A rapid detection method for purity of industrial-grade lanthanum oxide with boric acid as binder

Abstract

This invention discloses a rapid method for detecting the purity of industrial-grade lanthanum oxide using boric acid as a binder, belonging to the field of material purity testing technology. The method involves sampling and mixing samples at a frequency of one batch per trip. The sample is ground to a particle size ≤100μm, then mixed with boric acid at a mass ratio of 1:1-3:1, dried, and filled into a 40mm diameter mold. One to three parallel samples are prepared by pressing under a pressure of 5-30MPa and a holding time of 15-45s, and then sealed and allowed to stand for 1-6 hours. Simultaneously, a lanthanum oxide standard sample with a purity of 90.0%-99.9% is prepared using the same proportion and method. The standard and sample are detected using an X-ray fluorescence spectrometer with a resolution ≤0.1keV, with the La Kα1 characteristic spectral line channel set. The actual purity of the sample is calculated using a standard correction factor. When the relative deviation of the parallel samples is ≤0.5%, the average value is taken as the final result. This invention solves the problems of long detection cycles, low accuracy, and complex operation of traditional methods, reducing the detection cycle to ≤1.5 days. Within hours, the relative standard deviation of the test results is ≤0.30%, and the operation threshold is low.

Description

Technical Field

[0001] This invention relates to the field of material purity testing technology, and in particular to a rapid method for testing the purity of industrial-grade lanthanum oxide using boric acid as a binder. Background Technology

[0002] Lanthanum oxide is a key functional auxiliary material in the production of permanent magnet ferrites, and its purity directly determines the magnetic properties of the ferrite material. Therefore, purity testing of lanthanum oxide upon arrival at the production line is a core aspect of production quality control. Currently, the mainstream methods for testing the purity of lanthanum oxide in the industry are mainly divided into two categories: chemical titration and traditional spectroscopic methods. However, both have significant technical limitations and are difficult to adapt to the high-efficiency and precise requirements of modern industrial production.

[0003] Chemical titration is a traditional and classic detection method. Its principle involves a chemical reaction between a specific reagent and lanthanum oxide, with purity calculated based on reagent consumption. The core problem with this method lies in its cumbersome sample pretreatment, requiring multiple steps such as acid dissolution, filtration, and masking. This not only consumes a large amount of reagent and generates significant waste liquid, but also results in a testing cycle of 2-3 hours. For companies receiving dozens of truckloads of raw materials daily, this is simply unacceptable for rapid batch testing, easily leading to production delays.

[0004] Traditional spectroscopic methods (such as XRF) require no complex digestion and have relatively fast detection speeds, but they suffer from two major bottlenecks: First, the sample has poor formability; lanthanum oxide powder is loose, and direct pressing easily leads to cracks and debris, resulting in unstable fluorescence signal acquisition and significant deviations in detection results. Second, they do not pay enough attention to the standard correction mechanism, relying solely on the instrument's default parameters and ignoring systematic errors caused by matrix effects, making it difficult to guarantee accuracy. Furthermore, commonly used adhesives such as resins and polyvinyl alcohol in existing methods also have significant drawbacks: resin adhesives release irritating odors when heated, classifying them as hazardous waste with high environmental treatment costs; polyvinyl alcohol is hygroscopic, causing deformation of the pressed tablets during detection and affecting detection stability.

[0005] From an operational and cost perspective, existing detection methods have a high operational threshold, requiring 1-2 weeks of professional training for personnel to master key operations such as reagent preparation and instrument calibration, resulting in high human resource training costs. Simultaneously, the cumbersome operating procedures and reagent consumption also drive up unit testing costs. Therefore, developing a simple, rapid, reliable, and environmentally friendly lanthanum oxide purity detection method that is compatible with high-quality adhesives has become an urgent need for ferrite production enterprises to improve quality control efficiency. Summary of the Invention

[0006] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide an industrial-grade rapid detection method for the purity of lanthanum oxide using boric acid as a binder. By optimizing the sample pretreatment process, screening boric acid as the optimal binder and determining the best ratio, optimizing XRF detection parameters, and combining a standard sample correction mechanism, this method achieves efficient (detection cycle ≤ 1.5 hours), accurate (relative standard deviation ≤ 0.30%), and environmentally friendly detection of lanthanum oxide purity, while reducing the operational threshold and detection cost, and meeting the rapid inspection needs of batch raw materials entering the industrial production process.

