Method for determining element content in alloy based on plasma atomic emission spectrometry and application

Abstract

The invention belongs to the technical field of chemical analysis, and particularly relates to a method for determining the content of elements in an alloy based on plasma atomic emission spectrometry and application. The invention provides a method for measuring element content in alloy based on plasma atomic emission spectrometry, which comprises the following steps: (1) sample pretreatment: mixing a sample to be measured with an acid solution, heating until the sample is dissolved, and collecting a dissolved solution to a constant volume to obtain a sample solution; the acid solution comprises at least one of a sulfuric acid solution and a phosphoric acid solution; (2) preparing standard solutions containing silicon elements and / or aluminum elements with different concentrations, and detecting by utilizing an inductively coupled plasma atomic emission spectrometry technology to obtain a standard curve of the concentration and the spectral intensity of the standard solutions; and (3) respectively calculating the content of the silicon element and / or the aluminum element in the sample solution. The determination method provided by the invention is safe and simple to operate, high in analysis speed, high in precision and good in accuracy.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical analysis, and particularly relates to a method and application for determining the element content in alloys based on inductively coupled plasma atomic emission spectrometry. Background Art

[0002] As important soft magnetic materials and metallurgical raw materials, iron-silicon materials and iron-silicon-aluminum materials have extensive applications in fields such as steel, casting, electric power, aerospace, and automotive manufacturing. During the production process, it is necessary to adjust the formula components to obtain products that are suitable for performance, cost, and the market. The contents of silicon and aluminum need to be monitored at any time to ensure the stability of product quality. Therefore, the timely detection of product components is crucial, and the silicon content in most iron-silicon materials and iron-silicon-aluminum materials is mainly 5%-15%.

[0003] The existing technologies for the determination of silicon mainly include gravimetry and colorimetry. However, both gravimetry and colorimetry have deficiencies such as complex analysis steps, poor stability, and low sensitivity. Inductively coupled plasma optical emission spectrometry (ICP-OES) has the characteristics of fast analysis speed, high sensitivity, wide linear range, and the ability to simultaneously determine multiple elements, and has been widely used in the determination of multiple elements in different types of samples. However, in the existing technologies, hydrofluoric acid is used for sample pretreatment, and the operation process is cumbersome, and it also increases the risk of analysis errors. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects in the prior art such as poor safety, cumbersome steps, and slow analysis speed during the determination of silicon content, so as to provide a method and application for determining the element content in alloys based on inductively coupled plasma atomic emission spectrometry.

[0005] For this purpose, the present invention provides the following technical solutions.

[0006] The present invention provides a method for determining the element content in alloys based on inductively coupled plasma atomic emission spectrometry, comprising the following steps:

[0007] (1) Sample pretreatment: Mix the sample to be measured with an acid solution, heat it until the sample is dissolved, collect the dissolved solution and make it up to a fixed volume to obtain a test solution; the acid solution includes at least one of sulfuric acid solution and phosphoric acid solution;

[0008] (2) Prepare standard solutions containing silicon element and / or aluminum element with different concentrations, detect them by using inductively coupled plasma atomic emission spectrometry analysis technology, obtain the spectral intensities of the standard solutions, and obtain the standard curve of the standard solution concentration and spectral intensity;

[0009] (3) Detect the spectral intensity of the sample solution, and calculate the contents of silicon element and / or aluminum element in the sample solution according to the standard curve obtained in the step (2).

[0010] In an alternative embodiment, the mass content range of silicon element in the sample to be measured is: 0.005 - 15%;

[0011] In an alternative embodiment, the mass content range of aluminum element in the sample to be measured is: 0.001 - 15%.

[0012] In an alternative embodiment, the mass content range of silicon element in the sample to be measured is: 1 - 15%;

[0013] In an alternative embodiment, the mass content range of aluminum element in the sample to be measured is: 1 - 15%;

[0014] In an alternative embodiment, the sampling amount of the sample to be measured is 0.2 - 0.25 g.

