Method for detecting hafnium content in zirconium raffinate
By establishing a standard curve for matrix matching and concentration normalization in zirconium raffinate, the interference of zirconium matrix effect was eliminated, and the hafnium content in zirconium raffinate was accurately determined. This solved the problem of large deviation in detection results in the existing technology and improved the accuracy and sensitivity of the detection.
Patent Information
- Application Number
- CN202511104765.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-07
- Publication Date
- 2025-11-07
AI Technical Summary
Existing technologies are easily affected by the zirconium matrix when detecting hafnium content in zirconium leaching residue, resulting in large deviations in the detection results and making it difficult to meet the rapid and accurate requirements of industrial production.
By determining the zirconium content in the zirconium raffinate, a standard point solution with known zirconium content was prepared. Combined with inductively coupled plasma atomic emission spectrometry, a strict matrix matching and concentration normalization standard curve was established to eliminate zirconium matrix effect interference. The zirconium content was determined by EDTA titration and the sample was diluted to be consistent with the standard point solution. ICP-OES was then used for detection.
It significantly improves the accuracy and reliability of detection results, reduces the risk of interference from coexisting elements, and enhances detection sensitivity and precision, meeting the rapid and accurate detection needs of industrial production.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of chemical element content analysis, and particularly relates to a hafnium content detection method in zirconium raffinate. BACKGROUND
[0002] In the industrial production process of zirconium oxide materials, zirconium raffinate is one of the key intermediate process samples, and the composition and content change thereof directly reflects the process stability of the extraction separation link. The solution is mainly generated through mixed extraction reaction of zirconium oxychloride solution, hydrochloric acid, methyl isobutyl ketone (MIBK), ammonium thiocyanate and other reagents, wherein not only the zirconium element not completely separated is remained, but also the target monitoring component hafnium and various extraction agent degradation products and inorganic ions are contained. The zirconium raffinate is precipitated by reacting with ammonium sulfate and ammonia water to obtain zirconium filter cake, and the zirconium oxide product is obtained by high temperature calcination. In the purity index of the zirconium oxide product, the hafnium content is a core control parameter, especially in the high-end application fields such as aerospace and electronic information, the limit requirement of hafnium in zirconium oxide is extremely strict, therefore, the accurate detection of hafnium content in zirconium raffinate has important practical significance for guaranteeing the quality of the final product and optimizing the production process.
[0003] At present, for the detection of trace hafnium elements in the solution, inductively coupled plasma optical emission spectrometry (ICP-OES) has become a common technical means in the industrial detection field due to its wide detection range, high sensitivity, strong multi-element simultaneous analysis ability and other advantages. In the actual detection process, the external standard method commonly used by the conventional method is to prepare a series of hafnium standard solutions with known concentration, draw a standard curve, and then quantitatively analyze the sample solution. For relatively simple samples, this method can meet the basic detection requirements, but when facing the zirconium raffinate system with high matrix complexity, the detection accuracy is greatly challenged. In addition, part of the detection scheme attempts to eliminate interference by matrix matching method, that is, by measuring the actual concentration of zirconium in the sample, a standard solution with similar matrix concentration to the sample is prepared for calibration, and then combined with the spectral method to complete the hafnium content test.
[0004] However, the existing detection method has significant defects and deficiencies when applied to the detection of hafnium content in zirconium raffinate. On the one hand, the zirconium content in zirconium raffinate is extremely high. During the ICP-OES test process, high concentration of zirconium will produce strong matrix interference effect, which is specifically manifested as change of plasma energy distribution, spectral line overlap, ionization competition, etc. The signal intensity of hafnium element characteristic spectrum is inhibited or enhanced, so that the conventional external standard method cannot effectively eliminate such interference, directly causing large deviation of hafnium content detection result, which is difficult to reflect the true value. On the other hand, the matrix matching method has great difficulty in actual operation. Since the concentration of zirconium in zirconium raffinate fluctuates greatly and is significantly affected by extraction process parameters, it is necessary to accurately determine the zirconium content of each sample and then separately configure the matching standard solution, which not only increases the complexity of the detection steps, prolongs the analysis cycle, but also may further amplify the detection deviation of hafnium content due to the determination error of zirconium concentration, which cannot meet the rapid and accurate detection requirements in industrial production. SUMMARY
[0005] The present application aims to provide a method for detecting the content of hafnium in zirconium raffinate, in order to solve the technical problem that the existing technology for detecting the content of hafnium in zirconium raffinate is easily interfered with, resulting in a large deviation in the detection result.
