Methods for testing element content

Abstract

A method for testing elemental content includes the following steps: determining a final calibration curve, which is a curve reflecting the relationship between the fluorescence intensity of a target metal element in a liquid metal sample and the content of the corresponding target metal element in a precursor prepared from the liquid metal sample; measuring the fluorescence intensity of each metal element in the liquid metal sample using X-ray fluorescence spectroscopy, and determining the content of each metal element in the precursor obtained from the liquid metal sample based on the fluorescence intensity. This method can determine whether the metal content in the product meets the process requirements by detecting the metal content in the precursor liquid metal, improving detection efficiency and product yield.

Description

Technical Field

[0001] This invention relates to the field of precursor component analysis technology, and in particular to a method for testing elemental content. Background Technology

[0002] Precursors, especially nickel-cobalt-manganese ternary precursors, are the main raw materials for producing cathode materials. During production, it is necessary to measure the content of major metallic elements in the precursor, such as nickel, cobalt, and manganese, to determine whether the product meets design requirements.

[0003] In existing technologies, X-ray fluorescence spectrometry (XRF) is generally used to detect the produced precursors. In actual production, fluorescence intensity-content standard curves can be established for each metal element based on past experience. When measuring the precursor, XRF is used to detect the precursor, obtaining the fluorescence intensity of each metal element. Then, based on the standard curve, the content of that metal in the precursor solid can be determined.

[0004] However, this method involves testing the product itself. Since the product has already been produced in the reactor during the testing process, the results are often delayed, leading to low testing efficiency. If the product does not meet production requirements, subsequent production processes need significant modifications, resulting in a lower yield for that batch. Summary of the Invention

[0005] In view of this, the present invention provides a method for testing elemental content. This method can determine whether the metal content in the product meets the process requirements by detecting the metal content in the precursor metal liquid, thereby improving detection efficiency and product yield.

[0006] This invention provides a method for testing elemental content, comprising the following steps: The final calibration curve is determined, which is the relationship between the fluorescence intensity of the target metal element in the metal liquid sample and the content of each metal element in the precursor prepared from the metal liquid sample. X-ray fluorescence spectroscopy was used to measure the fluorescence intensity of the metal liquid sample to be tested, and the content of each metal element in the precursor obtained from the metal liquid sample was obtained based on the fluorescence intensity.

[0007] Furthermore, in determining the final calibration curve, the method includes the following steps; S11: Provides multiple standard liquid metal samples; S12: The standard liquid metal samples are tested using X-ray fluorescence spectroscopy to detect the fluorescence intensity of each sample. Based on the fluorescence intensity of each metal element in each sample and the corresponding content of each metal element, an initial standard curve is established for each metal element. S13: Provide a sample of the liquid metal to be tested, and obtain the content of each metal element in the sample by X-ray fluorescence spectroscopy and an initial standard curve; S14: Prepare a precursor from the liquid metal sample to be tested, and use X-ray fluorescence spectroscopy to detect the precursor calibration sample in order to obtain the fluorescence intensity of each metal element in the precursor calibration sample. S15: Provides a precursor standard curve, and calculates the content of each metal element in the precursor calibration sample based on the fluorescence intensity of each metal element in the precursor calibration sample. S16: Determine whether the deviation between the content of metal elements in the metal liquid sample to be tested and the content of metal elements in the precursor calibration sample is less than the set value. S17: If the deviation is less than the set value, the initial labeled curve is used as the final standard curve; if the deviation is greater than the set value, proceed to step S18. S18: Based on the fluorescence intensity and content of each metal element in the metal liquid sample and precursor, fit the initial standard curve and the precursor standard curve to obtain the fitted curve. Then, using the fitted curve as the initial standard curve, repeat steps S13 to S17 to obtain the final standard curve.

[0008] Furthermore, the standard metal liquid sample is prepared by mixing the metal salts corresponding to each metal element in the standard metal liquid sample.

[0009] Furthermore, the standard liquid metal sample comprises at least four samples.

[0010] Furthermore, in obtaining the precursor standard curve, the method includes the following steps: The precursor standard curve is a curve established in actual production that corresponds to the fluorescence intensity of each metal element in the precursor and the content of each metal element.

[0011] Furthermore, in obtaining the precursor standard curve, the method includes the following steps: The content of each metal element is obtained by performing quantitative chemical analysis on the precursor. X-ray fluorescence spectroscopy was used to detect the same precursor and obtain the fluorescence intensity of each metal element. Establish the correspondence between the fluorescence intensity and content of each metal element.

