Method for measuring content of chemical components in siliceous deoxidizer by X-ray fluorescence melting method

Abstract

The invention relates to a method for measuring the content of chemical components in a siliceous deoxidizer by an X-ray fluorescence melting method, which comprises the following steps of: weighing a mixed flux, putting the mixed flux into a platinum gold crucible, dropwise adding ammonium iodide, putting the crucible into a sample melting furnace, and enabling the gradually cooled flux to be attached to the inner wall of the crucible to form a layer of uniform transparent glass-shaped lining layer protective film; weighing lithium carbonate, placing the lithium carbonate in a platinum gold crucible on which wall hanging is completed, and uniformly paving the sample on the lithium carbonate; adding potassium iodide into the crucible subjected to pre-oxidation treatment, and drying for detection; a platinum crucible and a mold need to be cleaned between two times of melting, boiled and soaked for 15 minutes with hot nitric acid, and dried for use after all residual melts are removed through visual inspection; selecting a proper measurement condition; drawing a calibration curve according to the content value of the analysis element in the standard substance and the average value of the measured X-ray fluorescence intensity; according to the invention, the wavelength dispersion X-ray fluorescence spectrometry is used as a research, and the technology replaces a tedious chemical analysis method, so that the detection time is saved, and the detection efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of X-ray fluorescence melting method determination, in particular to a method for determining the content of chemical components in a siliceous deoxidizer by using an X-ray fluorescence melting method. Background Art

[0002] During the steelmaking process, the most direct way to remove excess oxygen from steel is to add ferroalloy deoxidizers. Silica-based multi-component alloys are used as final deoxidizers in steelmaking and have become a key technology in supporting the refining and continuous casting processes. Research and testing are underway to replace ferrosilicon with siliceous deoxidizers. The application of this new product not only improves the deoxidation of molten steel and the removal of deoxidation products, but also reduces the overall cost of steelmaking. To meet the company's production needs and process requirements, a method for testing the silicon, calcium, iron, aluminum, manganese, and phosphorus content of incoming siliceous deoxidizers is required. Research has revealed no relevant standards supporting the chemical composition of siliceous deoxidizers. Reference methods for similar materials include perchloric acid dehydration gravimetric methods, EDTA titration, periodate oxidation spectrophotometry, and phosphomolybdenum blue spectrophotometry. Determination of silicon, calcium, iron, aluminum, manganese, and phosphorus requires separate sample pretreatment and testing, which is time-consuming and labor-intensive, making it difficult to meet the rapid production pace.

[0003] Existing detection technologies do not have any standards for detecting the chemical composition content of siliceous deoxidizers. The detection methods for similar materials are too complicated, and each element needs to be tested one by one. The detection cycle is long, the steps are cumbersome, there are many interference factors, and many reagents are used. Many chemical reagents have an impact on the human body and the environment. In addition, the detection efficiency is low and cannot meet production needs. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a method for determining the content of chemical components in a siliceous deoxidizer by X-ray fluorescence fusion method.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a method for determining the content of chemical components in a siliceous deoxidizer by X-ray fluorescence fusion method, comprising the following steps:

[0006] S1: Weigh the mixed flux into a platinum-gold crucible, add ammonium iodide dropwise, and place the crucible in a melting furnace. When the temperature reaches 1050°C, start shaking and start timing. After melting for 10 minutes, remove the crucibles one by one. When the red color on the outer wall of the removed crucible disappears by two-thirds, quickly and slowly rotate the crucible at a certain tilt angle to allow the gradually cooled flux to adhere to the inner wall of the crucible to form a uniform transparent glass-like inner lining protective film.

[0007] S2: Pre-oxidation treatment: Weigh lithium carbonate and place the sample evenly on the lithium carbonate in a platinum-gold crucible that has been pre-melted. Use a stirring rod to mix the sample and lithium carbonate. Sweep the sample and lithium carbonate attached to the stirring rod into the crucible, and then evenly cover them with mixed flux. Place the crucible in a crucible stand and place it in a muffle furnace. After the pre-melting is completed, there are no black particles in the crucible, indicating a flowable liquid. Remove the crucible and cool it.

