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CN-122016769-A - Method for measuring zirconium content in high-purity hafnium

CN122016769ACN 122016769 ACN122016769 ACN 122016769ACN-122016769-A

Abstract

The application relates to a method for measuring zirconium content in high-purity hafnium, and belongs to the technical field of chemical detection. According to the application, firstly, the zirconium content in a series of hafnium matrix internal control samples is accurately measured by utilizing an inductively coupled plasma emission spectrometry to obtain traceable constant concentration data, so that a solid standard series with known concentration is established for subsequent analysis. Then, using these constant hafnium matrix internal control samples as calibration materials, measuring the signal intensity ratio of zirconium and hafnium in glow discharge mass spectrometry, and constructing a dedicated, matrix-matched calibration curve based on the constant concentration. This curve establishes a deterministic relationship between signal response and true concentration under the instrument conditions. And finally, analyzing the to-be-detected high-purity hafnium sample under the same condition, and substituting the obtained signal intensity ratio into a calibration curve to calculate the accurate zirconium content.

Inventors

  • Cao Hehuan
  • ZHANG XINPING

Assignees

  • 北京北冶新材料股份有限公司

Dates

Publication Date
20260512
Application Date
20260209

Claims (10)

  1. 1. The method for measuring the zirconium content in the high-purity hafnium is characterized by comprising the following steps of: performing inductively coupled plasma emission spectrometry analysis on at least three hafnium substrate internal control samples with zirconium content distributed in a gradient manner to realize accurate fixed values of the zirconium content in the hafnium substrate internal control samples, so as to obtain fixed value zirconium concentration of each hafnium substrate internal control sample; performing solid sample preparation treatment on the hafnium substrate internal control sample with the fixed value and the high-purity hafnium sample to be detected to obtain a sample suitable for glow discharge mass spectrometry; Performing glow discharge mass spectrometry on the hafnium substrate internal control sample under the set instrument parameters to obtain the signal intensity ratio of zirconium to hafnium in the hafnium substrate internal control sample; establishing a calibration curve by taking the constant value zirconium concentration of each hafnium-based internal control sample as an ordinate and the corresponding signal intensity ratio of zirconium to hafnium in the hafnium-based internal control sample as an abscissa; and determining the signal intensity ratio of zirconium to hafnium in the high-purity hafnium sample to be detected, and substituting the signal intensity ratio of zirconium to hafnium in the high-purity hafnium sample to be detected into the calibration curve to obtain the zirconium content in the high-purity hafnium sample to be detected.
  2. 2. The method of claim 1, wherein said inductively coupled plasma emission spectrometry analysis of said at least three hafnium substrate internal control samples having a gradient distribution of zirconium content to achieve accurate determination of zirconium content in said hafnium substrate internal control samples to obtain a constant zirconium concentration for each of said hafnium substrate internal control samples comprises: Carrying out acid dissolution digestion treatment on the hafnium matrix internal control sample to completely convert the solid sample into a solution form, thereby obtaining a sample to-be-measured solution; And carrying out inductively coupled plasma emission spectrometry on the sample to be measured, wherein each hafnium substrate internal control sample is measured in parallel for a plurality of times to obtain a zirconium concentration measurement average value, and the zirconium concentration measurement average value is used as a constant zirconium concentration.
  3. 3. The method of claim 2, wherein the digestion solution used in the acid-soluble digestion treatment is mixed acid of hydrofluoric acid and nitric acid, the mass fraction of the hydrofluoric acid is 48% -50%, the mass fraction of the nitric acid is 70% -72%, and the volume ratio of the hydrofluoric acid to the nitric acid is (2-10): 1-4.
  4. 4. The method according to claim 2, wherein the number of measurements for each of the hafnium-based internal control samples is 3 to 10, and wherein the relative standard deviation of the plurality of measurements is 10% or less.
  5. 5. The method of claim 1, wherein the solid sample preparation process comprises a mechanical forming process, a surface grinding process, an acid washing process, an ultrasonic cleaning process, a drying process, and a pre-sputtering process.
  6. 6. The method according to claim 5, wherein the machining forming process is performed to process the hafnium substrate internal control sample and the high purity hafnium sample to be measured into a cylinder with a diameter of 15mm to 30 mm and a thickness of 10mm to 20 mm.
  7. 7. The method according to claim 5, wherein the solution used in the pickling treatment is an aqueous solution of nitric acid, the volume ratio of nitric acid to water in the aqueous solution of nitric acid is (1-4): 5-10%, and the pickling treatment time is 5 min-15 min.
  8. 8. The method of claim 1, wherein the set instrument parameters include signal acquisition using a resolution mode having a mass resolution of not less than 4000.
  9. 9. The method according to claim 8, wherein the discharge conditions measured by the glow discharge mass spectrometry are a discharge voltage of 800V to 1200V and a discharge current of 1mA to 3 mA under the set instrument parameters.
  10. 10. The method of claim 1, wherein the glow discharge mass spectrometry measurement selects 90 Zr as an analytical isotope of zirconium and 180 Hf as an internal standard isotope of hafnium.