[0007] To solve the above technical problems, the technical solution of the present invention is as follows: A rapid method for determining the purity of industrial-grade lanthanum oxide using boric acid as a binder includes the following steps: (1) Sampling: Lanthanum oxide samples were taken from the incoming vehicles at a frequency of “1 vehicle / time”, and samples from at least 3 different locations were mixed together as the test samples. (2) Sample pretreatment: Grind the sample to be tested into a uniform powder with a particle size ≤100μm, mix it with lanthanum oxide and boric acid in a mass ratio of 1:1-3:1, and then dry it in a constant temperature oven; (3) Tableting preparation: Fill the dried mixture evenly into the tablet press mold, start the tablet press to prepare 1-3 parallel samples. The parallel samples should be 1-5 mm thick, without cracks and without edge defects. Immediately put the parallel samples into a small sealed bag and seal them. Let them stand for 1-6 hours. (4) Standard sample preparation: Select high-purity lanthanum oxide standard sample, and prepare standard sample tablets according to the mass ratio of standard sample to boric acid 1:1-3:1, referring to the method in steps (2)-(3); (5) XRF detection: Start the X-ray fluorescence spectrometer with a resolution ≤0.1keV, preheat for 30 minutes until the instrument is stable, set the detection channel of the characteristic spectral line of lanthanum La Kα1, calibrate the instrument baseline, and then put the standard sample pellet and two parallel samples into the detection station in sequence. Each sample is detected at least once, and the fluorescence purity data of each detection is recorded and the average value is taken. (6) Result calculation: Calculate the correction coefficient K according to the formula K=actual purity of standard sample / fluorescence purity of standard sample, and then calculate the actual purity of the sample according to the formula P=fluorescence purity of sample × K. Calculate the relative deviation of the actual purity of the two parallel samples. If the deviation is ≤0.5%, take the average value as the final detection result; if the deviation is >0.5%, repeat steps (2)-(5).

[0008] The present invention further defines the technical solution as follows: Preferably, in step (2), the sample to be tested is ground into a uniform powder with a particle size ≤100μm, mixed with lanthanum oxide and boric acid at a mass ratio of 1:1-3:1 for 2-10 minutes, and then placed in a constant temperature oven at 100±1℃ to dry for 5-30 minutes.

[0009] Preferably, in step (2), the dried mixture is uniformly filled into a tablet press mold with a diameter of 40 mm, and the tableting pressure is set to 5-30 MPa and the holding time is 15-45 s.

[0010] Preferably, the boric acid is of analytical grade. The boric acid is stored in a sealed container to prevent moisture absorption and clumping. If the boric acid clumps, it needs to be ground into powder before use. When changing brands, the mixing ratio verification experiment needs to be carried out again.

[0011] Preferably, in step (4), a lanthanum oxide standard with a purity of 90.0%-99.9% is selected, and the standard is compressed into tablets according to the method in steps (2)-(3) at a mass ratio of standard to boric acid of 1:1-3:1.

[0012] Preferably, in step (5), each sample is tested 1-3 times, with each test lasting 30-120 seconds. The fluorescence purity data for each test is recorded and the average value is taken.

[0013] Preferably, the grinding mill's inner wall needs to be cleaned after each use to avoid cross-contamination, the tablet press mold needs to be wiped clean after each use, and the X-ray fluorescence spectrometer's accuracy is verified monthly using a standard calibration block. The beneficial effects of this invention are: This invention effectively overcomes the technical bottlenecks of traditional detection methods, significantly improving detection efficiency. The detection cycle for lanthanum oxide is ≤1.5 hours, and the detection accuracy is high, with a relative standard deviation of ≤0.30% for lanthanum oxide detection results and ≤0.5% for rare earth oxide detection results. Combined with a standard sample correction mechanism and optimized tableting process, the stability and reliability of the detection results are greatly improved. By using boric acid as an environmentally friendly binder, the core problems of poor sample formability and easy breakage upon standing in traditional spectroscopic methods are solved. Boric acid has excellent adhesion, and after sealing, the breakage rate of tablets after 12 hours is only about 5%. There are no toxic volatiles, and the used tablets can be treated as general solid waste, avoiding the cost of hazardous waste disposal and reducing reagent and waste liquid consumption, which meets the requirements of green and environmentally friendly detection. At the same time, the entire process is simplified, the parameters are clear and the applicability is wide, the operation threshold is low, and the detection personnel can master it without long-term professional training. The equipment used is conventional industrial equipment and is easy to maintain. Boric acid raw material is readily available and the dosage is reasonable. The unit detection cost is reduced from multiple dimensions such as raw materials, reagents, equipment and manpower, making it both economical and easy to promote. Attached Figure Description