[0008] S3: Melt injection: Add potassium iodide to the pre-oxidized crucible, place the crucible in the sample melting furnace and evaporate until there is no liquid. Then put the crucible into the sample melting furnace and put it into the dryer for testing.

[0009] S4: Visual inspection: After the molten sample is prepared, visually inspect the molten sample to see if there are any defects. The defective molten sample is discarded and a qualified molten sample is prepared again;

[0010] S5: Storage of melted samples: put the melted samples into sample bags and quickly put them into the desiccator;

[0011] S6: Cleaning of platinum-gold crucible and mold: Between two melting operations, the platinum-gold crucible and mold need to be cleaned by soaking them in hot nitric acid for about 15 minutes. After visually checking that all remaining melts have been removed, rinse them with tap water and then deionized water, and dry them before use.

[0012] S7: Select appropriate measurement conditions based on the type of instrument used, the type of sample, the analyzed elements, coexisting elements, and their content variation range; select a standard substance sample and follow S1-6 to draw a calibration curve between the content value of the analyzed elements in the standard substance and the average value of the measured X-ray fluorescence intensity.

[0013] As a further improvement of the present invention: in step S1, the mixed flux is a mixture of lithium tetraborate and lithium metaborate in a ratio of 2:1, which is baked at 600° C. for 4 hours and placed in a desiccator for cooling for later use.

[0014] As a further improvement of the present invention: in step S1, a 300 g / L solution of ammonium iodide is used.

[0015] In step S1, the protective film must cover the bottom and sides of the crucible by more than 1 cm.

[0016] As a further improvement of the present invention: the lithium carbonate in step S2 includes the following processing steps: the lithium carbonate is dried at 200° C. for 2 hours, and placed in a desiccator to cool for later use.

[0017] As a further improvement of the present invention: the muffle furnace heating step in step S2 includes gradually heating to 700° C. and then oxidizing for 10 minutes, and then gradually heating to 800° C. to complete pre-melting for 5 minutes.

[0018] As a further improvement of the present invention: in step S3, a 400 g / L potassium iodide solution is used.

[0019] As a further improvement of the present invention: in step S3, after the gas is completely evaporated, the clean platinum gold mold is placed into the furnace. When the temperature rises to 1050°C, the furnace starts to shake and the timing is started. After melting for 10 minutes, the sample is poured into the mold and demolded after the sample cools for 4 minutes.

[0020] Compared with existing technologies, the present invention has the following advantages: a crucible is protected by a flux-coating treatment, the sample is pre-oxidized, and finally, the sample is melt-molded to form a borate glass-like molten sample. The flux selected is a mixed flux of lithium tetraborate and lithium metaborate, lithium carbonate is added as a fluxing agent, and potassium iodide is used as a mold release agent. The silicon, calcium, iron, aluminum, manganese, and phosphorus contents in the sample are calculated based on a calibration curve and measured X-ray intensity. The present invention utilizes wavelength dispersive X-ray fluorescence spectrometry, a technique that replaces cumbersome chemical analysis methods, saves detection time, and improves detection efficiency.

[0021] Secondly, the present invention uses wavelength dispersive X-ray fluorescence spectrometry to determine sample composition, which offers significant advantages over traditional chemical methods. Its accuracy is comparable to that of traditional chemical methods, reducing errors caused by human factors and reagents. This method can simultaneously determine the content of silicon, calcium, iron, aluminum, manganese, and phosphorus in siliceous deoxidizers, eliminating the need to test each element individually. The method is simple and rapid, saving significant amounts of chemical reagents and manpower, significantly improving labor productivity and effectively reducing employee workload. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to illustrate the technical solution more clearly, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] Currently, there are no national or industry-specific testing standards for the chemical composition of siliceous deoxidizers. Consequently, companies often develop their own protocols, often modeled after methods such as perchloric acid dehydration, EDTA titration, periodate oxidation spectrophotometry, and phosphomolybdenum blue spectrophotometry. These methods result in inconsistent standards and poor comparability. Furthermore, pretreatment methods for each element's detection vary, requiring the same sample to undergo multiple pretreatments, including acid digestion, melting, or oxidation. This process is lengthy and prone to operational errors. A single analysis often requires multiple, step-by-step measurements, each of which is time-consuming and resource-intensive, and the overall testing cycle far exceeds the production schedule. Siliceous deoxidizers themselves have a complex matrix, and matrix interference and inter-element interference are easily generated in molten or solution systems, affecting measurement accuracy.

