Method for rapidly detecting multiple elements in bentonite by using X-ray fluorescence spectrometer

Abstract

The invention discloses a method for rapidly detecting multiple elements in bentonite by using an X-ray fluorescence spectrometer, and belongs to the technical field of chemical detection. The method comprises the following steps: firstly, drying a national bentonite standard sample to constant weight, cooling, adding into a boric acid bottomed sample pressing machine sample box, pressing into a smooth and clean sample wafer with a flat surface, putting into an X-ray fluorescence spectrophotometer for spectral line scanning, respectively taking spectral line intensities of silicon, aluminum, calcium, magnesium, potassium, sodium, manganese, iron, titanium, phosphorus and sulfur as ordinates and standard contents of all elements of the standard sample as abscissas, and calculating the standard contents of all elements of the standard sample. Establishing a fluorescence standard curve; the method comprises the following steps: preparing a bentonite sample to be detected according to the steps, detecting the spectral line intensities of silicon, aluminum, calcium, magnesium, potassium, sodium, manganese, iron, titanium, phosphorus and sulfur of the bentonite sample to be detected, substituting the spectral line intensities into the fluorescence standard curve, and calculating to obtain the content of each element of the bentonite to be detected. The method is very high in detection accuracy and sensitivity, the analysis period can be shortened, the labor intensity of workers is reduced, the production efficiency is improved, and the analysis cost is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical testing, and in particular relates to a method for rapidly detecting multiple elements in bentonite by using an X-ray fluorescence spectrometer. Background Art

[0002] Bentonite, used as a binder in iron ore pellet production, improves the cohesiveness of iron ore pellets, promotes pellet formation and growth, and enhances the drop strength, compressive strength, and burst temperature of green balls, thereby improving pellet quality. Bentonite quality significantly impacts steelmaking and molten iron quality. For example, high silicon and alkali metal content in bentonite can increase the concentration of harmful elements. Currently, elemental content analysis in bentonite is typically performed using the fusion method, which requires calcination, melting, and molding. This method results in long analysis cycles, high dilution ratios, and significant deviations in elemental analysis. The analysis results from the instrumentation require processing and are susceptible to human interference. Traditional chemical analysis methods require different detection methods for different elements. This involves complex analysis procedures, long test cycles, high operator skills, a wide variety of chemical reagents, and the generation of large amounts of chemical analysis waste, resulting in high testing costs.

[0003] Chinese invention patent CN119880882A discloses a method for determining calcium, magnesium and aluminum in bentonite, which comprises the following steps: (1) weighing a bentonite sample in a polytetrafluoroethylene beaker, adding hydrochloric acid and hydrofluoric acid to dissolve it at low temperature, and preparing a blank sample; (2) adding perchloric acid to the bentonite sample dissolved in step (1) to generate fumes, and cooling it to room temperature; (3) adding hydrochloric acid to the sample cooled in step (2), dissolving salts at low temperature, and cooling it to room temperature; (4) transferring the sample solution obtained in step (3) to a volumetric flask, diluting it to a fixed volume with high-purity water, and shaking it well to obtain a sample solution and a blank sample solution for on-machine detection; (5) introducing the sample solution and the blank sample solution into an inductively coupled plasma emission spectrometer to measure the signal intensity of Ca, Mg and Al ions, and calculating the content of CaO, MgO and Al2O3 in the sample solution based on a calibration curve of a standard solution with known mass percentage. However, this patented detection method still has problems such as a relatively complicated processing process, a relatively small number of detected elements, and a long detection cycle. Therefore, research and development of new methods for rapid detection of multiple elements in bentonite has become an important topic that needs to be studied urgently. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method for rapidly detecting multiple elements in bentonite using an X-ray fluorescence spectrometer. The method of the present invention has a simple operation process, uses fewer chemical reagents, does not generate waste liquid, has a short analysis cycle, and greatly improves the detection efficiency.

[0005] The object of the present invention is to achieve the following goals:

[0006] The present invention provides a method for rapidly detecting multiple elements in bentonite using an X-ray fluorescence spectrometer, comprising the following steps:

[0007] (1) Dry the national standard bentonite sample at a temperature above 100°C to a constant weight, and then cool it in a desiccator;

[0008] (2) Filling the sample box of the sample press with 5-10 g of boric acid as a base, and then spreading 1-3 g of the national standard bentonite sample obtained in step (1) on the surface of the boric acid, and pressing the sample into a smooth and clean surface using the sample press;