[0014] Figure 1 To accommodate the use of starch-added tablets, the tablets were left to stand for 12 hours after compression. Comparison images before and after compression are shown. Figure 2 Comparison before and after tableting: after the tablets were left to stand for 12 hours following the use of polyvinyl alcohol doping. Figure 3 Comparison before and after tableting, after standing for 12 hours following tableting to use boric acid doping; Figure 4 To accommodate the use of starch as an additive, the tablets were sealed and left to stand for 12 hours after compression. Comparison images before and after compression are shown. Figure 5 To use boric acid doping, the tablets were sealed and left to stand for 12 hours after compression. Comparison images before and after compression are shown. Figure 6 This is a graph showing the linear relationship between lanthanum oxide purity and fluorescence diffraction intensity during the testing process. Detailed Implementation

[0015] To make the content of this invention easier to understand, the invention will be further described in detail below based on specific embodiments. Example 1

[0016] This embodiment describes a rapid determination of lanthanum purity in a batch of industrial-grade lanthanum oxide using boric acid as a binder. The method includes the following steps: (1) Sampling: Lanthanum oxide samples were taken from the incoming vehicles at a frequency of “1 vehicle / time”, and samples from at least 3 different locations were mixed together as the test samples. (2) Sample pretreatment: Grind the sample to be tested into a uniform powder with a particle size ≤ 80 μm, weigh 15.00 g of sample and mix with 5.00 g of boric acid for 5 minutes, and then put it into a constant temperature oven at 100 ℃ to dry for 5 minutes; (3) Tableting preparation: The dried mixture is evenly filled into a 40 mm tableting mold, the tableting pressure is set to 20 MPa and the holding time is 30 s. The tableting machine is started to prepare two parallel samples. The parallel samples are 3 mm thick, without cracks and without edge defects. The parallel samples are immediately placed into a small sealed bag and sealed, and left to stand for 2 hours. (4) Standard preparation: Weigh 9.00 g of lanthanum oxide standard (actual purity 99.5%) and 3.00 g of boric acid, and prepare standard tablets according to the methods in steps (2)-(3); (5) XRF detection: Start the X-ray fluorescence spectrometer with a resolution ≤0.1keV, preheat for 30 minutes until the instrument is stable, set the detection channel for the characteristic spectral lines of lanthanum La Kα1, calibrate the instrument baseline, and then place the standard sample pellet and two parallel samples into the detection station in sequence. Each sample is detected twice, and the fluorescence purity data of each detection is recorded and the average value is taken. The average fluorescence purity of the standard sample is 99.48%, and the average fluorescence purity of the parallel samples are 99.35% and 99.38%, respectively. (6) Calculation of results: Correction coefficient K = 99.5% / 99.48%≈1.0002; The actual purity of the parallel samples is 99.35%×1.0002≈99.37% and 99.38%×1.0002≈99.40%, respectively, with a relative deviation of 0.03%≤0.5%, and the final result is the average value of 99.38%.

[0017] Conclusion: The purity of this batch of lanthanum oxide meets the requirements for ferrite production and can be used on-site.

[0018] Example 2

[0019] This example focuses on the incoming inspection of a certain batch of lanthanum oxide, specifically as follows:

[0020] Sampling: For lanthanum oxide trucks entering the site, samples are taken according to the rule of "1 truck / trip". Three samples are selected from different parts of the truck and mixed together as the test samples.

[0021] Sample pretreatment: Grind the blocky sample to be tested to a particle size ≤80μm using a grinder. Accurately weigh 15.00g of sample and 5.00g of boric acid, mix thoroughly for 5 minutes, and then dry in an oven at 100℃ for 15 minutes.

[0022] Tablet preparation: Fill the well-mixed and dried mixture into a mold with a diameter of 40 mm, apply a pressure of 20 MPa and hold for 30 s to prepare two parallel samples, seal the parallel samples and let them stand for 2 hours.

[0023] Standard preparation: Accurately weigh 9.00 g of lanthanum oxide standard (actual purity 99.5%) and 3.00 g of boric acid, and prepare standard tablets using the same method as above.