[0012] Furthermore, when determining whether the deviation between the metal element content in the tested liquid metal sample and the metal element content in the precursor is less than a set value, the deviation is judged using the following formula: Y jn -Y in Where Y jn It represents the molar percentage content of a certain metal element in the precursor; Y in This represents the molar percentage content of the metal element in the molten metal sample to be tested.

[0013] Furthermore, the set value for the deviation is 0.1 mol%.

[0014] Furthermore, when fitting the initial standard curve and the precursor standard curve, the method includes: The fluorescence intensity of the metal element in the metal liquid sample to be tested is fitted with the content of the metal element in the corresponding precursor calibration sample to form fitting data, and the fitting data is used to form a fitting curve.

[0015] Furthermore, when testing standard liquid metal samples or liquid metal samples to be tested by X-ray fluorescence spectroscopy, the volume of the standard liquid metal sample and the liquid metal sample to be tested in the test container shall not be less than 1 / 3 of the volume of their respective containers.

[0016] Another aspect of this application provides the application of the element content testing method described above in the precursor production process.

[0017] In summary, this invention first establishes an initial standard curve for a standard metal solution using X-ray fluorescence spectrometry. Then, based on the results obtained for the same test metal solution and its corresponding precursor on the initial and precursor standard curves, the initial and precursor standard curves are fitted to obtain a final standard curve. Subsequently, during detection, the test metal solution can be analyzed using X-ray fluorescence spectrometry and the final standard curve to determine the content of each metal element in the precursor. This allows for rapid determination of whether the metal content in the product meets process requirements, improving detection efficiency and product yield.

[0018] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0019] Figure 1 The diagram shown is a schematic of the initial standard curve.

[0020] Figure 2 The figure shows a schematic diagram of the distribution of the liquid sample to be tested on the initial standard curve.

[0021] Figure 3 The diagram shown is a schematic of the precursor standard curve of the precursor.

[0022] Figure 4 The figure shows a schematic diagram of the distribution of the solid sample to be tested on the precursor standard curve.

[0023] Figure 5 The image shows the distribution of the liquid sample after adjustment.

[0024] Figure 6 The figure shown is a schematic diagram of the adjusted standard curve.

[0025] Figure 7 The diagram shows a flowchart of the method for testing elemental content. Detailed Implementation

[0026] To further illustrate the technical means and effects adopted by the present invention in order to achieve the intended purpose, the following detailed description is provided in conjunction with the accompanying drawings and preferred embodiments.

[0027] This invention provides a method for testing elemental content. This method can determine whether the metal content in the product meets the process requirements by detecting the metal content in the precursor molten metal, thereby improving detection efficiency and product yield.

[0028] The present invention provides a method for testing elemental content, which includes the following steps: S1: Determine the final calibration curve, which is a curve reflecting the relationship between the fluorescence intensity of the target metal element in the metal liquid sample and the content of each metal element in the precursor prepared from the metal liquid sample. S2: The fluorescence intensity of each metal element in the liquid metal sample to be tested is obtained by measuring the fluorescence intensity of the sample using X-ray fluorescence spectroscopy. The content of the metal element in the precursor prepared from the liquid metal sample to be tested is then obtained based on the fluorescence intensity.

[0029] The method includes the following steps in determining the final calibration curve: S11: Provides multiple standard liquid metal samples, in which the content of each metal is different.

[0030] In this embodiment, a standard metal liquid sample can be prepared by mixing the metal salts corresponding to each element in the standard metal liquid sample. For example, a standard metal liquid sample can be prepared by mixing nickel sulfate, cobalt sulfate, and manganese sulfate.

[0031] In standard molten metal samples, the ratios of nickel, cobalt, and manganese can be configured using a gradient standard sample based on actual production requirements. The upper and lower limits of this gradient setting generally do not exceed 5% of the required content of each metal element in actual production.

[0032] The purity of the nickel sulfate, cobalt sulfate, and manganese sulfate crystals used was determined by titration, and the weight of each crystal was calculated based on the measured purity.

[0033] Furthermore, in this embodiment, there are at least four standard liquid metal samples. In this embodiment, five samples are used as an example to set the initial standard curve.