[0015] In an alternative embodiment, in the step (1), the sample to be measured includes materials containing aluminum element and silicon element;

[0016] In an alternative embodiment, in the step (1), the sample to be measured includes materials containing aluminum element;

[0017] In an alternative embodiment, in the step (1), the sample to be measured includes materials containing silicon element;

[0018] In an alternative embodiment, the sample to be measured includes at least one of iron-silicon sample, iron-silicon-aluminum sample, iron-silicon-chromium sample and iron-silicon-nickel sample;

[0019] Preferably, the iron-silicon sample includes at least one of iron-silicon magnetic powder core and iron-silicon magnetic powder;

[0020] Preferably, the iron-silicon-aluminum sample includes at least one of iron-silicon-aluminum magnetic powder core and iron-silicon-aluminum magnetic powder;

[0021] Preferably, the iron-silicon-chromium sample includes at least one of iron-silicon-chromium magnetic powder core and iron-silicon-chromium magnetic powder;

[0022] Preferably, the iron-silicon-nickel sample includes at least one of iron-silicon-nickel magnetic powder core and iron-silicon-nickel magnetic powder.

[0023] It should be noted here that the difference between magnetic powder core and magnetic powder is that the magnetic powder core is obtained by pressing magnetic powder after adding a coating agent.

[0024] In an alternative embodiment, in step (2), when preparing the standard solution, a high-purity iron test solution is further added; the addition of the high-purity iron test solution is to make the matrix composition of the standard solution more similar to that of the sample solution to be measured, reduce physical interference caused by matrix differences, and further improve the measurement accuracy of the present invention.

[0025] In an alternative embodiment, in step (2), the standard solution containing silicon elements with different concentrations further includes a high-purity iron test solution;

[0026] In an alternative embodiment, in step (2), the standard solution containing aluminum elements with different concentrations further includes a high-purity iron test solution;

[0027] Preferably, the purity of high-purity iron in the high-purity iron test solution is ≥99.98%;

[0028] Preferably, the mass ratio of high-purity iron in the sample to be measured and the high-purity iron test solution is (0.2 - 0.25):0.2.

[0029] In an alternative embodiment, in step (1), the sample to be measured is crushed and sieved;

[0030] Preferably, the mesh number of the sieving is 100 - 250 meshes.

[0031] In an alternative embodiment, in step (1), the heating temperature is 220 - 240 °C; at this heating temperature, part of the water in the acid solution will volatilize, but there is still enough volume of the acid solution to completely dissolve the sample to be measured; further, conventional methods in the art such as covering with a watch glass can be used to hinder the volatilization of water and improve the dissolution efficiency.

[0032] In an alternative embodiment, in step (1), the volume concentration of the sulfuric acid solution is 3 - 10 vol%; the solvent of the sulfuric acid solution includes water, and the solute sulfuric acid of the sulfuric acid solution is obtained through commercial channels or conventional methods in the art;

[0033] In an alternative embodiment, in step (1), the volume concentration of the phosphoric acid solution is 3 - 10 vol%; the solvent of the phosphoric acid solution includes water, and the solute phosphoric acid of the phosphoric acid solution is obtained through commercial channels or conventional methods in the art;

[0034] In an alternative embodiment, the solvent for the volume fixing step includes water.

[0035] In an alternative embodiment, in step (1), before collecting the dissolution solution, it further includes the steps of cooling to room temperature and adding ammonium fluoride. Adding ammonium fluoride can further dissolve the sample to be measured and improve the accuracy of the determination; when the dissolution is incomplete, ammonium fluoride needs to be added.

[0036] After adding ammonium fluoride to the dissolution solution, the same mass of ammonium fluoride also needs to be added to the blank solution.