[0024] XRF detection: Turn on the X-ray fluorescence spectrometer, preheat for 30 minutes, calibrate the baseline, and then detect the standard and parallel samples. The average fluorescence purity of the standard sample was 99.45%, and the average fluorescence purity of the parallel samples were 95.15% and 95.20%, respectively.

[0025] Calculation result: Correction coefficient K = 99.5% / 99.46% ≈ 1.0004.

[0026] The actual purities of the parallel samples were 95.10% × 1.0004 ≈ 95.14% and 95.15% × 1.0004 ≈ 95.19%, respectively.

[0027] Relative deviation ≈ 0.05%, 0.05% ≤ 0.5%.

[0028] The final result is the average, which is (95.14% + 95.19%) ÷ 2 = 95.17%.

[0029] Conclusion: The purity of this batch of lanthanum oxide does not meet the requirements for ferrite production and it cannot be used on site. Example 3

[0030] Basic comparative experiments: Lanthanum oxide standard with a purity of 99.5% was selected as the experimental object. A "no binder" blank group and three binder experimental groups (starch, boric acid, and polyvinyl alcohol) were set up as shown in Table 1. Tablets were prepared according to a fixed ratio of "lanthanum oxide: binder = 1:1" (15.00 g of lanthanum oxide to 15.00 g of binder), following the "Detection Operation Procedure" of this invention. Three parallel samples were prepared for each group. The basic performance of different binders was comprehensively compared using tablet formability (no crack rate), room temperature open-air static stability (tablets placed in air for 12 hours after compression, and cracking observed), and environmental friendliness as core evaluation indicators.

[0031] Optimization and verification experiments: To address the issue of insufficient tablet stability during static storage in the basic experiments, boric acid and starch, which have superior overall performance, were selected as the research objects. The ratio of "lanthanum oxide: binder = 1:1" and the tableting process remained unchanged. A "sealing treatment" step was added (the tablets were immediately placed in a moisture-proof sealed bag after compression). The tablet breakage rate 12 hours after sealing was used as the key indicator to verify the effect of sealing measures on improving static stability. The data are shown in Table 2.

[0032] Table 1

[0033] Table 2

[0034] Based on the data from basic comparative experiments and optimization verification experiments, the performance of each adhesive was comprehensively analyzed from three dimensions: moldability, stability, and environmental friendliness. The results are as follows: 1. Formability Dimension: Due to the lack of adhesive bonding, the crack-free rate of the unbonded group was only 10%, which could not meet the basic requirements for testing. The crack-free rate of the starch group was 86%, the polyvinyl alcohol group was 90%, and the boric acid group reached 93%, significantly higher than the former two. This result indicates that boric acid has a stronger binding effect on lanthanum oxide powder, effectively filling the gaps between powder particles, making the tablet structure more compact, reducing the generation of cracks during the forming process, and providing a stable sample carrier for subsequent testing.

[0035] 2. Static Stability Dimension: This indicator is crucial for ensuring the continuity of the testing process and is analyzed in two scenarios: "open state" and "sealed state." In the open state, all adhesive groups exhibited high breakage rates. While the boric acid group (>50% breakage) was better than the starch group (>70% breakage) and the polyvinyl alcohol group (>80% breakage), it still failed to meet the practical requirement of "samples needing to be stored statically for more than 12 hours" in the testing process. Further analysis of the breakage causes suggests that moisture in the air caused the adhesive to absorb moisture and soften, or that a weak interaction between lanthanum oxide powder and air disrupted the structural stability of the tablet.

[0036] To address this issue, the newly added "sealing treatment" measure in the optimization experiment played a decisive role. Experimental results showed that after sealing, the breakage rate of the boric acid group decreased to only about 5% after 12 hours, while the starch group still had a breakage rate of >50% after sealing. The core reason for this difference is that boric acid itself has weak hygroscopicity, and the sealed environment can effectively isolate it from external moisture, preventing it from absorbing moisture and softening. At the same time, sealing can prevent the internal stress of the tablet from being released more quickly due to contact with air, further maintaining structural stability. Although starch is non-toxic, its structure is more sensitive to moisture, and even sealing cannot completely prevent the migration of residual internal moisture, resulting in a persistently high breakage rate. Polyvinyl alcohol, due to its prominent hygroscopic properties, had already shown significant defects in the basic experiments and was not included in the optimization experiment.

[0037] 3. Environmental Dimension: Both boric acid and starch exhibit good environmental performance, producing no toxic volatile substances. The used tablets can be treated as general solid waste, avoiding the disposal costs of hazardous waste. Polyvinyl alcohol, on the other hand, is prone to moisture absorption and deformation, which not only affects the stability of testing, but also increases the difficulty of solid waste treatment due to its high moisture content in waste tablets.