[0034] It should be noted that, in this embodiment, the relationship between the fluorescence intensity of each target metal element and the content of the corresponding target metal element in the precursor prepared from the metal liquid sample can be represented on a curve. That is, if there are multiple target metal elements in the precursor, multiple final calibration curves can be determined.

[0035] S12: The standard metal liquid samples are detected by X-ray fluorescence spectroscopy to determine the fluorescence intensity of each sample. Based on the fluorescence intensity of each metal element in each sample and the corresponding content of each metal element, an initial standard curve is established for each metal element. Figure 1 (represented by L1 in Chinese).

[0036] In this embodiment, nickel, cobalt, and manganese can be detected using X-ray fluorescence spectroscopy. For each standard liquid metal sample, the fluorescence intensities corresponding to nickel, cobalt, and manganese are obtained.

[0037] Understandably, there will also be three initial standard curves, with each metal element having its own initial standard curve. Figure 1 The initial standard curve corresponding to one of the metallic elements will be used for illustration.

[0038] In each standard curve, the initial standard curve can be plotted with the fluorescence intensity of the metal element as the x-axis and the content of the metal element as the y-axis.

[0039] exist Figure 1 In, with (X) bn Y bn The expression ) represents the fluorescence intensity and content of a certain metal in a standard liquid metal sample, where n represents the sample number.

[0040] When testing standard liquid metal samples using X-ray fluorescence spectroscopy, the volume of the standard liquid metal sample in the test container is greater than 1 / 3 of the volume of the test container.

[0041] S13: Provide a sample of the liquid metal to be tested, and obtain the content of each metal element in the sample by X-ray fluorescence spectroscopy and an initial standard curve; In this embodiment, the metal liquid sample to be tested can be a precursor pre-liquid prepared in actual production to obtain a precursor, and the precursor pre-liquid may contain metal elements such as nickel, cobalt, and manganese.

[0042] exist Figure 2 In, with (X) in Y in The expression ) represents the fluorescence intensity and content of a certain metal in the liquid metal sample to be tested, where n represents the sample number.

[0043] When testing a liquid metal sample using X-ray fluorescence spectroscopy, the volume of the liquid metal sample in the test container should be greater than 1 / 3 of the container's capacity.

[0044] S14: Prepare a precursor calibration sample from the metal liquid sample to be tested, and detect the precursor calibration sample by X-ray fluorescence spectroscopy to obtain the fluorescence intensity of each metal element in the precursor calibration sample. In this embodiment, the process of preparing the molten metal to be tested as a precursor can be carried out according to one's own actual process, and will not be described in detail here. For ease of measurement, the precursor calibration sample can be prepared as a solid before detection by X-ray fluorescence spectrometry.

[0045] S15: Provides precursor standard curves (see...) Figure 3 (represented by L2), the content of each metal element in the precursor calibration sample is obtained based on the fluorescence intensity of each metal element in the precursor calibration sample; In this embodiment, the precursor standard curve can be a curve established in actual production by producing precursor products, showing the fluorescence intensity of the metal elements in the precursor and the corresponding relationship between each metal element.

[0046] In other embodiments, chemical quantitative analysis can be performed on each metal element in the precursor to obtain the content of each metal element. Then, X-ray fluorescence spectrometry is used to detect the same precursor to obtain the fluorescence intensity of each metal element, and then the correspondence between the fluorescence intensity and content of each metal element is established, finally obtaining the precursor standard curve.

[0047] exist Figure 4 In, with (X) jn Y jn The expression ) represents the fluorescence intensity and content of a certain metal in the liquid metal sample to be tested, where n represents the sample number.

[0048] In this embodiment, since the precursor calibration sample is obtained from the molten metal sample to be tested, the content of each metal element in the precursor calibration sample is directly related to the content of each metal element in the molten metal sample. However, due to the influence of manufacturing process and matrix effect, the content of each metal element in the molten metal sample to be tested obtained according to the standard curve may differ from the content of each metal element in the precursor calibration sample in this step.

[0049] S16: Determine whether the deviation between the content of metal elements in the metal liquid sample to be tested and the content of metal elements in the precursor calibration sample is less than the set value. In this embodiment, the data corresponding to each metallic element can be analyzed, specifically using the following formula: Y jn -Y in Where Y jn To calibrate the molar percentage content of a certain metal element in the precursor sample; Y in This represents the molar percentage content of the metal element in the molten metal sample to be tested.

[0050] The deviation between the metal element content in the metal liquid sample to be tested and the metal element content in the precursor calibration sample is obtained. This deviation can be 0.1 mol%, and in other embodiments, it can be set as needed.