[0037] In an alternative embodiment, in steps (2) and (3), the detection conditions include: the wavelength of silicon element is 251.611 nm or 212.412 nm;

[0038] In an alternative embodiment, the wavelength of Al element is 396.152 nm;

[0039] In an alternative embodiment, the high-frequency generator frequency is 1200 w, the auxiliary gas flow rate is 1.0 L / min, the nebulizer flow rate is 0.7 L / min, the plasma gas flow rate is 12 L / min, the number of repetitions is 3 times, the rinsing time is 30 s, and the integration time is 10 s.

[0040] The present invention also provides an application of the above method for determining the element content in an alloy based on inductively coupled plasma atomic emission spectrometry in the field of alloy material element detection or analysis.

[0041] The technical solution of the present invention has the following advantages:

[0042] 1. The method for determining the element content in an alloy provided by the present invention based on inductively coupled plasma atomic emission spectrometry includes the following steps: (1) Sample pretreatment: Mix the sample to be measured with an acid solution, heat until the sample is dissolved, collect the dissolution solution and make it up to a fixed volume to obtain a test solution; the acid solution includes at least one of sulfuric acid solution and phosphoric acid solution; (2) Prepare standard solutions containing silicon element and / or aluminum element with different concentrations, detect them by inductively coupled plasma atomic emission spectrometry analysis technology, obtain the spectral intensity of the standard solutions, and obtain the standard curve of the standard solution concentration and spectral intensity; (3) Detect the spectral intensity of the test solution, and calculate the content of silicon element and / or aluminum element in the test solution respectively according to the standard curve obtained in step (2). The determination method provided by the present invention can accurately detect the silicon content in existing iron-silicon materials and iron-silicon-aluminum materials. While being safe and simple to operate, it has a fast analysis speed, high precision, and good accuracy; using at least one of sulfuric acid solution and phosphoric acid solution to mix with the sample to be measured can completely dissolve the sample, and it is not easy to corrode the equipment, pollute the environment, or harm human health.

[0043] 2. The method for determining the element content in an alloy based on inductively coupled plasma atomic emission spectrometry provided by the present invention can simultaneously detect two elements by preparing a standard solution through one sample treatment, simplifies the determination procedure, and simplifies the defect of the prior art that generally uses the gravimetric method or colorimetric method to determine the silicon content in conventional iron-silicon materials. Description of the Drawings

[0044] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0045] Figure 1 is the silicon standard curve in Examples 1-2 of the present invention;

[0046] Figure 2 is the aluminum standard curve in Examples 1-2 of the present invention. Detailed Embodiments

[0047] The following embodiments are provided to better further understand the present invention, which is not limited to the best embodiment, and does not limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with those of other prior arts falls within the protection scope of the present invention.

[0048] For those steps or conditions not specified in the embodiments, the operations or conditions of the conventional experimental steps described in the literature in the art can be followed. For the reagents or instruments not specified for the manufacturer, they are all conventional reagent products that can be obtained through commercial purchase.

[0049] In the following embodiments of the present invention, unless otherwise specified, only reagents confirmed to be of analytical purity or higher purity (such as guaranteed reagent grade, electronic grade) are used in the analysis;

[0050] In the following embodiments of the present invention, for the standard storage solution: the single-element standard solution of Si uses a national certified reference material (or standard sample), and the standard solution contains 1000 μg of Si element per 1 mL; the single-element standard solution of Al uses a national certified reference material (or standard sample), and the standard solution contains 1000 μg of Al element per 1 mL.