[0009] (3) placing the sample prepared in step (2) into an X-ray fluorescence spectrometer for spectral line scanning, respectively detecting the spectral line intensity of silicon, aluminum, calcium, magnesium, potassium, sodium, manganese, iron, titanium, phosphorus, and sulfur in the standard sample, respectively, using the spectral line intensity of silicon, aluminum, calcium, magnesium, potassium, sodium, manganese, iron, titanium, phosphorus, and sulfur as the ordinate and the standard content of each element in the standard sample as the abscissa, respectively establish fluorescence standard curves for silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, potassium oxide, sodium oxide, manganese oxide, iron, titanium dioxide, phosphorus pentoxide, and sulfur;

[0010] (4) Prepare a sample of the bentonite to be tested according to steps (1) to (2), detect the spectral line intensities of silicon, aluminum, calcium, magnesium, potassium, sodium, manganese, iron, titanium, phosphorus, and sulfur in the sample of the bentonite to be tested according to the analytical method of step (3), substitute the intensities into the fluorescence standard curve of step (3), and calculate the contents of silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, potassium oxide, sodium oxide, manganese oxide, iron, titanium dioxide, phosphorus pentoxide, and sulfur in the bentonite to be tested.

[0011] Based on the above technical solution, further, the drying temperature in step (1) is 100-110° C., and the drying time is 0.5-2 h.

[0012] Based on the above technical solution, further, the national standard sample of bentonite described in step (1) has a silicon dioxide content of 30% to 70%, an aluminum oxide content of 10% to 25%, a calcium oxide content of 0.5% to 8%, a magnesium oxide content of 1% to 4%, a potassium oxide content of 0.1% to 2.5%, a sodium oxide content of 0.01% to 9%, a manganese oxide content of 0.02% to 0.12%, an iron content of 1% to 3.5%, a titanium dioxide content of 0.1% to 1%, a phosphorus pentoxide content of 0.005% to 0.25%, and a sulfur content of 0.001% to 0.12%.

[0013] Based on the above technical solution, further, the national standard samples of bentonite described in step (1) include GBW07907, GBW07908, GBW07909 and GBW07910.

[0014] Based on the above technical solution, further, the pressing pressure in step (2) is controlled at 15-25 MPa, and the pressing time is controlled at 5-20 s.

[0015] Based on the above technical solution, further, the X-ray fluorescence spectrometer described in step (3) is a wavelength dispersive X-ray fluorescence spectrometer.

[0016] Based on the above technical solution, further, in step (3), the analysis conditions of silicon dioxide are: the spectrum line is Kα, the detection time is 15 to 25s, the voltage is 45 to 55kV, the current is 45 to 55mA, the crystal is PX4, and the pulse height is 80 to 360; the analysis conditions of aluminum oxide are: the spectrum line is Kα, the detection time is 15 to 25s, the voltage is 45 to 55kV, the current is 45 to 55mA, the crystal is PET, and the pulse height is 110 to 280; the analysis conditions of calcium oxide are: the spectrum line is Kα, the detection time is 15 to 25s, the voltage is 45 to 55 kV, current 45-55mA, crystal LiF, pulse height 130-240; the analysis conditions for magnesium oxide are: spectral line is Kα, detection time is 15-25s, voltage 45-55kV, current 45-55mA, crystal RX35, pulse height 100-300; the analysis conditions for potassium oxide are: spectral line is Kα, detection time is 15-25s, voltage 45-55kV, current 45-55mA, crystal LiF, pulse height 130-250; the analysis conditions for sodium oxide are: spectral line is Kα, detection time is 1 The analysis conditions for manganese oxide are: spectral line is Kα, detection time is 15-25s, voltage is 45-55kV, current is 45-55mA, crystal is RX35, pulse height is 100-350; the analysis conditions for manganese oxide are: spectral line is Kα, detection time is 15-25s, voltage is 45-55kV, current is 45-55mA, crystal is LiF, pulse height is 80-260; the analysis conditions for iron are: spectral line is Kα, detection time is 15-25s, voltage is 45-55kV, current is 45-55mA, crystal is LiF, pulse height is 90-250; the analysis conditions for titanium dioxide are: spectral line is Kα, detection time is 15-25s, voltage is 45-55kV, current is 45-55mA, crystal is LiF, pulse height is 90-250 The analysis conditions for phosphorus pentoxide are: the spectral line is Kα, the detection time is 15-25s, the voltage is 45-55kV, the current is 45-55mA, the crystal is LiF, and the pulse height is 50-240; the analysis conditions for phosphorus pentoxide are: the spectral line is Kα, the detection time is 15-25s, the voltage is 45-55kV, the current is 45-55mA, the crystal is GE, and the pulse height is 70-260; the analysis conditions for sulfur are: the spectral line is Kα, the detection time is 15-25s, the voltage is 45-55kV, the current is 45-55mA, the crystal is NaCl, and the pulse height is 120-260.