[0027] In order to solve the above problems, the present invention provides a method for determining the content of chemical components in a siliceous deoxidizer by X-ray fluorescence fusion method, comprising the following steps:

[0028] S1: Weigh the mixed flux into a platinum-gold crucible, add ammonium iodide dropwise, and place the crucible in a melting furnace. When the temperature reaches 1050°C, start shaking and start timing. After melting for 10 minutes, remove the crucibles one by one. When the red color on the outer wall of the removed crucible disappears by two-thirds, quickly and slowly rotate the crucible at a certain tilt angle to allow the gradually cooled flux to adhere to the inner wall of the crucible to form a uniform transparent glass-like inner lining protective film.

[0029] S2: Pre-oxidation treatment: Weigh lithium carbonate and place the sample evenly on the lithium carbonate in a platinum-gold crucible that has been pre-melted. Use a stirring rod to mix the sample and lithium carbonate. Sweep the sample and lithium carbonate attached to the stirring rod into the crucible, and then evenly cover them with mixed flux. Place the crucible in a crucible stand and place it in a muffle furnace. After the pre-melting is completed, there are no black particles in the crucible, indicating a flowable liquid. Remove the crucible and cool it.

[0030] S3: Melt injection: Add potassium iodide to the pre-oxidized crucible, place the crucible in the sample melting furnace and evaporate until there is no liquid. Then put the crucible into the sample melting furnace and put it into the dryer for testing.

[0031] S4: Visual inspection: After the molten sample is prepared, visually inspect the molten sample to see if there are any defects. The defective molten sample is discarded and a qualified molten sample is prepared again;

[0032] S5: Storage of melted samples: put the melted samples into sample bags and quickly put them into the desiccator;

[0033] S6: Cleaning of platinum-gold crucible and mold: Between two melting operations, the platinum-gold crucible and mold need to be cleaned by soaking them in hot nitric acid for about 15 minutes. After visually checking that all remaining melts have been removed, rinse them with tap water and then deionized water, and dry them before use.

[0034] S7: Select appropriate measurement conditions based on the type of instrument used, the type of sample, the analyzed elements, coexisting elements, and their content variation range; select a standard substance sample and follow S1-6 to draw a calibration curve between the content value of the analyzed elements in the standard substance and the average value of the measured X-ray fluorescence intensity.

[0035] From flux attachment, pre-oxidation, melt injection molding, to sheet formation, the entire process requires only 10 minutes of high-temperature melting and several minutes of cooling and drying. This significantly shortens sample preparation and testing cycles, and increases testing speed several times over traditional chemical methods. Using standard substance calibration curves, the method's precision and accuracy are comparable to traditional chemical methods such as perchloric acid gravimetric titration and EDTA titration, while eliminating the uncertainty and matrix interference associated with manual endpoint determination. This eliminates the need for significant amounts of chemical reagents, including strong acids, strong oxidants, and organic indicators, reducing laboratory waste generation, minimizing environmental and operator hazards, and saving costs on reagent procurement and waste disposal.