[0038] In summary, boric acid exhibits the best formability, meets environmental requirements, and its static stability can be significantly improved through a simple and feasible "sealing treatment" (reducing the breakage rate from >50% to 5%), fully satisfying the practical needs of sample storage and batch testing in industrial applications. In contrast, even after optimization, starch and polyvinyl alcohol still have drawbacks beyond insufficient stability and environmental friendliness. Therefore, boric acid was determined to be the optimal binder for lanthanum oxide test samples, and "sealing immediately after tableting" was identified as a necessary step in sample processing. Example 4

[0039] Using a lanthanum oxide standard with a purity of 99.5% as the basic research object, a series of lanthanum oxide samples with theoretical purity gradients of 99.5%, 99%, 98%, 97%, and 96% were constructed by precisely doping and analyzing pure calcium carbonate. Then, 15.00 g of the sample and 5.00 g of boric acid were weighed (weighed strictly according to the optimal ratio of 3:1, with the deviation controlled within ±0.01 g), placed in a mixing container, and thoroughly mixed for 5 minutes using a combination of horizontal shaking and vertical inversion to ensure that there was no local agglomeration of the sample and boric acid. The mixed material was spread evenly on a tray and dried in an oven for 15 minutes. After drying, it was pressed into tablets to prepare two parallel samples, ensuring uniform thickness, no cracks, and no edge defects. The prepared parallel samples were immediately sealed in small airtight bags and allowed to stand for 2 hours. Finally, the sealed and stood parallel samples were placed in an X-ray fluorescence spectrometer. A lanthanum oxide detection curve was constructed with purity as the X-axis and diffraction intensity as the Y-axis. The Pearson correlation coefficient R0 was used to determine the detection curve. 2 Determine its goodness of fit (R) 2 It must be greater than 0.98).

[0040] Sample pretreatment

[0041] If the lanthanum oxide sample to be tested is in lumpy form, grind it into a uniform powder (particle size ≤ 80 μm) using a grinder to ensure consistent sample particle size and avoid affecting the tablet density and fluorescence signal stability. Accurately weigh 15.00 g of lanthanum oxide sample and 5.00 g of boric acid using an electronic analytical balance (weighing strictly according to the optimal ratio of 3:1, with deviation controlled within ±0.01 g), place them in a mixing container, and mix thoroughly for 5 minutes using a combination of horizontal shaking and vertical inversion to ensure that there is no local agglomeration of the sample and boric acid. Spread the well-mixed mixture evenly on a tray and place it in a 100 ℃ constant temperature oven to dry for 15 minutes to remove residual moisture from the sample and prevent moisture from causing tablet cracking or interference with fluorescence signals.

[0042] Tableting preparation

[0043] Take out the dried mixture and fill it evenly into the tablet press mold. Set the tableting pressure to 20 MPa and the holding time to 30 s. Start the tablet press to perform tableting and prepare two parallel samples to ensure that the sample tablets are of uniform thickness, without cracks, and without edge defects. Immediately place the prepared parallel samples into a small sealed bag and seal it. Let it stand for 2 hours to allow the sample to stabilize and avoid the influence of environmental humidity on the sample quality.

[0044] Standard sample processing

[0045] Accurately weigh 9.00 g of lanthanum oxide standard and 3.00 g of boric acid (in a 3:1 ratio) using an electronic analytical balance. Process them in the same way as the "sample pretreatment" and "tablet preparation" steps described above to prepare one standard tablet for subsequent test result correction.

[0046] XRF detection

[0047] Start the X-ray fluorescence spectrometer and preheat it for 30 minutes until the instrument is stable. Select the lanthanum oxide detection curve, enter the number, and place the standard sample pellet and two parallel samples into the instrument detection station in sequence. Detect each sample three times and record the fluorescence purity data of each detection. Take the average value as the fluorescence purity result of the sample.