[0051] The method for determining the silicon content and aluminum content in a test sample using an inductively coupled plasma atomic emission spectrometer according to the present invention, wherein the content ranges of the elements silicon and aluminum in the test sample are: 0.005% ≤ silicon ≤ 15%, 0.001% ≤ aluminum ≤ 15%; the specific steps are as follows:

[0052] (1) Sample pretreatment

[0053] Prepare sulfuric acid solution or phosphoric acid solution: Take commercially available concentrated sulfuric acid or concentrated phosphoric acid, and mix it with deionized water according to a volume ratio of (3 - 10):(90 - 97) to obtain sulfuric acid solution or phosphoric acid solution;

[0054] The sample to be tested is crushed and screened through a 100 - 250 mesh sieve; Weigh the sieved sample to be tested and place it in a polytetrafluoroethylene beaker, add deionized water, sulfuric acid solution and / or phosphoric acid solution, and heat and dissolve it at a low temperature of 220 - 240 °C until completely dissolved, then remove it to obtain the sample digestion solution (if there is still a small amount undissolved after the sample is dissolved at 220 - 240 °C for forty to fifty minutes, after the sample is cooled to room temperature, add ammonium fluoride, gently shake the beaker to dissolve the salts), transfer the sample digestion solution to a volumetric flask, and make up the volume to the scale with water (the fixed volume of the sample digestion solution is recorded as V), and shake well. Use a pipette to transfer the above - prepared solution to a volumetric flask, dilute it to the scale with water (the dilution factor of the sample is the ratio of the dilution volume to the transferred volume), and shake well to obtain the test solution.

[0055] Prepare the blank solution: Add deionized water, sulfuric acid solution and / or phosphoric acid solution to a polytetrafluoroethylene beaker, heat and dissolve it at a low temperature of 220 - 240 °C (if ammonium fluoride is added after the sample is cooled to room temperature, add the same mass of ammonium fluoride here after cooling to room temperature, gently shake the beaker to dissolve the salts), transfer it to a volumetric flask, make up the volume to the scale with water, and shake well. Use a pipette to transfer the above - prepared solution to a volumetric flask, dilute it to the scale with water, and shake well to obtain the blank solution.

[0056] (2) Prepare standard solutions

[0057] Weigh high - purity iron (GBW01402, purity ≥ 99.98%) into a beaker, add sulfuric acid solution and / or phosphoric acid solution, heat and dissolve it at a low temperature of 220 - 240 °C until clear, cool, transfer it to a volumetric flask, and dilute it to the scale with water, and shake well. This is the high - purity iron test solution. Respectively transfer the high - purity iron test solution to 5 volumetric flasks, and then use a pipette gun to add a standard stock solution containing the element to be measured (silicon element or aluminum element) to the volumetric flasks, dilute it to the scale with water, and shake well, and then transfer it to a clean plastic bottle for standby. Obtain standard solutions with increasing concentrations (the concentrations of the standard solutions are 0.00 μg / mL, 1.00 μg / mL, 2.00 μg / mL, 3.00 μg / mL, 4.00 μg / mL in sequence), which ensures the measurement accuracy and saves time at the same time;

[0058] (3) Instrument determination

[0059] Ignite the plasma torch of the inductively coupled plasma emission spectrometer and fully preheat and stabilize the instrument. Establish an applicable method. Select the element to be measured in the periodic table and choose the spectral line for testing in the spectral line library. Set the working parameters of the instrument as follows: high-frequency generator frequency 1200 w, auxiliary gas flow rate 1.0 L / min, nebulizer flow rate 0.7 L / min, plasma gas flow rate 12 L / min, number of repetitions 3 times, flushing time 30 s, integration time 10 s. Select the wavelengths of the elements to be measured: Si: 251.611 nm or 212.412 nm; Al: 396.152 nm;

[0060] Enter the control interface of the standard curve method. Aspirate the standard solution of the element to be measured in ascending order of concentration, and measure the emission spectral intensities of silicon and aluminum elements in each standard working solution. Take the concentrations of silicon and aluminum elements as the abscissa and the corresponding emission spectral intensities as the ordinate to plot the standard curve and ensure that the linear correlation coefficient of the curve is greater than 0.999.