[0036] Drawing on the detection methods of similar materials, the silicon content is determined by melting a mixed flux of sodium hydroxide, anhydrous sodium carbonate and sodium peroxide, dissolving the melt with hydrochloric acid, and converting silicon into insoluble silicic acid with perchloric acid fuming. After filtering and washing, the precipitate is burned at 1000°C to a constant weight, and hydrofluoric acid is added to volatilize the silicon as silicon tetrafluoride, and then burned to a constant weight. The silicon content in the sample is calculated based on the difference in mass before and after hydrofluoric acid treatment; the calcium content is determined by dissolving the sample with nitric acid and hydrofluoric acid, removing fluoride ions with perchloric acid fuming, dissolving the sample with hydrochloric acid, neutralizing with ammonia water, and filtering to separate impurities such as iron. Then, when the pH is not less than 12, a calcium indicator is added and titrated with EDTA standard titration solution. The mass fraction of calcium is calculated based on the consumption of EDTA standard titration solution; the aluminum content is determined by decomposing the sample with nitric acid and hydrofluoric acid, driving out fluorine with perchloric acid fuming, melting the acid-insoluble residue with sodium carbonate-boric acid, and separating the interfering elements twice with hexamethylenetetramine and sodium hydroxide strong base. , add an excess of EDTA to a slightly acidic solution. At a pH of 4.5-5.5, using xylenol orange as an indicator, titrate the excess EDTA with a zinc standard titrant. Then, displace the EDTA complexed with aluminum with fluoride ions, and titrate again with a zinc standard titrant. Calculate the aluminum content in the sample based on the consumption of the zinc standard titrant. For the determination of manganese content, decompose the sample with nitric acid and hydrofluoric acid, remove the fluoride ions with fuming perfluoric acid, oxidize manganese to permanganate with sodium (potassium) periodate in a phosphoric acid medium, and measure its absorbance at a wavelength of 525 nm on a spectrophotometer. The mass of manganese is found on the calibration curve, and the manganese content in the sample is calculated. For the determination of phosphorus content, dissolve the sample with nitric acid and hydrofluoric acid, oxidize the phosphorus to orthophosphoric acid with fuming perchloric acid, reduce the iron with sodium bisulfite, and add ammonium molybdate and hydrazine sulfate to react to form phosphomolybdenum blue. Measure its absorbance at a wavelength of 825 nm on a spectrophotometer. No relevant method support was found for the determination of iron content.

[0037] In order to solve the above problems, the present invention provides a method for determining the content of chemical components in a siliceous deoxidizer by X-ray fluorescence fusion method, comprising the following steps:

[0038] S1: Weigh the mixed flux into a platinum-gold crucible, add ammonium iodide dropwise, and place the crucible in a melting furnace. When the temperature reaches 1050°C, start shaking and start timing. After melting for 10 minutes, remove the crucibles one by one. When the red color on the outer wall of the removed crucible disappears by two-thirds, quickly and slowly rotate the crucible at a certain tilt angle to allow the gradually cooled flux to adhere to the inner wall of the crucible to form a uniform transparent glass-like inner lining protective film.

[0039] S2: Pre-oxidation treatment: Weigh lithium carbonate and place the sample evenly on the lithium carbonate in a platinum-gold crucible that has been pre-melted. Use a stirring rod to mix the sample and lithium carbonate. Sweep the sample and lithium carbonate attached to the stirring rod into the crucible, and then evenly cover them with mixed flux. Place the crucible in a crucible stand and place it in a muffle furnace. After the pre-melting is completed, there are no black particles in the crucible, indicating a flowable liquid. Remove the crucible and cool it.

[0040] S3: Melt injection: Add potassium iodide to the pre-oxidized crucible, place the crucible in the sample melting furnace and evaporate until there is no liquid. Then put the crucible into the sample melting furnace and put it into the dryer for testing.

[0041] S4: Visual inspection: After the molten sample is prepared, visually inspect the molten sample to see if there are any defects. The defective molten sample is discarded and a qualified molten sample is prepared again;

[0042] S5: Storage of melted samples: put the melted samples into sample bags and quickly put them into the desiccator;

[0043] S6: Cleaning of platinum-gold crucible and mold: Between two melting operations, the platinum-gold crucible and mold need to be cleaned by soaking them in hot nitric acid for about 15 minutes. After visually checking that all remaining melts have been removed, rinse them with tap water and then deionized water, and dry them before use.