[0048] Result Calculation

[0049] Correction factor calculation: Based on the known actual purity of the lanthanum oxide standard and the detected fluorescence purity of the standard, the correction coefficient (K) is calculated according to formula (1) to ensure that the detection results eliminate instrument system errors: K = Actual purity of standard sample / Fluorescence purity of standard sample — (1) Sample purity calculation: Substitute the correction factor K into the sample fluorescence purity data, and calculate the actual purity (P) of the sample according to formula (2): P = Sample fluorescence purity × K ——(2)

[0050] Parallel sample verification

[0051] Calculate the relative deviation of the actual purity of the two parallel samples. If the deviation is ≤0.5%, take the average value as the final test result. If the deviation is >0.5%, sample pretreatment, tablet preparation and XRF detection need to be repeated until the deviation meets the requirements.

[0052] In addition to the above embodiments, the present invention may have other implementation methods; all technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by the present invention.

Claims

1. A rapid method for determining the purity of industrial-grade lanthanum oxide using boric acid as a binder, characterized in that: Includes the following steps: (1) Sampling: Lanthanum oxide samples were taken from the incoming vehicles at a frequency of "1 vehicle / time". Samples from at least 3 different locations were mixed together and used as the test sample. (2) Sample pretreatment: Grind the sample to be tested into a uniform powder with a particle size ≤100μm, mix it with lanthanum oxide and boric acid in a mass ratio of 1:1-3:1, and then dry it in a constant temperature oven; (3) Tableting preparation: Fill the dried mixture evenly into the tablet press mold, start the tablet press to prepare 1-3 parallel samples. The parallel samples should be 1-5 mm thick, without cracks and without edge defects. Immediately put the parallel samples into a small sealed bag and seal them. Let them stand for 1-6 hours. (4) Standard sample preparation: Select high-purity lanthanum oxide standard sample, and prepare standard sample tablets according to the mass ratio of standard sample to boric acid 1:1-3:1, referring to the method in steps (2)-(3); (5) XRF detection: Start the X-ray fluorescence spectrometer with a resolution ≤0.1keV, preheat for 30 minutes until the instrument is stable, set the detection channel of the characteristic spectral line of lanthanum La Kα1, calibrate the instrument baseline, and then put the standard sample pellet and two parallel samples into the detection station in sequence. Each sample is detected at least once, and the fluorescence purity data of each detection is recorded and the average value is taken. (6) Result calculation: Calculate the correction coefficient K according to the formula K=actual purity of standard sample / fluorescence purity of standard sample, and then calculate the actual purity of sample according to the formula P=fluorescence purity of sample × K. Calculate the relative deviation of the actual purity of two parallel samples. If the deviation is ≤ 0.5%, take the average value as the final test result. If the deviation is >0.5%, repeat steps (2)-(5).

2. The rapid method for detecting the purity of industrial-grade lanthanum oxide using boric acid as a binder according to claim 1, characterized in that: In step (2), the sample to be tested is ground into a uniform powder with a particle size ≤100μm, mixed with lanthanum oxide and boric acid in a mass ratio of 1:1-3:1 for 2-10 minutes, and then placed in a constant temperature oven at 100±1℃ to dry for 5-30 minutes.

3. The rapid method for detecting the purity of industrial-grade lanthanum oxide using boric acid as a binder according to claim 1, characterized in that: In step (2), the dried mixture is uniformly filled into a tablet press mold with a diameter of 40 mm, and the tableting pressure is set to 5-30 MPa and the holding time is 15-45 s.

4. The rapid method for detecting the purity of industrial-grade lanthanum oxide using boric acid as a binder according to claim 1, characterized in that: The boric acid used is of analytical grade. It should be stored in a sealed container to prevent moisture absorption and clumping. If the boric acid clumps, it should be ground into powder before use. When changing brands, the mixing ratio verification experiment must be performed again.

5. The rapid method for detecting the purity of industrial-grade lanthanum oxide using boric acid as a binder according to claim 1, characterized in that: In step (4), a lanthanum oxide standard with a purity of 90.0%-99.9% is selected, and the standard is compressed into tablets according to the mass ratio of the standard to boric acid of 1:1-3:1, referring to the method in steps (2)-(3).

6. The rapid method for detecting the purity of industrial-grade lanthanum oxide using boric acid as a binder according to claim 1, characterized in that: (5) Each sample is tested 1-3 times, with each test lasting 30-120 seconds. The fluorescence purity data for each test is recorded and the average value is taken.

7. The rapid method for detecting the purity of industrial-grade lanthanum oxide using boric acid as a binder according to claim 1, characterized in that: The grinding machine needs to have its inner wall cleaned after use to avoid cross-contamination. The tablet press mold needs to be wiped clean after each use. The X-ray fluorescence spectrometer needs to have its accuracy verified monthly using a standard calibration block.

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