the moisture content in uranium trioxide according to claim 1, characterized in that: In S1, the graphite crucible is placed on the crucible seat of the oxygen, nitrogen and hydrogen analyzer for degassing; and the nickel capsule is flattened with a nickel capsule clamp.

3. The method for rapidly determining the moisture content in uranium trioxide according to claim 1, characterized in that: In S1, the measurement was performed three times in parallel, and the average value of the three measurements was used as the blank value for correction.

4. The method for rapidly determining the moisture content in uranium trioxide according to claim 1, characterized in that: In S2, if |x 测 -x 标 ∣ / x 标 ≤0.14, the instrument calibration is complete. If |x 测 -x 标 ∣ / x 标 >0.14, then recalibrate, where x 测 is the measured mass fraction of hydrogen, x 标 is the mass fraction of hydrogen in the hydrogen content standard steel sample.

5. The method for rapidly determining the moisture content in uranium trioxide according to claim 4, characterized in that: In S2, the measurement was performed three times in parallel, and the average value of the three measurements was taken as the measured value.

6. The method for rapidly determining the moisture content in uranium trioxide according to claim 1, characterized in that: In S2, standard steel samples with different hydrogen contents are used for verification.

7. The method for rapidly determining the moisture content in uranium trioxide according to claim 1, characterized in that: In S3, the sample test power is set to 5500W.

8. The method for rapidly determining the moisture content in uranium trioxide according to claim 1, characterized in that: In the above S1, degassing was performed twice.

9. The method for rapidly determining the moisture content in uranium trioxide according to claim 1, characterized in that: In S2, the graphite crucible is subjected to a degassing treatment.

10. The method for rapidly determining the water content in uranium trioxide according to claim 1, characterized in that: In S3, the graphite crucible is subjected to a degassing treatment.