[0051] S17: If the deviation is less than the set value, the initial standard curve is used as the final standard curve. The metal liquid sample to be tested is measured by X-ray fluorescence analysis and the final standard curve. The content of each metal element in the metal liquid sample to be tested reflects the content of each metal element in the precursor. If the deviation is greater than the set value, proceed to step S18. In this embodiment, when the deviation is less than a set value, the molten metal, i.e., the precursor pre-liquid, can be directly collected in subsequent production. Then, X-ray fluorescence analysis is used to measure the fluorescence intensity of each metal element. Based on the fluorescence intensity and the final standard curve, the content of that metal element in the precursor is determined. In other words, the relevant data in the molten metal reflects the content of each metal element in the precursor. This allows for the detection of the content of each metal element in the precursor during the feeding stage of precursor production, quickly determining whether the metal content in the product meets process requirements, improving detection efficiency, and increasing product yield.

[0052] S18: Based on the fluorescence intensity and content of each metal element in the calibration curve of the metal liquid sample and its corresponding precursor, the initial standard curve and the precursor standard curve are fitted to obtain the fitted curve (see...). Figure 6Then, using the fitted curve as the initial standard curve, repeat steps S13 to S17 to obtain the final standard curve.

[0053] In this embodiment, when fitting the initial standard curve and the precursor standard curve, as follows: Figure 5 As shown, the fluorescence intensity of a metal element in the liquid metal sample to be tested can be fitted with the content of that metal element in the corresponding precursor calibration sample to produce new fitting data, that is, this data can be (X... in Y jn And use the fitted data to form a new fitted curve.

[0054] Another aspect of this application provides an application of the element content testing method described above in a precursor production process. Specifically, the application includes a precursor production process using the element content testing method, and production equipment and systems suitable for the precursor production process using the logic of the element content testing method.

[0055] In this invention, an initial standard curve for a standard metal solution is first established using X-ray fluorescence spectrometry. Then, based on the results of the same test metal solution and corresponding precursor calibration sample on the initial and precursor standard curves, the initial and precursor standard curves are fitted to obtain a final standard curve. Subsequently, during detection, the test metal solution can be analyzed using X-ray fluorescence spectrometry and the final standard curve to determine the content of each metal element in the precursor. This allows for rapid determination of whether the metal content in the product meets process requirements, improving detection efficiency and product yield.

[0056] The accuracy of the data obtained by this method will be analyzed below using specific implementation methods.

[0057] Example 1: The method for testing element content provided in this embodiment includes the following steps: S11: This invention prepares standard metal liquid samples with specified metal element contents by using nickel sulfate, cobalt sulfate, and manganese sulfate crystals, setting the upper and lower limits of the main element concentration gradient to ±5% of the actual content fluctuation in the product to be tested. Since the matrix composition of the standard metal liquid samples is consistent with that of the sample to be tested, the influence of matrix effects on the measurement results can be effectively eliminated. Five standard metal liquids with different metal contents were prepared as standard samples; the total content of nickel, cobalt, and manganese in the standard metal liquid samples showed a gradient change.

[0058] The specific steps are as follows: Standard Sample 1: The masses of nickel sulfate, cobalt sulfate, and manganese sulfate crystals are 57.0165, 2.9481, and 0.7902 grams, respectively. Standard Sample 2: The masses of nickel sulfate, cobalt sulfate, and manganese sulfate crystals are 55.4658, 3.9360, and 1.5843 grams, respectively. Standard Sample 3: The masses of nickel sulfate, cobalt sulfate, and manganese sulfate crystals are 54.1577, 3.9544, and 2.4108 grams, respectively. Standard Sample 4: The masses of nickel sulfate, cobalt sulfate, and manganese sulfate crystals are 53.4030, 3.4658, and 2.9150 grams, respectively. Standard sample 5: The masses of nickel sulfate, cobalt sulfate and manganese sulfate crystals are 40.3359, 9.7423 and 8.0294 grams, respectively.

[0059] Place the standard sample (with recorded sample mass) in a 100mL beaker, add an appropriate amount of pure water, and heat and digest in a fume hood. Cover the 100mL beaker with a watch glass until the sample is completely digested. Dilute with an appropriate amount of pure water, rinse the watch glass 3-5 times, and then dilute to volume in a 100mL volumetric flask. Weigh the volumetric flask before and after dilution to ensure that the water addition is controlled throughout the process. Prepare the standard metal liquid sample by weighing.