[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solution: a method for detecting the content of hafnium in zirconium raffinate, comprising the following steps: (I) Determining the content of zirconium in zirconium raffinate: S1, dispersing the zirconium raffinate sample in dilute hydrochloric acid, and determining the content of zirconium dioxide in the sample solution by EDTA titration method; (II) Obtaining a standard curve: S2, configuring a standard point solution with a zirconium content of c: selecting a zirconium matrix with a known hafnium content, washing with acid and water, dissolving with acid and constant volume as zirconium matrix stock solution; combining the zirconium matrix stock solution with the purchased hafnium standard solution to configure several standard point solutions; S3, detecting and fitting the standard curve: detecting the above standard point solution in an inductively coupled plasma spectrometer, and fitting the intensity determined by the instrument with the preset hafnium concentration in the standard point solution to obtain a standard curve; (III) Determining the content of hafnium in zirconium raffinate: S4, diluting the zirconium raffinate: diluting the zirconium raffinate sample so that its zirconium content and acid concentration are consistent with those of the standard point solution in S2; S5, referring to the method in S3, detecting the diluted zirconium raffinate in S4, and bringing in the standard curve in S3 to obtain the content of hafnium in the diluted zirconium raffinate.
[0007] The principle and advantages of the present application are as follows: The scheme can maximize the elimination of the interference of zirconium matrix effect on the determination of hafnium content, thereby significantly improving the accuracy and reliability of the detection results. This is the key to solving the problem of trace hafnium analysis in zirconium hafnium separation (especially in raffinate). Specifically, S1 provides key data for S4, S2 / S3 establishes a "scale", S4 processes the sample into a state matching the "scale", and S5 applies the "scale" reading. The design is rigorous, and the accuracy of the detection results is improved. S1 determines the zirconium content in the zirconium raffinate to provide key data for subsequent accurate dilution, so that the zirconium raffinate sample dilution process can achieve consistent zirconium content with the standard point solution, realizing accurate matrix matching and concentration normalization. In the process of configuring the zirconium content c standard point solution, the scheme is different from the ordinary standard curve method, and the zirconium matrix with known hafnium content is used to facilitate accurate assignment of hafnium content during fitting, thereby effectively improving the accuracy of the detection results. When configuring the zirconium matrix stock solution, through continuous acid washing and water washing treatment, the impurity hafnium or other pollutants that may be adsorbed on the surface of the zirconium matrix are effectively removed, ensuring that the "hafnium background" of the matrix is clear, controllable and known, improving the purity and representativeness of the matrix, and making the "known hafnium content" more accurate and reliable. Subsequently, the acid solution is dissolved and diluted to effectively ensure the uniformity and stability of the matrix solution, and the type of dissolving acid should match the subsequent sample treatment and ICP-OES test medium. S3 of the scheme determines the signal intensity (intensity) of different hafnium concentrations under the matched zirconium matrix background, and then fits the standard curve of the intensity and the known hafnium concentration. The curve is the instrument response characteristic of hafnium and the matrix effect under the condition of a specific zirconium concentration (c) and a specific matrix composition, which facilitates the provision of a "scale" for subsequent accurate determination of hafnium content in the sample. In S4, by configuring the zirconium content and acid concentration consistent with the standard point solution, the interference of the matrix effect on the determination of hafnium content is maximized, realizing the accurate determination of hafnium content in the zirconium raffinate.