[0017] The present invention has the following beneficial effects compared to the prior art:

[0018] 1. The sample processing process of the analysis method of the present invention is simple, the usage of chemical reagents is reduced, and the reagent cost and waste disposal cost are saved.

[0019] 2. The analytical method of the present invention has very high detection accuracy and sensitivity, and can analyze the content of multiple elements in a short time, which can shorten the analysis cycle, reduce employee labor intensity, improve detection capabilities, improve production efficiency, reduce waste liquid discharge, and reduce analysis costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention, the drawings related to the embodiments are briefly introduced below.

[0021] Figure 1 This is a fluorescence standard curve of silicon dioxide in Example 1 (Al has a certain interference on Si detection, so content correction was performed).

[0022] Figure 2 This is the fluorescence standard curve of aluminum oxide in Example 1.

[0023] Figure 3 This is the fluorescence standard curve of calcium oxide in Example 1.

[0024] Figure 4 This is the fluorescence standard curve of magnesium oxide in Example 1.

[0025] Figure 5 This is the fluorescence standard curve of potassium oxide in Example 1.

[0026] Figure 6 This is the fluorescence standard curve of sodium oxide in Example 1.

[0027] Figure 7 This is a fluorescence standard curve of manganese oxide in Example 1.

[0028] Figure 8 This is the fluorescence standard curve of iron in Example 1.

[0029] Figure 9 This is the fluorescence standard curve of titanium dioxide in Example 1.

[0030] Figure 10 This is the fluorescence standard curve of phosphorus pentoxide in Example 1.

[0031] Figure 11 This is the fluorescence standard curve of sulfur in Example 1. DETAILED DESCRIPTION

[0032] The present invention is described in detail below with reference to the embodiments, but the embodiments of the present invention are not limited thereto. Obviously, the embodiments described below are only some embodiments of the present invention. For those skilled in the art, other similar embodiments obtained without creative work all fall within the scope of protection of the present invention.

[0033] Example 1

[0034] This embodiment provides a method for rapidly detecting multiple elements in bentonite using an X-ray fluorescence spectrometer, comprising the following steps:

[0035] (1) 20 g of existing national bentonite standards (GBW07907, GBW07908, GBW07909, and GBW07910) and internal control samples (production samples that meet the particle size requirements and are quantified using chemical analysis methods) were selected and placed in a moisture analyzer and rapidly dried at 105°C to constant weight, and then placed in a desiccator for cooling;

[0036] (2) Fill the sample box of the sample press with 10 g of boric acid as a base, then spread 3 g of the national standard bentonite sample obtained in step (1) on the surface of the boric acid, and press it into a sample with a smooth and flat surface using the sample press (pressure: 18 MPa, time: 15 s);

[0037] (3) placing the sample prepared in step (2) into a wavelength dispersive X-ray fluorescence spectrometer for spectral line scanning, and detecting the spectral line intensities of silicon, aluminum, calcium, magnesium, potassium, sodium, manganese, iron, titanium, phosphorus, and sulfur in the standard sample respectively. The analytical conditions for the X-ray fluorescence spectrometer detection are shown in Table 1. The spectral line intensities of silicon, aluminum, calcium, magnesium, potassium, sodium, manganese, iron, titanium, phosphorus, and sulfur are respectively used as the vertical coordinates and the standard contents of each element in the standard sample are used as the horizontal coordinates. Fluorescence standard curves of silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, potassium oxide, sodium oxide, manganese oxide, iron, titanium dioxide, phosphorus pentoxide, and sulfur are respectively established;

[0038] Table 1. Analytical conditions for X-ray fluorescence spectrometry

[0039]

[0040]

[0041] (4) Prepare a sample of bentonite to be tested according to steps (1) to (2), detect the spectral line intensity of silicon, aluminum, calcium, magnesium, potassium, sodium, manganese, iron, titanium, phosphorus, and sulfur in the sample of bentonite to be tested according to the analytical method of step (3), substitute the spectral line intensity into the fluorescence standard curve, and calculate the content of silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, potassium oxide, sodium oxide, manganese oxide, iron, titanium dioxide, phosphorus pentoxide, and sulfur in the bentonite to be tested. Each sample is tested 5 times.

[0042] Two bentonite samples were independently tested according to the method of this example. The test results are shown in Table 2 and compared with the results of traditional chemical analysis.