[0061] Measure the emission spectral intensities of silicon and aluminum elements in the solution to be measured, and combine with the standard curve to obtain the contents of silicon and aluminum elements in the sample to be measured. The calculation formula for the content (wt%) is as follows:

[0062]

[0063] Wherein, X—the content of the element in the sample to be measured, unit wt%;

[0064] ρ—the mass concentration of the element to be measured in the sample solution, unit mg / L;

[0065] ρ0—the mass concentration of the element to be measured in the blank solution, unit mg / L;

[0066] V—the fixed volume of the sample digestion solution, unit mL;

[0067] F—the dilution factor of the sample;

[0068] m—the mass of the sample to be measured, unit g.

[0069] Using the above measurement method, the silicon content and / or aluminum content in iron-silicon samples, iron-silicon-aluminum samples, iron-silicon-chromium samples and iron-silicon-nickel samples can be measured quickly and accurately.

[0070] Example 1

[0071] This example provides a method for measuring the element content in an alloy based on inductively coupled plasma atomic emission spectrometry, including the following steps:

[0072] The sample to be measured in this example is an iron-silicon-aluminum magnetic powder core. The mass content of Si is measured to be 9.45% by chemical gravimetry, and the mass content of Al is determined to be 5.48% through the formula for preparing the magnetic powder core.

[0073] The iron-silicon-aluminum magnetic powder core is mechanically crushed and ground in a tungsten alloy container, and then sieved through a 100-250 mesh sieve. Then, 0.20 g to 0.25 g of the ground iron-silicon-aluminum magnetic powder core is weighed as the sample to be tested, accurate to 0.0001 g. Six portions of the sample to be tested are weighed for parallel determination, and a blank test is carried out together with the sample to be tested.

[0074] Prepare sulfuric acid solution: Mix commercially available concentrated sulfuric acid and deionized water in a volume ratio of 5:95 to obtain sulfuric acid solution.

[0075] Weigh the sample to be tested (accurate to 0.0001 g) into a 100 mL polytetrafluoroethylene beaker, add 20 mL of water and 20 mL of sulfuric acid solution, heat at low temperature (set the heating temperature at about 220 °C to keep the solution slightly boiling) to dissolve, remove it after complete dissolution, cool to room temperature, transfer the sample digestion solution to a 250 mL volumetric flask, and make up to the mark with water and shake well. Pipette 2.00 mL of the solution into a 100 mL volumetric flask, dilute to the mark with water and shake well.

[0076] Prepare blank solution: Add 20 mL of deionized water and 20 mL of sulfuric acid solution to a 100 mL polytetrafluoroethylene beaker, heat at low temperature for the same time as the sample to be tested (set the heating temperature at about 220 °C to keep the solution slightly boiling), transfer the solution to a 250 mL volumetric flask, make up to the mark with water and shake well. Pipette 2.00 mL of the solution into a volumetric flask, dilute to the mark with water and shake well to obtain the blank solution.

[0077] Weigh 0.2 g of high-purity iron (GBW01402, purity ≥ 99.98%) into a 200 mL beaker, add 20 mL of sulfuric acid solution, dissolve it at 220 °C until clear, cool, transfer it to a 250 mL volumetric flask, dilute to the mark with water and shake well. This is the high-purity iron test solution. Pipette 2.00 mL of the high-purity iron test solution into 5 100 mL volumetric flasks respectively, and then pipette 0.00 μL, 100 μL, 200 μL, 300 μL, 400 μL of silicon standard solution and 0.00 μL, 100 μL, 200 μL, 300 μL, 400 μL of aluminum standard solution into the 100 mL volumetric flasks respectively, dilute to the mark with water and shake well, and then transfer them to clean plastic bottles for standby. The silicon and aluminum concentrations in the mixed standard solution are shown in Table 1.