[0060] S12: Take a metal liquid sample with a volume of 2 / 3 of the sample cup capacity, and test the prepared sample using an X-ray fluorescence spectrometer to obtain the X-ray fluorescence intensity of the metal elements in the standard metal liquid sample. Different elements have characteristic X-ray spectra with different wavelengths, and the content of each metal is directly proportional to its X-ray fluorescence intensity. Establish an initial standard curve L1 using the X-ray fluorescence spectral analysis values ​​and the content of each metal element in the standard solution, and calculate the initial curve fitting coefficients b and a for Ni, Co, and Mn elements respectively. That is, establish the curve C = b × I + a, where C is the content of the metal element and I is the fluorescence intensity.

[0061] S13: Take multiple additional metal liquid samples to be tested, and use the initial standard curve to obtain the fluorescence intensity and content of each metal element in the metal liquid samples to be tested.

[0062] S14: React the liquid metal sample to be tested to produce a finished solid product, and test the precursor solid to obtain the fluorescence intensity data of each metal element in each sample.

[0063] S15: Introduce the precursor standard curve L2, and use the fluorescence intensity data corresponding to each metal element in the precursor and the precursor standard curve to obtain the content of each metal element in the ternary precursor.

[0064] S16, and then by comparing the molar ratio of each element in the target data and the initial data, determine whether the deviation between the content of metal elements in the metal liquid sample to be tested and the content of metal elements in the precursor is less than the set value. S17: If the deviation is less than the set value, then the initial standard curve shall be used as the final standard curve. S18: If the deviation is greater than the set value, the initial standard curve and the precursor standard curve are fitted according to the fluorescence intensity and content of each metal element in the metal liquid sample and the precursor to obtain the fitted curve.

[0065] Through continuous adjustments, the data of the molten metal to be tested and the data of the finished solid product from the reaction were finally made consistent (or the molar ratio deviation was less than 0.1 mol%), thus obtaining the standard curve L3.

[0066] For example, the standard values ​​for nickel in the five standard samples are: 125.98 g / L, 122.56 g / L, 119.67 g / L, 118.00 g / L, and 89.13 g / L.

[0067] Standard curves were established using standard metal liquid samples prepared in the same batch on XRF (X-ray fluorescence spectroscopy) instruments in different laboratories to reduce sample preparation deviations between different laboratories.

[0068] Specifically, firstly, initial curves are established using the same standard liquid metal sample on XRF detection instruments in different laboratories. Secondly, the same liquid metal sample to be tested and the molar ratio of each element are compared with the reaction product precursor, and multiple curve corrections are performed until the deviation between the content of metal elements in the liquid metal sample to be tested and the content of metal elements in the precursor calibration sample is less than the set value.

[0069] X-ray fluorescence spectrometry was used to test the molten metal sample, obtaining the X-ray fluorescence intensity of the metal elements in the sample. The content of the metal elements in the precursor corresponding to the molten metal sample was calculated based on the final standard curve L3. The instrument automatically calculated the molar percentages of nickel, cobalt, and manganese based on the measured metal element content, and the results were rounded to two decimal places.

[0070] The stability of the instrument was analyzed by performing 12 repeated tests on 7 batches of molten metal samples.

[0071] Table 1 Detection stability of X-ray fluorescence spectrometer

[0072] As can be seen from Table 1, the element content testing method provided by the present invention has good stability. The standard deviation (SD) of Ni (mol%) is less than 0.014 mol%, and the 6-fold standard deviation is no greater than 0.084 mol%, which can well meet the detection requirements.

[0073] Example 2 The element content testing method provided in this embodiment is the same as in Embodiment 1, except that the contents of nickel, cobalt, and manganese in the standard metal liquid sample vary in a gradient, but the upper and lower limits of the main element concentration gradient are not limited, and the gradient range of each metal element is larger. The concentrations of the prepared standard solution are as follows: Standard Sample 1: The masses of nickel sulfate, cobalt sulfate, and manganese sulfate crystals are 58.9526, 0.3296, and 0.2079 grams, respectively. Standard Sample 2: The masses of nickel sulfate, cobalt sulfate, and manganese sulfate crystals are 56.5801, 1.5819, and 1.0215 grams, respectively. Standard Sample 3: The masses of nickel sulfate, cobalt sulfate, and manganese sulfate crystals are 47.6276, 6.3116, and 4.0828 grams, respectively. Standard Sample 4: The masses of nickel sulfate, cobalt sulfate, and manganese sulfate crystals are 41.6741, 9.4508, and 6.2393 grams, respectively. Standard sample 5: The masses of nickel sulfate, cobalt sulfate and manganese sulfate crystals are 38.7019, 11.0275 and 7.1380 grams, respectively.