[0043] Table 2. Test results of the content of each element in the bentonite to be tested

[0044]

[0045]

[0046] Note: In traditional chemical analysis methods, the contents of silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide and iron are detected by X-ray fluorescence spectrometry cast glass disc method; the contents of potassium oxide and sodium oxide are detected by atomic absorption spectrometry; the contents of manganese oxide, titanium dioxide and phosphorus pentoxide are detected by ICP method; the sulfur content is detected by infrared carbon-sulfur method.

[0047] Example 2

[0048] This embodiment provides a method for rapidly detecting multiple elements in bentonite using an X-ray fluorescence spectrometer, comprising the following steps:

[0049] (1) 20 g of existing national bentonite standards (GBW07907, GBW07908, GBW07909, and GBW07910) and internal control samples (production samples that meet the particle size requirements and are quantified using chemical analysis methods) were selected and placed in a moisture analyzer and rapidly dried at 105°C to constant weight, and then placed in a desiccator for cooling;

[0050] (2) Fill 8 g of boric acid into the sample box of the press to make a base, then spread 5 g of the national standard bentonite sample obtained in step (1) on the surface of the boric acid, and press the sample into a smooth and clean sample using the press (pressure: 20 MPa, time: 15 s);

[0051] (3) placing the sample prepared in step (2) into a wavelength dispersive X-ray fluorescence spectrometer for spectral line scanning, and detecting the spectral line intensities of silicon, aluminum, calcium, magnesium, potassium, sodium, manganese, iron, titanium, phosphorus, and sulfur in the standard sample, respectively. The analytical conditions for the X-ray fluorescence spectrometer detection are shown in Table 3. The spectral line intensities of silicon, aluminum, calcium, magnesium, potassium, sodium, manganese, iron, titanium, phosphorus, and sulfur are used as the ordinate, and the standard content of each element in the standard sample is used as the abscissa, respectively. Fluorescence standard curves of silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, potassium oxide, sodium oxide, manganese oxide, iron, titanium dioxide, phosphorus pentoxide, and sulfur are established;

[0052] Table 3. Analytical conditions for X-ray fluorescence spectrometry

[0053] element spectral lines Measuring time / s Voltage / kV Current / mA crystals Pulse Height PHA silicon Kα 20 50 50 PX4 80-360 aluminum Kα 20 50 50 PET 110-280 calcium Kα 20 50 50 LiF 130-240 magnesium Kα 20 50 50 RX35 100-300 potassium Kα 20 50 50 LiF 130-250 sodium Kα 20 50 50 RX35 100-350 manganese Kα 20 50 50 LiF 80-260 iron Kα 20 50 50 LiF 90-250 titanium Kα 20 50 50 LiF 50-240 phosphorus Kα 20 40 50 GE 70-260 sulfur Kα 20 50 50 NaCl 120-260

[0054] (4) Prepare a sample of bentonite to be tested according to steps (1) to (2), detect the spectral line intensity of silicon, aluminum, calcium, magnesium, potassium, sodium, manganese, iron, titanium, phosphorus, and sulfur in the sample of bentonite to be tested according to the analytical method of step (3), substitute the spectral line intensity into the fluorescence standard curve, and calculate the content of silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, potassium oxide, sodium oxide, manganese oxide, iron, titanium dioxide, phosphorus pentoxide, and sulfur in the bentonite to be tested. Each sample is tested 5 times.

[0055] Two bentonite samples were independently tested according to the method of this example. The test results are shown in Table 4 and compared with the results of traditional chemical analysis.

[0056] Table 4. Test results of the content of each element in the bentonite to be tested

[0057]

[0058] Note: In traditional chemical analysis methods, the contents of silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide and iron are detected by X-ray fluorescence spectrometry cast glass disc method; the contents of potassium oxide and sodium oxide are detected by atomic absorption spectrometry; the contents of manganese oxide, titanium dioxide and phosphorus pentoxide are detected by ICP method; the sulfur content is detected by infrared carbon-sulfur method.