[0008] In summary, the scheme maximizes the elimination of the interference of zirconium matrix effect on the determination of trace hafnium through double protection (matrix matched standard curve + sample / standard zirconium concentration and acidity normalization), which is a precision that conventional external standard method or simple internal standard method cannot achieve. Again, ICP-OES (inductively coupled plasma optical spectrometer) has good element selectivity, is targeted, and is designed for zirconium raffinate (high zirconium, trace hafnium, and specific matrix), solving the core difficulty (matrix effect) of such sample analysis, further reducing the risk of coexisting element interference, and also improving the detection sensitivity and precision.
[0009] Preferably, as an improvement, in S4, spectral line selection is also included before sample detection, including the following contents: The purchased hafnium standard solution is determined by the instrument, and according to the instrument determination results, the hafnium element spectral line is selected according to the principles of high signal-to-noise ratio, moderate sensitivity, and small matrix interference.
[0010] Preferably, as an improvement, in S3, the zirconium matrix includes any one of a metal zirconium matrix, a zirconium compound matrix, and a zirconium alloy matrix. Preferably, the zirconium matrix is selected from zirconium related products produced when obtaining zirconium raffinate. As its content is basically the same as that of the zirconium raffinate, it can further reduce the interference of other matrices in the zirconium raffinate on the hafnium content detection.
[0011] Preferably, as an improvement, in S3, the hafnium content in the standard point solution is 0 ppm, 1 ppm, 2 ppm, and 5 ppm, respectively. Through an inductively coupled plasma emission spectrometer, a suitable spectral line wavelength is selected, and the hafnium content in the zirconium raffinate is accurately quantitatively analyzed by using the linear relationship between the concentration and the intensity.
[0012] Preferably, as an improvement, in S3, the hafnium element source in the standard point solution includes a hafnium standard solution and a zirconium matrix stock solution. Fully considering the hafnium element in the zirconium standard stock solution, the detection result is closer to the actual value, and the accuracy is higher.
[0013] Preferably, as an improvement, in S1 and S2, the dilute hydrochloric acid solution has a concentration of 3.7%. The dilute hydrochloric acid solution is obtained by diluting 37% concentrated hydrochloric acid with pure water at a volume ratio of 1:9. The inventors have found through long-term experiments that the acidity of the dilute hydrochloric acid solution is suitable for realizing complete ion replacement in the complexation reaction. If the acidity is too low, the replacement will not be complete, and the color change during titration will be too shallow, thereby reducing the detection accuracy.
[0014] Preferably, as an improvement, in S3, the pickling treatment is to use a digestion solution to pickle the zirconium matrix at room temperature 20-27℃ for 1-2 min, and the digestion solution is composed of 70% nitric acid, 49% hydrofluoric acid, and pure water at a volume ratio of 34-38:7-9:33-39. The digestion solution mainly dissolves and removes the surface oxides and impurities of the zirconium matrix to achieve the effect of surface cleaning. The inventors have found through long-term experiments that if the content of hydrofluoric acid is too high, the elution amount of the zirconium matrix will be too large, causing waste. If the content of hydrofluoric acid is too low, on the one hand, it takes a longer time to remove the surface oxides and impurities, reducing the detection efficiency; on the other hand, the reaction will not be intense enough, and the zirconium may not be dissolved, failing to achieve the effect of surface cleaning.
[0015] Preferably, as an improvement, in S3, the acid solution is composed of 70% nitric acid, 49% hydrofluoric acid, and pure water at a volume ratio of 100:295-305:395-405. The acid solution effectively ensures the complete dissolution of the zirconium matrix, facilitating the preparation of the standard point solution.
[0016] Preferably, as an improvement, the deviation between the zirconium content c in the zirconium raffinate sample and the zirconium content c in the standard solution is less than or equal to 1%; the zirconium content c is 2~10 g / L. By comparing the different intensity values of hafnium measured on an inductively coupled plasma spectrometer with different zirconium concentrations, it can be determined that zirconium matrix matching is necessary to ensure the uniformity of zirconium matrix concentration in the sample and standard solution, thereby improving the accuracy of detection.
[0017] Preferably, as an improvement, the detection limit of the method is determined by performing non-continuous testing on blank samples for three days, wherein the detection limit is 3 ppm and the detection range is 3~500 ppm.