[0074] Place the standard sample (with recorded sample mass) in a 100mL beaker, add an appropriate amount of pure water, and heat and digest in a fume hood. Cover the 100mL beaker with a watch glass until the sample is completely digested. Dilute with an appropriate amount of pure water, rinse the watch glass 3-5 times, and then dilute to volume in a 100mL volumetric flask. Weigh the volumetric flask before and after dilution to ensure that the water addition is controlled throughout the process. Prepare the standard metal liquid sample by weighing.

[0075] Example 3 The element content testing method provided in this embodiment is the same as that in Embodiment 1, except that the initial standard curve L1 is the same as the final standard curve L3.

[0076] Example 4 The element content testing method provided in this embodiment is the same as in Embodiment 1, except that the volume of the liquid metal sample to be tested is 1 / 3 of the sample cup capacity.

[0077] Example 5 The element content testing method provided in this embodiment is the same as in Embodiment 1, except that the volume of the liquid metal sample to be tested is 3 / 4 of the sample cup capacity.

[0078] Comparative Example 1 The method for testing the metal element content in the precursor provided in this comparative example is the industry-standard complexometric titration combined with inductively coupled plasma atomic emission spectrometry (ICP).

[0079] Experimental Example 1 Another standard sample (sample #8) with known elemental contents was selected, and the test methods of Example 1 and Comparative Example 1 were repeated 7 times to test its Ni, Co, and Mn content. The molar content of Ni in sample #8 was 88.01%, the molar content of Co was 5.22%, and the molar content of Mn was 6.77%. The results are shown in Table 2.

[0080] Table 2 Comparison of detection results between Example 1 and Comparative Example 1

[0081] As can be seen from Table 2, the molar ratios of Ni, Co, and Mn elements measured using the method provided in Example 1 are basically consistent with the theoretical values. The detection results obtained in Example 1 are more accurate and stable than those in Comparative Example 1.

[0082] Experimental Example 2 Another standard sample (sample #9) with known elemental contents was selected, and the test methods of Example 1 and Example 2 were repeated 7 times to test its Ni, Co, and Mn content. The molar content of Ni in sample #9 was 88.00%, the molar content of Co was 6.10%, and the molar content of Mn was 5.90%. The results are shown in Table 3.

[0083] Table 3 Comparison of results between Example 1 and Example 2

[0084] As can be seen from Table 3, the molar ratios of Ni, Co, and Mn elements measured in Example 1 are closer to the theoretical values. This invention effectively eliminates the matrix effect during the detection process by preparing standard metal liquid samples with specified metal element contents using nickel sulfate, cobalt sulfate, and manganese sulfate crystals according to the type of product to be tested.

[0085] The matrix effect refers to the influence of components other than the analyte (matrix components) in the sample on the analytical measurement results. These matrix components may alter the signal response of the analyte, causing the measurement results to deviate from the true value.

[0086] Experimental Example 3 The metal element content testing methods in molten metal as described in Examples 1 and 3 were used to repeatedly test the content of Ni, Co, and Mn in the No. 10 molten metal sample seven times. The finished solid product from the No. 10 molten metal sample contained 91.02 mol% Ni, 6.19 mol% Co, and 2.78 mol% Mn. The results are shown in Table 4.

[0087] Table 4 Comparison of results between Example 1 and Example 3

[0088] As can be seen from Table 4, the molar ratios of Ni, Co, and Mn elements measured in Example 1 are closer to those of the solid product. This invention enables the determination of the precursor composition by measuring the molten metal sample.

[0089] Test Example 4 The Ni, Co, and Mn elements in sample 11# were tested using the metal element content testing methods in Examples 1, 4, and 5, respectively, and the results are shown in Table 5.