[0078] Table 1 Solution concentrations of silicon and aluminum elements in the standard solution

[0079] Serial number of calibration series solutions 1 2 3 4 5 Concentration of silicon standard solution μg / mL 0.00 1.00 2.00 3.00 4.00 Concentration of aluminum standard solution μg / mL 0.00 1.00 2.00 3.00 4.00

[0080] Ignite the plasma torch of the inductively coupled plasma emission spectrometer and fully preheat to stabilize the instrument. Establish a measurement method, select the elements to be measured Si and Al, and the wavelength positions are Si: 251.611 nm; Al: 396.152 nm. Set the high-frequency generator frequency of the instrument to 1200 w, the auxiliary gas flow rate to 1.0 L / min, the nebulizer flow rate to 0.7 L / min, the plasma gas flow rate to 12 L / min, the number of repetitions to 3 times, the rinsing time to 30 s, and the integration time to 10 s. Input the curve mass concentrations of silicon and aluminum, which are 0.00 μg / mL, 1.00 μg / mL, 2.00 μg / mL, 3.00 μg / mL, and 4.00 μg / mL respectively.

[0081] Taking the concentration of the silicon standard solution as the abscissa and the intensity response value of the analysis spectral line on the instrument as the ordinate, draw a standard working curve. The linear coefficient is required to be above 0.999 to determine the content of the sample solution. In this embodiment, the formed silicon standard curve is shown in Figure 1 , and the formed aluminum standard curve is shown in Figure 2 .

[0082] Measure in parallel 6 times according to the above method, and calculate the silicon content and aluminum content respectively according to formula (1). The results are shown in Table 2,

[0083]

[0084] where X is the content of the element in the sample to be measured, in wt%;

[0085] ρ is the mass concentration of the element to be measured in the sample solution, in mg / L;

[0086] ρ0 is the mass concentration of the element to be measured in the blank solution, in mg / L;

[0087] V is the fixed volume of the sample digestion solution, in mL;

[0088] F is the dilution factor of the sample;

[0089] m is the mass of the sample to be measured taken, in g.

[0090] Table 2 Parallel test results of silicon and aluminum

[0091]

[0092]

[0093] According to Table 2, it can be seen that in this embodiment, the measured value of Si in the iron-silicon-aluminum magnetic powder core sample is 9.41%, and the measured value of Al is 5.43%, which is consistent with the actual silicon and aluminum contents in the sample, proving the high accuracy of the method of this application.

[0094] Example 2

[0095] This embodiment provides a method for determining the element content in an alloy by inductively coupled plasma atomic emission spectrometry, comprising the following steps:

[0096] In this embodiment, the sample to be measured is ferrosilicon alloy powder, and the mass content of Si in it is measured to be 6.53% by chemical gravimetric method.

[0097] Weigh 0.25 g of ferrosilicon alloy powder as the sample to be measured, accurate to 0.0001 g. At the same time, weigh six portions of 0.25 g of the sample to be measured for parallel determination, accurate to 0.0001 g. Conduct a blank test along with the sample to be measured.

[0098] Prepare phosphoric acid solution: Mix commercially available concentrated phosphoric acid and deionized water in a volume ratio of 5:95 to obtain phosphoric acid solution;

[0099] Place the sample to be measured (accurate to 0.0001 g) in a 100 mL polytetrafluoroethylene beaker, add 20 mL of water and 20 mL of phosphoric acid solution, heat at low temperature (set the heating temperature at about 220 °C to keep the solution slightly boiling) until completely dissolved, then remove and cool to room temperature. Transfer the sample digestion solution to a 250 mL volumetric flask, dilute to the mark with water, and shake well. Pipette 2.00 mL of the solution into a 100 mL volumetric flask, dilute to the mark with water, and shake well.

[0100] Prepare blank solution: Add 20 mL of deionized water and 20 mL of phosphoric acid solution to a 100 mL polytetrafluoroethylene beaker, heat at low temperature for the same time as the sample to be measured (set the heating temperature at about 220 °C to keep the solution slightly boiling), transfer the solution to a 250 mL volumetric flask, dilute to the mark with water, and shake well. Pipette 2.00 mL of the solution into a volumetric flask, dilute to the mark with water, and shake well to obtain the blank solution.