[0044] S7: Select appropriate measurement conditions based on the type of instrument used, the type of sample, the analyzed elements, coexisting elements, and their content variation range; select a standard substance sample and follow S1-6 to draw a calibration curve between the content value of the analyzed elements in the standard substance and the average value of the measured X-ray fluorescence intensity.

[0045] It realizes the simultaneous rapid determination of multiple elements such as silicon, calcium, iron, aluminum, manganese, and phosphorus in siliceous deoxidizers. It has the advantages of simple operation, short detection cycle, high accuracy, environmental protection and high efficiency. It significantly improves analysis efficiency, reduces the use of chemical reagents, reduces human errors and labor intensity, and meets the actual needs of rapid and accurate detection of deoxidizer components in the steel production process.

[0046] As an embodiment of the present invention, the sample used in the present invention is an analysis sample with a particle size less than 0.125 mm.

[0047] As an embodiment of the present invention, the reagents and materials used in the present invention are as follows:

[0048] P10 gas (a mixture of 90% argon and 10% methane) was used for the flow proportional counter.

[0049] Standard sample: certified reference material.

[0050] Mixed flux: lithium tetraborate and lithium metaborate (2:1) mixed flux, baked at 600°C for 4 hours, placed in a desiccator to cool for use.

[0051] Ammonium iodide (analytical grade): Prepare a 300 g / L solution of ammonium iodide.

[0052] Lithium carbonate (analytical grade): Bake lithium carbonate at 200°C for 2 h and cool in a desiccator for later use.

[0053] Potassium iodide (analytical grade): Prepare a 400 g / L solution of potassium iodide.

[0054] HNO3(1+5).

[0055] As an embodiment of the present invention, the instruments and equipment used in the present invention are as follows:

[0056] The instrument is equipped with fixed and scanning channels, capable of measuring spectral lines. The accuracy of each spectral line test meets the requirements of "JJG 810-1993 Metrological Verification Regulations - Wavelength Dispersive X-ray Fluorescence Spectrometers".

[0057] Automatic melting furnace: can maintain at least 1100℃ and can swing automatically.

[0058] Platinum gold crucible and mold: Crucible 30mL~40mL, the bottom surface of the mold is flat and smooth.

[0059] As a specific embodiment of the present invention, the sample preparation in the present invention includes the following steps:

[0060] Wall hanging treatment: weigh 7.0000g (accurate to 0.0002g) of mixed flux (2.2.2.3) into a platinum-gold crucible, add 1mL of ammonium iodide (2.2.2.4), and then place the crucible into a melting furnace with a temperature of 1050℃. When the temperature rises to 1050℃, start shaking and start timing. After melting for 10 minutes, take out the crucibles one by one. When the red color on the outer wall of the crucible disappears by two-thirds, quickly and slowly rotate the crucible at a certain inclination angle to allow the gradually cooled flux to adhere to the inner wall of the crucible to form a uniform transparent glass-like lining protective film. The protective film must cover the bottom and all sides of the crucible to a height of more than 1cm. The thickness of the bottom of the crucible is not allowed to be uneven. If unsuccessful, the melting and wall hanging operation must be repeated.

[0061] Pre-oxidation treatment: Weigh 1.0000g (accurate to 0.0002g) of lithium carbonate (2.2.2.5) into a platinum-gold crucible that has been wall-mounted. Weigh 0.2000g (accurate to 0.0001g) of sample and evenly spread it on the lithium carbonate. Use a stirring rod to mix the sample and lithium carbonate. Sweep the sample and lithium carbonate attached to the stirring rod into the crucible. Then evenly cover the sample with 1.0000g (accurate to 0.0002g) of mixed flux (2.2.2.3). The amount of mixed flux should be sufficient to completely cover the sample and lithium carbonate mixture. Place the crucible in a crucible holder and place it in a 600°C muffle furnace. Gradually raise the temperature to 700°C and oxidize for 10 minutes. Then gradually raise the temperature to 800°C to complete pre-melting for 5 minutes. After pre-melting, the crucible should be free of black particles and a flowable liquid. Remove and cool.