[0018] The principle and advantages of this scheme are: 1. This method utilizes EDTA standard solution (disodium ethylenediaminetetraacetate) to test the zirconium concentration in the zirconium raffinate. The zirconium content concentration in the raffinate can then be calculated and converted to a concentration equivalent to the standard solution. This facilitates diluting the zirconium raffinate sample to match the zirconium content (c) in the standard solution, effectively eliminating interference from the zirconium matrix in different sample solutions during testing. Compared to conventional dilution methods, this method provides more accurate results.
[0019] 2. This method uses four new standard curve points: 0 ppm, 1 ppm, 2 ppm, and 5 ppm. When editing the hafnium content data for these four standard points, the hafnium concentration in the zirconium matrix needs to be added. The range of the tested samples must be within the range from the blank point to the highest point of the curve (i.e., 500 ppm before 100-fold dilution) for the test results to be valid. Compared to conventional standard points that do not include the hafnium impurity content in the zirconium matrix, the test results obtained using this method are more accurate and effective.
[0020] 3. This method reduces the interference of zirconium in the sample on the hafnium matrix by adding high-purity zirconium matrix to the standard solution and comparing the zirconium concentration in the standard solution with the zirconium content in the sample. This method is more accurate and effective than the conventional external standard method. Attached Figure Description
[0021] Figure 1 This is a four-point fitted linear graph in Embodiment 1 of the present invention.
[0022] Figure 2 This is a diagram showing the results of 21 discontinuous verification sample inspections in Embodiment 1 of the present invention. Detailed Implementation
[0023] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto. Unless otherwise specified, the technical means used in the following embodiments and experimental examples are conventional means well known to those skilled in the art, and the materials, reagents, etc. used can all be obtained commercially.
[0024] Example 1 The present scheme provides a method for detecting hafnium content in zirconium raffinate, comprising the following steps: (I) Determining the zirconium content in the zirconium raffinate: S1, detecting the zirconium content in the zirconium raffinate, comprising the following steps: S1-1, add 50ml dilute hydrochloric acid (1+9, i.e. the dilute hydrochloric acid solution is 37% concentrated hydrochloric acid diluted with pure water in a volume ratio of 1:9) to a clean 250ml conical flask.
[0025] S1-2, accurately pipette 1ml of the zirconium raffinate sample to be tested into the above conical flask, shake well to obtain the sample solution.
[0026] S1-3, place the conical flask on an electric stove and heat to boiling.
[0027] S1-4, add 3 drops of dimethyl phenol orange indicator and shake well.
[0028] S1-5, titrate the sample solution with EDTA titration solution from magenta to light yellow to no discoloration as the end point. Repeat heating 2-3 times during titration.
[0029] S1-6, the concentration of zirconium dioxide in the sample solution is expressed in "g / l", which is calculated as follows: C=(T×V1) / V2 formula (I) In the formula, C is the concentration of zirconium dioxide, unit g / l; T is the titration degree of EDTA solution, unit g / l; V1 is the volume of EDTA solution consumed, unit ml; V2 is the volume of sample, unit ml.
[0030] The zirconium content in the zirconium raffinate used in this example is 105.46g / l.
[0031] (II) Obtain a standard curve: S3, prepare a standard point solution with zirconium content c: S3-1, first prepare a zirconium matrix stock solution, including the following contents: Take 100 g of zirconium matrix (the hafnium content in the matrix is known), soak in a certain amount of digestion solution (as a reference, the digestion solution is mixed by 36 ml of 70% nitric acid + 8 ml of 49% hydrofluoric acid + 36 ml of pure water) at room temperature 20~27℃ for 1~2 min, and then wash with ultrapure water. This step is to eliminate the surface oxides and contaminants of the zirconium matrix to ensure the accuracy of the zirconium matrix. After drying, add acid solution (as a reference, the acid solution is mixed by 100 ml of 70% nitric acid + 300 ml of 49% hydrofluoric acid and 400 ml of pure water) to dissolve and fix in a 1000 ml polytetrafluoroethylene volumetric flask. The zirconium content in the zirconium matrix stock solution is 100 g / l.