[0101] Weigh 0.2 g of high-purity iron (GBW01402, purity ≥ 99.98%) into a 200 mL beaker, add 20 mL of phosphoric acid solution, dissolve at 220 °C until clear, cool, transfer to a 250 mL volumetric flask, dilute to the mark with water, and shake well. This is the high-purity iron test solution. Pipette 2.00 mL of the high-purity iron test solution into 5 100 mL volumetric flasks respectively, and then use a pipette gun to pipette 0.00 μL, 100 μL, 200 μL, 300 μL, 400 μL of silicon standard solution into 100 mL volumetric flasks, dilute to the mark with water, and shake well. Then transfer to a clean plastic bottle for standby. The silicon concentration in the standard solution is shown in Table 3.

[0102] Table 3 Solution concentration of silicon element in the standard solution

[0103] Serial number of calibration series solutions 1 2 3 4 5 Concentration in silicon solution μg / mL 0.00 1.00 2.00 3.00 4.00

[0104] Ignite the plasma torch of the inductively coupled plasma emission spectrometer and fully preheat to stabilize the instrument. Establish a measurement method, select the element Si to be measured, and the wavelength position is Si: 251.611 nm; set the high-frequency generator frequency of the instrument to 1200 w, the auxiliary gas flow rate to 1.0 L / min, the nebulizer flow rate to 0.7 L / min, the plasma gas flow rate to 12 L / min, the number of repetitions to 3 times, the flushing time to 30 s, and the integration time to 10 s; respectively input the mass concentrations of the silicon standard solutions of 0.00 μg / mL, 1.00 μg / mL, 2.00 μg / mL, 3.00 μg / mL, and 4.00 μg / mL.

[0105] Taking the concentration of the silicon standard solution as the abscissa and the intensity response value of the analysis spectral line on the instrument as the ordinate, plot the standard working curve to quantify the sample. In this embodiment, the formed silicon standard curve is shown in Figure 1 and the formed aluminum standard curve is shown in Figure 2 as shown.

[0106] Parallel determination is carried out 6 times according to the above method, and the silicon content is calculated according to formula (1). The results are shown in Table 3.

[0107]

[0108] Among them, X—the content of the element in the sample to be measured, unit: wt%;

[0109] ρ—the mass concentration of the element to be measured in the sample solution, unit: mg / L;

[0110] ρ0—the mass concentration of the element to be measured in the blank solution, unit: mg / L;

[0111] V—the fixed volume of the sample digestion solution, unit: mL;

[0112] F—the dilution factor of the sample;

[0113] m—the mass of the sample to be measured taken, unit: g.

[0114] Table 3 Parallel test results of silicon

[0115] Serial number Sample weight taken g Silicon content % 1 0.2562 6.58 2 0.2510 6.60 3 0.2544 6.57 4 0.2521 6.55 5 0.2580 6.62 6 0.2539 6.56 Average value of results % 6.58 Relative standard deviation RSD % 0.33

[0116] According to Table 3, it can be seen that the measured value of Si in the iron-silicon alloy powder sample in this embodiment is 6.58%, which is consistent with the actual silicon content in the sample, proving that the method of this application has high accuracy.

[0117] Comparative Example 1

[0118] This comparative example provides a method for determining the element content in an alloy based on inductively coupled plasma atomic emission spectrometry. Compared with Example 1, the only difference is that 20 mL of concentrated hydrochloric acid (37 wt%) is used instead of 20 mL of sulfuric acid solution in Example 1.

[0119] After adding the concentrated hydrochloric acid, the reaction was intense, and white colloidal substances appeared on the inner wall of the beaker. After the reaction ended, the solution was filtered through a fast filter paper into a volumetric flask.

[0120] The silicon content and aluminum content were calculated according to Equation (1), and the results are shown in Table 4.