[0062] Melt mold injection: Add 0.5 mL of potassium iodide (2.2.2.6) to the pre-oxidized crucible, place the crucible at the mouth of the sample melting furnace and evaporate until there is no liquid, then place the crucible in a sample melting furnace with a temperature of 1050°C. After the gas has evaporated, place a clean platinum gold mold into the furnace. When the temperature reaches 1050°C, start shaking and start timing. After melting for 10 minutes, pour the sample into the mold. After the sample cools for 4 minutes, demould it, put the molten sample into a sample bag, mark it, and place it in a desiccator for testing.

[0063] Visual inspection: After the molten sample is prepared, visually inspect it to see if there are any defects such as unmelted material, crystals or bubbles. Defective molten samples should be discarded and a qualified molten sample should be prepared again.

[0064] Storage of molten samples: To prevent the molten samples from absorbing water or being contaminated, put the molten samples into sample bags and quickly put them into the desiccator (when the samples are still warm). Do not touch the analysis surface with your hands and do not handle it in any way, especially do not rinse, grind or polish it with water or other solvents.

[0065] Cleaning the platinum-gold crucible and mold: Between melts, clean the platinum-gold crucible and mold by soaking them in hot nitric acid (1+5) for approximately 15 minutes. Visually inspect to ensure all remaining molten material has been removed. Rinse thoroughly with tap water and then deionized water, allowing them to dry before use. If the mold is clean and free of molten material after demolding, simply wipe it with anhydrous ethanol.

[0066] By accurately weighing the flux, lithium carbonate, and sample mixture (0.0001–0.0002g), and strictly controlling the dosage at each step, the consistency and comparability of each sample preparation are ensured, improving the reproducibility of the measurement results. The flux wall-mounting process forms a glassy protective film ≥1cm thick on the inner wall of the crucible. This not only isolates the sample from direct contact with the crucible, preventing crucible wear, but also ensures uniform heat transfer during the melting process, avoiding localized overburning and carbon deposition. A staged heating process from 600–800°C, followed by pre-oxidation and pre-melting, fully oxidizes and decomposes organic impurities and refractory components, resulting in a black spot-free, highly fluid liquid matrix that provides an optimal melt state for subsequent molding. A predetermined amount of potassium iodide is added as a release agent and rigorously evaporated. After melting for ten minutes, injection molding is performed, followed by a four-minute cooling period and demolding. This produces a glassy melt sample with a smooth surface, free of bubbles and crystal defects, significantly improving the signal-to-noise ratio and measurement accuracy of XRF measurements. The entire sample preparation process (hanging on the wall – pre-oxidation – injection molding – cooling) is standardized and timed, allowing for single-chip preparation within 15–20 minutes, making it suitable for high-frequency, batch sample analysis on-site. Residue between the crucible and mold can be completely removed by simply boiling in hot nitric acid (1+5) for 15 minutes or wiping with anhydrous ethanol. This simple and quick cleaning process minimizes corrosion damage to the platinum crucible and mold. No strong acid or large volumes are used throughout the entire chip preparation process, requiring only small amounts of nitric acid for cleaning, reducing laboratory waste. Sample preparation and demolding are both performed at high temperatures, avoiding the risk of chemical reagent exposure and complying with environmentally friendly requirements.

[0067] As a specific embodiment of the present invention, appropriate measurement conditions are selected based on the instrument type, sample type, analyte, coexisting elements, and their content ranges. The analytical line used, recommended wavelength, spectroscopic crystal, 2Theta, and light tube voltage and current are listed in Table 1.

[0068] Table 1 Measurement conditions

[0069]

[0070] Under the selected working conditions, select a certain number of standard substance samples similar to the analysis sample and perform the above 4 operations. The standard substances are shown in Table 2. Each sample should be measured at least twice. Draw a calibration curve between the content value of the analyzed element in the standard substance and the average value of the measured X-ray fluorescence intensity.