[0032] S3-2, combine the above zirconium matrix stock solution and the purchased hafnium standard solution (optional concentration is 1000 ppm) to prepare a standard point solution with a zirconium content of c, including the following contents: (1) Prepare a blank point: take 10 ml of zirconium matrix stock solution (100 g / l) in a 100 ml volumetric flask, and dilute to 100 ml with pure water.
[0033] (2) Prepare standard point 1 (i.e. 1 ppm standard curve point): take 10 ml of zirconium matrix stock solution (100 g / l) and 0.1 ml of 1000 ppm hafnium standard solution in a 100 ml volumetric flask, and dilute to 100 ml with pure water.
[0034] (3) Prepare standard point 2 (i.e. 2 ppm standard curve point): take 10 ml of zirconium matrix stock solution (100 g / l) and 0.2 ml of 1000 ppm hafnium standard solution in a 100 ml volumetric flask, and dilute to 100 ml with pure water.
[0035] (4) Prepare standard point 3 (i.e. 5 ppm standard curve point): take 10 ml of zirconium matrix stock solution (100 g / l) and 0.5 ml of 1000 ppm hafnium standard solution in a 100 ml volumetric flask, and dilute to 100 ml with pure water.
[0036] As an improvement, the source of hafnium elements in the above standard point solution includes hafnium standard solution and zirconium matrix stock solution. This scheme fully considers the hafnium elements in the zirconium standard stock solution, which can make the detection result closer to the actual value and has higher accuracy.
[0037] S3, detect and fit the standard curve: sample and detect the above standard point solution in the inductively coupled plasma spectrometer, and perform data fitting on the intensity measured by the instrument and the preset hafnium concentration in the standard point solution to obtain the standard curve; S3-1, before sampling and detection, also includes spectrum line selection, including the following contents: use the instrument to measure the purchased hafnium standard solution, and select the hafnium element spectrum line according to the instrument measurement result, according to the principle of high signal-to-noise ratio, moderate sensitivity and small matrix interference.
[0038] As a reference, the instrument used in this embodiment is a SPECTRUM 2000 ICP-OES. The purchased hafnium standard solution is measured by the instrument. The signal-to-noise ratio, sensitivity and matrix interference of the element spectral line in the instrument spectrum are compared, and the hafnium element spectral line is selected according to the principle of high signal-to-noise ratio, moderate sensitivity and small matrix interference. In this embodiment, 264.141 nm is specifically selected. The hafnium content in the above-mentioned standard point solution (such as the blank point and standard point in S2) is detected at the spectral line.
[0039] S3-2, standard curve and slope: the intensity measured by the inductively coupled plasma optical spectrometer is data-fitted with the preset concentration, and the obtained standard curve equation is y (emission intensity) = k (slope) * x (standard solution concentration) + b (intercept). The linear slope is greater than 0.999, and the curve is as shown in Figure 1 , which meets the linear fitting requirements.
[0040] In fitting the standard curve, the source of hafnium element in the standard point solution is fully considered, that is, the source of hafnium element in the standard point solution includes hafnium standard solution and zirconium matrix stock solution. In other words, the hafnium content in the zirconium standard stock solution (zirconium content is 100 g / l) used in this scheme is 4.3 ppm, so that the abscissa of the four standard points (as shown in Figure 1 ) obtained by fitting the standard curve is 0.43 ppm, 1.43 ppm, 2.43 ppm and 5.43 ppm. It fully considers the hafnium element in the zirconium standard stock solution, so that the detection result is closer to the actual value and the accuracy is higher.