[0059] In summary, the analytical method of the present invention has very high detection accuracy and sensitivity, can analyze the content of multiple elements in a short time, can shorten the analysis cycle, reduce employee labor intensity, improve detection capabilities, improve production efficiency, reduce waste liquid discharge, and reduce analysis costs.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for rapidly detecting multiple elements in bentonite using an X-ray fluorescence spectrometer, characterized in that: The steps include: (1) Dry the national standard bentonite sample at a temperature above 100°C to a constant weight, and then cool it in a desiccator; (2) Filling the sample box of the sample press with 5-10 g of boric acid as a base, and then spreading 1-3 g of the national standard bentonite sample obtained in step (1) on the surface of the boric acid, and pressing the sample into a smooth and clean surface using the sample press; (3) placing the sample prepared in step (2) into an X-ray fluorescence spectrometer for spectral line scanning, respectively detecting the spectral line intensity of silicon, aluminum, calcium, magnesium, potassium, sodium, manganese, iron, titanium, phosphorus, and sulfur in the standard sample, respectively, using the spectral line intensity of silicon, aluminum, calcium, magnesium, potassium, sodium, manganese, iron, titanium, phosphorus, and sulfur as the ordinate and the standard content of each element in the standard sample as the abscissa, respectively establish fluorescence standard curves for silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, potassium oxide, sodium oxide, manganese oxide, iron, titanium dioxide, phosphorus pentoxide, and sulfur; (4) Prepare a sample of the bentonite to be tested according to steps (1) to (2), detect the spectral line intensities of silicon, aluminum, calcium, magnesium, potassium, sodium, manganese, iron, titanium, phosphorus, and sulfur in the sample of the bentonite to be tested according to the analytical method of step (3), substitute the intensities into the fluorescence standard curve of step (3), and calculate the contents of silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, potassium oxide, sodium oxide, manganese oxide, iron, titanium dioxide, phosphorus pentoxide, and sulfur in the bentonite to be tested.

2. The method according to claim 1, characterized in that The drying temperature in step (1) is 100-110° C., and the drying time is 0.5-2 h.

3. The method according to claim 1, characterized in that The national standard sample of bentonite described in step (1) has a silicon dioxide content of 30% to 70%, an aluminum oxide content of 10% to 25%, a calcium oxide content of 0.5% to 8%, a magnesium oxide content of 1% to 4%, a potassium oxide content of 0.1% to 2.5%, a sodium oxide content of 0.01% to 9%, a manganese oxide content of 0.02% to 0.12%, an iron content of 1% to 3.5%, a titanium dioxide content of 0.1% to 1%, a phosphorus pentoxide content of 0.005% to 0.25%, and a sulfur content of 0.001% to 0.12%.

4. The method according to claim 1, wherein The national standards of bentonite described in step (1) include GBW07907, GBW07908, GBW07909 and GBW07910.

5. The method according to claim 1, wherein The pressing pressure in step (2) is controlled at 15-25 MPa, and the pressing time is controlled at 5-20 s.

6. The method according to claim 1, characterized in that The X-ray fluorescence spectrometer described in step (3) is a wavelength dispersive X-ray fluorescence spectrometer.

7. The method according to claim 1, characterized in that The analysis conditions of silicon dioxide in step (3) are: spectral line is Kα, detection time is 15-25s, voltage is 45-55kV, current is 45-55mA, crystal is PX4, and pulse height is 80-360; the analysis conditions of aluminum oxide are: spectral line is Kα, detection time is 15-25s, voltage is 45-55kV, current is 45-55mA, crystal is PET, and pulse height is 110-280; the analysis conditions of calcium oxide are: spectral line is Kα, detection time is 15-25s, voltage is 45-55kV, current is 45-55 mA, LiF crystal, pulse height of 130-240; the analysis conditions for magnesium oxide are: spectral line is Kα, detection time is 15-25s, voltage is 45-55kV, current is 45-55mA, crystal is RX35, pulse height is 100-300; the analysis conditions for potassium oxide are: spectral line is Kα, detection time is 15-25s, voltage is 45-55kV, current is 45-55mA, crystal is LiF, pulse height is 130-250; the analysis conditions for sodium oxide are: spectral line is Kα, detection time is 15-25s, current is The analysis conditions for manganese oxide are: spectral line is Kα, detection time is 15-25s, voltage is 45-55kV, current is 45-55mA, crystal is LiF, pulse height is 80-260; the analysis conditions for iron are: spectral line is Kα, detection time is 15-25s, voltage is 45-55kV, current is 45-55mA, crystal is LiF, pulse height is 90-250; the analysis conditions for titanium dioxide are: spectral line is Kα, detection time is 15-25s, voltage is 45-55kV, current is 45-55mA, crystal is LiF, pulse height is 90-250 The analysis conditions for phosphorus pentoxide are as follows: Kα, detection time 15-25s, voltage 45-55kV, current 45-55mA, crystal LiF, and pulse height 50-240. The analysis conditions for phosphorus pentoxide are as follows: spectral line Kα, detection time 15-25s, voltage 45-55kV, current 45-55mA, crystal GE, and pulse height 70-260. The analysis conditions for sulfur are as follows: spectral line Kα, detection time 15-25s, voltage 45-55kV, current 45-55mA, crystal NaCl, and pulse height 120-260.

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