[0071] Table 2 Calibration curve drawing standard material %

[0072]

[0073]

[0074] The X-ray intensity ratio of the analyzed element and the internal standard element in the standard sample was measured, and the working curve was drawn using the intensity ratio relative to the analyzed element content. The calibration curve is shown in Table 3.

[0075] Table 3 Calibration curve

[0076]

[0077] This includes the analysis of unknown samples, which includes instrument drift correction, drift correction confirmation, unknown sample measurement and accuracy experiments.

[0078] Instrument drift correction: Because changes in instrument status can cause deviations in measurement results, drift correction samples are applied to the instrument before analysis to ensure direct use of raw X-ray fluorescence intensity values. A two-point correction is used, and the interval between corrections can be determined based on the stability of the instrument.

[0079] Confirmation of drift correction: Analyze the standard substance after drift correction to confirm that the analysis value is within the tolerance range specified for each component in the chemical analysis method of each standard substance

[0080] Measurement of unknown samples: Based on the sample preparation and selected measurement conditions, the fluorescence intensity of the unknown sample is measured using the selected calibration curve using the corresponding procedure. Before measuring the unknown sample, the standard substance should be measured first. Only after the calibration curve is stable can the unknown sample be measured.

[0081] Accuracy test: Four randomly selected standard samples with a certain gradient and one silica deoxidizer sample were measured according to the unknown sample analysis procedure. Each sample was measured twice, and the average value was compared with the standard allowable deviation. As shown in Table 4, the deviation between the certified value and the measured value is small, meeting the requirements.

[0082] Table 4 Accuracy determination (%) n=2

[0083]

[0084] Precision experiment: One sample was selected and measured 11 times continuously using the method established in this method for precision testing. The relative standard deviation of each element was calculated and the results are listed in Table 5. The relative standard deviation of the content of each element in the sample determined by this method was all below 4%, indicating good data precision and low data deviation, which can meet production requirements.

[0085] Table 5 Precision determination (%) n=11

[0086]

[0087]

[0088] The main functions of the present invention are:

[0089] (1) The mixed flux (Li2B4O7+H3BO3) is melted at 1050℃ and hangs on the wall, forming a uniform glass lining ≥1cm thick. This not only isolates the sample from direct contact with the crucible, extending the service life of the crucible, but also ensures uniform heat conduction and reduces local overburning and carbon deposition.

[0090] (2) Raise the temperature in stages to 600–800°C to assist lithium carbonate in fully oxidizing fusible impurities, ensuring that the melt is free of black spots and has good fluidity, thus providing the best matrix for subsequent injection molding;

[0091] (3) With the help of wavelength dispersive XRF, quantitative signals of six elements, Si, Ca, Fe, Al, Mn, and P, can be quickly obtained on the same glass sample, completely abandoning the traditional "single element single sample" model;

[0092] (4) Using standard sample quantitative calibration, the measurement results are comparable to chemical methods such as perchloric acid gravimetric method and EDTA titration, eliminating the uncertainty caused by manual titration endpoint judgment and matrix interference;

[0093] (5) Shortened sample preparation cycle: The overall sample preparation time is 15–20 minutes, which saves several hours compared with traditional chemical pretreatment and step-by-step determination. The sample preparation and cleaning processes can be standardized and operated in parallel to meet the frequent and multi-batch testing needs of the production site.

[0094] (6) Between two sample preparations, the crucible and the mold only need to be boiled in hot nitric acid (1+5) for 15 minutes or wiped with anhydrous ethanol to completely remove the residue. The cleaning process is simple and has little corrosion to the platinum parts. If the protective film is worn, the flux can be hung on the wall again, without the need to frequently replace the crucible, thus reducing the cost of consumables.

[0095] In summary, after reading the present invention document, ordinary technicians in this field can make various other corresponding transformation schemes based on the technical solutions and technical concepts of the present invention without creative mental work, and all of them fall within the scope of protection of the present invention.