[0041] (Three) Determination of hafnium content in zirconium raffinate: S4, dilute the zirconium raffinate to be detected, including the following contents: Accurately take the zirconium raffinate sample into a clean 100 ml capacity bottle, add 5 ml of digestion solution (as above), and dilute to the mark with pure water, shake well (according to the concentration of zirconium in the sample solution, dilute appropriately, in this embodiment, the concentration c of zirconium in the diluted zirconium raffinate sample solution is 10 g / l, in fact, under normal error, the zirconium content in the diluted zirconium raffinate is 10±0.1 g / l, and the detection result is still relatively accurate). The volume of the zirconium raffinate sample taken during dilution is calculated according to the following formula: V=1350 / C formula (two) In the formula, V is the volume of the zirconium raffinate sample taken, in ml; C is the zirconium dioxide content in the sample detected by EDTA titration method, in g / l.
[0042] S5, refer to the method in S3 to sample and detect the diluted zirconium raffinate in S4, and bring into the standard curve in S3 to obtain the hafnium content in the diluted zirconium raffinate.
[0043] Specifically, the hafnium content in the zirconium raffinate to be detected in the embodiment is 45 ppm.
[0044] Experimental Example 1: Determination of detection limit The detection limit is determined by testing the blank sample for three non-consecutive days. According to the Global Environment Monitoring System Operation Guide EPA SW-846, the detection limit MDL = S*t (n-1, 0.99). When the number of parallel tests n = 7, the t value is 3.14. The standard deviation S obtained from 21 sets of data obtained by testing for three non-consecutive days in this scheme is 0.9 ppm (the specific test values are shown in Table 1); specifically, the detection limit MDL of the detection method in this scheme is 3.14*0.9 = 3 ppm (rounded).
[0045] Table 1: Test data for three non-consecutive days
[0046] Experimental Example 2: Accuracy verification of the method The prepared verification samples with different zirconium matrices were tested for three non-consecutive days. The hafnium content in the blank sample with known matrix was 0.43 ppm, and the standard addition was 1 ppm. The dilution factor was 100 times, and 21 tests were performed for three non-consecutive days. The control limit of the blank sample + (the standard addition sample ± 10%) was verified, i.e., the upper control limit in this experiment was 153 ppm, and the lower control limit was 133 ppm). The results are shown in Table 2, which show that the detection results are within the theoretical control limit, indicating that the method has high accuracy and stability. Figure 2
[0047] Comparative Example 1: Different spectral line selection when using other instruments for detection Different instruments were used for testing, and the spectral line selection method in this scheme was used for spectral line selection, which was consistent with the software recommended spectral line. The hafnium element was tested by standard addition, and the standard curve and sample recovery rate were observed to verify the feasibility of the spectral line (the results are shown in Table 2).
[0048] Table 2: Analysis of spectral lines for different instrument tests
[0049] The results show that using different instruments, the method in this scheme can detect the hafnium content in the zirconium raffinate, and the accuracy is high.
[0050] Comparative Example 2: Standard addition method shows that the stability of the detection results is general Comparing the standard addition method and the matrix assignment external standard method used in this scheme, first, the accuracy verification was performed, and the results are shown in Table 3, which show that the accuracy of the results of the two methods is close.
[0051] Table 3: The accuracy of the results of the two methods is close
[0052] The stability verification was carried out again, and the known standard sample was repeatedly tested for 2 hours (tested every 10 minutes), and the results are shown in Table 4, which shows that the matrix-assigned external standard method is better than the standard addition method in stability test.
[0053] Table 4 Results of repeated testing of known standard sample for 2 hours (tested every 10 minutes)
[0054] In summary, the matrix-assigned external standard method is recommended based on the accuracy and stability verification results of the two methods, which can maintain the long-term stability of the standard sample and the results.
[0055] Comparative Example 3: Standard "external standard method" detection without extension Comparing the ordinary external standard method with the matrix-assigned external standard method, the accuracy of the test results was compared whether the matrix concentration was added in the standard curve or not, and the results are shown in Table 5.
[0056] Table 5 Comparison results of ordinary external standard method and matrix-assigned external standard method
[0057] The results show that by comparing the two methods, it can be determined that the known matrix concentration needs to be added with the assigned value in the standard curve, and the test results are more accurate and close to the true value.