Description

Method for measuring zirconium content in high-purity hafnium Technical Field The application relates to the technical field of chemical detection, in particular to a method for measuring zirconium content in high-purity hafnium. Background Hafnium is an important rare metal, and has irreplaceable functions in the fields of nuclear industry (reactor control rod), aerospace (superalloy), electronic information (semiconductor target material) and the like due to excellent performances such as high melting point (2227 ℃), strong corrosion resistance, large neutron absorption section and the like. The purity of the nuclear-grade high-purity hafnium generally reaches more than 99.99%, and the impurity content directly determines the use safety and performance stability of the material. Zirconium and hafnium belong to the same group of elements, have very similar chemical properties and are highly associated in minerals, so that even through a complicated separation and purification process, trace zirconium impurities are unavoidable in the high-purity hafnium product. However, zirconium has a thermal neutron absorption cross section that is several orders of magnitude lower than hafnium, and the presence of zirconium can significantly impair the neutron absorption efficiency of the material. To ensure the performance of nuclear grade hafnium materials, accurate determination of extremely low zirconium impurity levels therein is necessary. Currently, the determination of the zirconium content in the high-purity hafnium mainly depends on the following two types of technical schemes, but each of the schemes has limitations that an inductively coupled plasma emission spectrometry (ICP-OES) is a common quantitative element analysis means in a laboratory, but for the high-purity hafnium with the purity higher than 99.99%, wherein the zirconium content is close to or lower than the detection limit of a conventional ICP-OES method, the signal to noise ratio of an instrument is deteriorated, the accuracy and the repeatability of a determination result are obviously reduced, and the severe requirement of a nuclear material on trace impurity monitoring is difficult to meet. The Glow Discharge Mass Spectrometry (GDMS) is a direct solid sample injection technology, has the outstanding advantages of extremely high sensitivity (the detection limit can reach ng/g level), relatively small matrix effect, no need of complex chemical pretreatment and the like, and is very suitable for trace impurity analysis of high-purity materials. However, the GDMS method has high sensitivity, but suffers from the difficult problem of calibration and tracing, and the quantitative accuracy is difficult to ensure. Disclosure of Invention The application provides a method for determining the zirconium content in high-purity hafnium, which aims to solve the technical problem of how to accurately, stably and traceably quantitatively determine trace zirconium in a high-purity hafnium substrate. The embodiment of the application provides a method for measuring the zirconium content in high-purity hafnium, which comprises the following steps: performing inductively coupled plasma emission spectrometry analysis on at least three hafnium substrate internal control samples with zirconium content distributed in a gradient manner to realize accurate fixed values of the zirconium content in the hafnium substrate internal control samples, so as to obtain fixed value zirconium concentration of each hafnium substrate internal control sample; performing solid sample preparation treatment on the hafnium substrate internal control sample with the fixed value and the high-purity hafnium sample to be detected to obtain a sample suitable for glow discharge mass spectrometry; Performing glow discharge mass spectrometry on the hafnium substrate internal control sample under the set instrument parameters to obtain the signal intensity ratio of zirconium to hafnium in the hafnium substrate internal control sample; establishing a calibration curve by taking the constant value zirconium concentration of each hafnium-based internal control sample as an ordinate and the corresponding signal intensity ratio of zirconium to hafnium in the hafnium-based internal control sample as an abscissa; and determining the signal intensity ratio of zirconium to hafnium in the high-purity hafnium sample to be detected, and substituting the signal intensity ratio of zirconium to hafnium in the high-purity hafnium sample to be detected into the calibration curve to obtain the zirconium content in the high-purity hafnium sample to be detected. Optionally, the inductively coupled plasma emission spectrometry analysis is performed on the hafnium substrate internal control samples with at least three zirconium contents in gradient distribution, so as to achieve accurate value determination of the zirconium contents in the hafnium substrate internal control samples, and obtain the value-fixed zirc