Claims

1. A method for determining the content of chemical components in a siliceous deoxidizer by X-ray fluorescence fusion method, characterized in that: The following steps are involved: S1: Weigh the mixed flux into a platinum-gold crucible, add ammonium iodide dropwise, and place the crucible in a melting furnace. When the temperature reaches 1050°C, start shaking and start timing. After melting for 10 minutes, remove the crucibles one by one. When the red color on the outer wall of the removed crucible disappears by two-thirds, quickly and slowly rotate the crucible at a certain tilt angle to allow the gradually cooled flux to adhere to the inner wall of the crucible to form a uniform transparent glass-like inner lining protective film. S2: Pre-oxidation treatment: Weigh lithium carbonate and place the sample evenly on the lithium carbonate in a platinum-gold crucible that has been pre-melted. Use a stirring rod to mix the sample and lithium carbonate. Sweep the sample and lithium carbonate attached to the stirring rod into the crucible, and then evenly cover them with mixed flux. Place the crucible in a crucible stand and place it in a muffle furnace. After the pre-melting is completed, there are no black particles in the crucible, indicating a flowable liquid. Remove the crucible and cool it. S3: Melt injection: Add potassium iodide to the pre-oxidized crucible, place the crucible in the sample melting furnace and evaporate until there is no liquid. Then put the crucible into the sample melting furnace and put it into the dryer for testing. S4: Visual inspection: After the molten sample is prepared, visually inspect the molten sample to see if there are any defects. The defective molten sample is discarded and a qualified molten sample is prepared again; S5: Storage of melted samples: put the melted samples into sample bags and quickly put them into the desiccator; S6: Cleaning of platinum-gold crucible and mold: Between two melting operations, the platinum-gold crucible and mold need to be cleaned by soaking them in hot nitric acid for 15 minutes. After visually checking that all remaining melts have been removed, rinse them with tap water and then deionized water, and dry them before use. S7: Select appropriate measurement conditions based on the type of instrument used, the type of sample, the analyzed elements, coexisting elements, and their content variation range; select a standard substance sample and follow S1-6 to draw a calibration curve between the content value of the analyzed elements in the standard substance and the average value of the measured X-ray fluorescence intensity.

2. The method for determining the content of chemical components in a siliceous deoxidizer by X-ray fluorescence fusion method according to claim 1, characterized in that: In step S1, the mixed flux is a mixture of lithium tetraborate and lithium metaborate in a ratio of 2:1, baked at 600° C. for 4 hours, and placed in a desiccator for cooling.

3. The method for determining the content of chemical components in a siliceous deoxidizer by X-ray fluorescence fusion method according to claim 2, characterized in that: In step S1, ammonium iodide is used in a 300 g / L solution.

4. The method for determining the content of chemical components in a siliceous deoxidizer by X-ray fluorescence fusion method according to claim 3, characterized in that: In step S1, the protective film must cover the bottom and sides of the crucible by more than 1 cm.

5. The method for determining the content of chemical components in a siliceous deoxidizer by X-ray fluorescence fusion method according to claim 1, characterized in that: The lithium carbonate in step S2 includes the following processing steps: drying the lithium carbonate at 200° C. for 2 hours, and placing it in a desiccator to cool for standby use.

6. The method for determining the content of chemical components in a siliceous deoxidizer by X-ray fluorescence fusion method according to claim 5, characterized in that: In step S2, the muffle furnace heating step includes gradually heating to 700° C. and then oxidizing for 10 minutes, and then gradually heating to 800° C. to complete pre-melting for 5 minutes.

7. The method for determining the content of chemical components in a siliceous deoxidizer by X-ray fluorescence fusion method according to claim 1, characterized in that: In step S3, potassium iodide is used in a 400 g / L solution.

8. The method for determining the content of chemical components in a siliceous deoxidizer by X-ray fluorescence fusion method according to claim 1, characterized in that: In step S3, after the gas evaporates, the clean platinum gold mold is placed in the furnace. When the temperature rises to 1050°C, the furnace starts to shake and the timing is started. After melting for 10 minutes, the sample is poured into the mold and demolded after the sample cools for 4 minutes.

Images