[0058] The above is only an embodiment of the present application, and the specific technical solutions and / or common knowledge of the scheme are not described in detail. It should be noted that for those skilled in the art, without departing from the technical solutions of the present application, some modifications and improvements can be made, which should also be considered as the protection scope of the present application, which will not affect the effect and practicality of the patent. The protection scope of the present application should be subject to the content of its claims, and the specific implementation mode and the like in the specification can be used to explain the content of the claims.
Claims
1. A method for detecting hafnium content in zirconium raffinate, characterized by: It comprises the following steps: (I) Determining the zirconium content in the zirconium raffinate: S1, dispersing the zirconium raffinate sample in dilute hydrochloric acid, and determining the zirconium dioxide content in the sample solution by EDTA titration method; (II) Obtaining a standard curve: S2, preparing a standard point solution with a zirconium content of c: selecting a zirconium substrate with a known hafnium content, treating it with acid and water, dissolving it with acid and diluting it to a zirconium substrate stock solution; combining the zirconium substrate stock solution with the purchased hafnium standard solution to prepare several standard point solutions; S3, detecting and fitting the standard curve: sample detection of the above standard point solution in an inductively coupled plasma spectrometer, data fitting of the instrument-determined intensity and the pre-set hafnium concentration in the standard point solution, and obtaining the standard curve; (III) Determining the hafnium content in the zirconium raffinate: S4, diluting the zirconium raffinate: diluting the zirconium raffinate sample to make its zirconium content and acid concentration consistent with the standard point solution in S2; S5, sample detection of the diluted zirconium raffinate in S4 by referring to the method in S3, and obtaining the hafnium content in the diluted zirconium raffinate by using the standard curve in S3.
2. The method for detecting hafnium content in zirconium raffinate according to claim 1, characterized in that: In S3, before sample detection, it also includes spectrum line selection, which includes the following contents: using the purchased hafnium standard solution to determine the instrument, and selecting the hafnium element spectrum line according to the instrument determination results, the principle of high signal-to-noise ratio, moderate sensitivity and small matrix interference.
3. The method for detecting hafnium content in zirconium raffinate according to claim 1, characterized in that: In S2, the zirconium substrate includes any one of metal zirconium substrate, zirconium compound substrate and zirconium alloy substrate.
4. The method for detecting hafnium content in zirconium raffinate according to claim 1, characterized in that: In S2, the hafnium content in the standard point solution is 0 ppm, 1 ppm, 2 ppm and 5 ppm respectively, the appropriate spectrum line wavelength is selected by inductively coupled plasma emission spectrometer, the concentration and intensity are linearly related, and the hafnium content in the zirconium raffinate is accurately quantitatively analyzed.
5. The method for detecting hafnium content in zirconium raffinate according to claim 1, characterized in that: In S2, the source of hafnium element in the standard point solution includes hafnium standard solution and zirconium substrate stock solution.
6. The method for detecting hafnium content in zirconium raffinate according to claim 1, characterized in that: In S1 and S2, the concentration of dilute hydrochloric acid solution is 3.7%.
7. The method for detecting hafnium content in zirconium raffinate according to claim 1, characterized in that: In S2, the pickling treatment is to use a digestion solution to pickle the zirconium substrate at room temperature 20-27℃ for 1-2min, and the digestion solution is composed of 70% nitric acid, 49% hydrofluoric acid and pure water in a volume ratio of 34-38:7-9:
36.
8. The method for detecting hafnium content in zirconium raffinate according to claim 1, characterized in that: In S2, the acid solution is composed of 70% nitric acid, 49% hydrofluoric acid and pure water in a volume ratio of 100:295-305:395-405.
9. The method for detecting hafnium content in zirconium raffinate according to claim 1, characterized in that: The deviation of zirconium content c in the zirconium raffinate sample and the zirconium content c in the standard point solution is less than or equal to 1%; the zirconium content c is 2-10g / l.
10. The method for detecting hafnium content in zirconium raffinate according to claim 1, characterized in that: The detection limit of the method is determined by testing the blank sample for three days, and the detection limit is 3ppm, and the detection range is 3-500ppm.