[0090] Table 5 Comparison of results from Examples 1, 4, and 5

[0091] Table 5 shows that the stability of Examples 1, 4, and 5 in the determination of Ni, Co, and Mn elements is relatively similar, but the stability of Examples 1 and 5 is better than that of Example 4 (indicated by a smaller RSD%). This difference is related to the limited detection depth of X-rays in liquids. When the sample volume is small, the total liquid thickness is thin. If the depth is close to or less than the critical detection depth, the signal will be extremely sensitive to small changes in the liquid layer thickness (such as evaporation, tilting, etc.), thus affecting the stability of the test.

[0092] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for testing element content, characterized in that: Includes the following steps: The final calibration curve is determined, which is a curve reflecting the relationship between the fluorescence intensity of the target metal element in the metal liquid sample to be tested and the content of the corresponding target metal element in the precursor prepared from the metal liquid sample to be tested. X-ray fluorescence spectroscopy was used to measure the fluorescence intensity of each metal element in the metal liquid sample to be tested, and the content of each metal element in the precursor obtained from the metal liquid sample was obtained based on the fluorescence intensity. The method includes the following steps in determining the final calibration curve; S11: Provides multiple standard liquid metal samples; S12: The standard liquid metal samples are tested using X-ray fluorescence spectroscopy to detect the fluorescence intensity of each sample. Based on the fluorescence intensity of each metal element in each sample and the corresponding content of each metal element, an initial standard curve is established for each metal element. S13: Provide a sample of the liquid metal to be tested, and obtain the content of each metal element in the sample by X-ray fluorescence spectroscopy and an initial standard curve; S14: Prepare a precursor calibration sample from the metal liquid sample to be tested, and detect the precursor calibration sample by X-ray fluorescence spectroscopy to obtain the fluorescence intensity of each metal element in the precursor calibration sample. S15: Provides a precursor standard curve, and calculates the content of each metal element in the precursor calibration sample based on the fluorescence intensity of each metal element in the precursor calibration sample. S16: Determine whether the deviation between the content of metal elements in the metal liquid sample to be tested and the content of metal elements in the precursor calibration sample is less than the set value. S17: If the deviation is less than the set value, the initial standard curve is used as the final standard curve; if the deviation is greater than the set value, proceed to step S18. S18: Based on the fluorescence intensity and content of each metal element in the metal liquid sample and the precursor, the initial standard curve and the precursor standard curve are fitted to obtain the fitted curve. Then, using the fitted curve as the initial standard curve, steps S13 to S17 are repeated to obtain the final standard curve. The precursor is a ternary precursor of nickel, cobalt, and manganese.

2. The method for testing elemental content according to claim 1, characterized in that: The standard metal liquid sample is prepared by mixing the metal salts corresponding to each metal element in the standard metal liquid sample.

3. The method for testing elemental content according to claim 1, characterized in that: The standard liquid metal sample shall be at least four.

4. The method for testing elemental content according to claim 1, characterized in that: When obtaining the precursor standard curve, the method includes the following steps: The precursor standard curve is a curve established in actual production that corresponds to the fluorescence intensity of each metal element in the precursor and the content of each metal element.

5. The method for testing elemental content according to claim 1, characterized in that: When obtaining the precursor standard curve, the method includes the following steps: The content of each metal element is obtained by performing quantitative chemical analysis on the precursor. X-ray fluorescence spectroscopy was used to detect the same precursor and obtain the fluorescence intensity of each metal element. Establish the correspondence between the fluorescence intensity and content of each metal element.

6. The method for testing elemental content according to claim 1, characterized in that: When determining whether the deviation between the metal element content in the tested liquid metal sample and the metal element content in the precursor calibration is less than a set value, the deviation is judged using the following formula: AND jn -AND in Where Y jn To calibrate the molar percentage content of a certain metal element in the precursor sample; Y in This represents the molar percentage content of the metal element in the molten metal sample to be tested. And, or, the set value of the deviation is 0.1 mol%.

7. The method for testing elemental content according to claim 1, characterized in that: When fitting the initial standard curve and the precursor standard curve, the method includes: The fluorescence intensity of the metal element in the metal liquid sample to be tested is fitted with the content of the metal element in the corresponding precursor calibration sample to form fitting data, and the fitting data is used to form a fitting curve.

8. The method for testing elemental content according to claim 1, characterized in that: When testing standard liquid metal samples or liquid metal samples to be tested by X-ray fluorescence spectroscopy, the volume of the standard liquid metal sample and the liquid metal sample to be tested in the test container shall not be less than 1 / 3 of the volume of their respective containers.

9. The application of a method for testing elemental content as described in any one of claims 1-8 in the precursor production process.

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