[0121] Table 4 Parallel test results of silicon and aluminum

[0122]

[0123]

[0124] As can be seen from Table 4, the measured value of Si in the iron-silicon-aluminum magnetic powder core sample in this example is only 4.73%, which does not match the actual silicon content in the sample, and the data repeatability of each parallel sample is poor, proving that the solution directly dissolved with concentrated hydrochloric acid is not suitable for this method.

[0125] Obviously, the above examples are only for clear illustration and not for limiting the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A method for determining the element content in an alloy based on inductively coupled plasma atomic emission spectrometry, characterized in that, It includes the following steps: (1) Sample pretreatment: Mix the sample to be tested with an acid solution, heat it until the sample dissolves, collect the dissolved solution and make it up to a constant volume to obtain a test solution; the acid solution includes at least one of a sulfuric acid solution and a phosphoric acid solution; (2) Prepare standard solutions containing silicon element and / or aluminum element with different concentrations, detect them by inductively coupled plasma atomic emission spectrometry analysis technology, obtain the spectral intensities of the standard solutions, and obtain the standard curve of the standard solution concentration and spectral intensity; (3) Detect the spectral intensity of the test solution, and calculate the contents of silicon element and / or aluminum element in the test solution respectively according to the standard curve obtained in step (2).

2. The method for determining the element content in an alloy based on the inductively coupled plasma atomic emission spectrometry according to claim 1, characterized in that, The mass content range of silicon element in the sample to be tested is: 0.005 - 15%; and / or, The mass content range of aluminum element in the sample to be tested is: 0.001 - 15%.

3. The method for determining the element content in an alloy based on the inductively coupled plasma atomic emission spectrometry according to claim 2, wherein The mass content range of silicon element in the sample to be tested is: 1 - 15%; and / or, The mass content range of aluminum element in the sample to be tested is: 1 - 15%; and / or, The sampling amount of the sample to be tested is 0.2 - 0.25 g.

4. The method for determining the element content in an alloy based on the inductively coupled plasma atomic emission spectrometry according to any one of claims 1-3, characterized in that, In step (1), the sample to be tested includes materials containing aluminum element and / or silicon element; Preferably, the sample to be tested includes at least one of iron-silicon samples, iron-silicon-aluminum samples, iron-silicon-chromium samples and iron-silicon-nickel samples; Preferably, the iron-silicon sample includes at least one of iron-silicon magnetic powder cores and iron-silicon magnetic powders; Preferably, the iron-silicon-aluminum sample includes at least one of iron-silicon-aluminum magnetic powder cores and iron-silicon-aluminum magnetic powders; Preferably, the iron-silicon-chromium sample includes at least one of iron-silicon-chromium magnetic powder cores and iron-silicon-chromium magnetic powders; Preferably, the iron-silicon-nickel sample includes at least one of iron-silicon-nickel magnetic powder cores and iron-silicon-nickel magnetic powders.

5. The method for determining the element content in an alloy based on the inductively coupled plasma atomic emission spectrometry according to any one of claims 1-4, characterized in that In step (2), when preparing the standard solution, it also includes adding a high-purity iron test solution; Preferably, the purity of high-purity iron in the high-purity iron test solution is ≥99.98%; Preferably, the mass ratio of high-purity iron in the sample to be tested and the high-purity iron test solution is (0.2 - 0.25):0.

2.

6. The method for determining the element content in an alloy based on the inductively coupled plasma atomic emission spectrometry according to any one of claims 1-5, characterized in that, In step (1), the sample to be tested is crushed and sieved; Preferably, the mesh number of the sieving is 100 - 250 meshes.

7. The method for determining the element content in an alloy based on the inductively coupled plasma atomic emission spectrometry according to any one of claims 1-6, characterized in that, In step (1), the heating temperature is 220 - 240°C; and / or, In step (1), the volume concentration of the sulfuric acid solution is 3 - 10 vol%; and / or, In step (1), the volume concentration of the phosphoric acid solution is 3 - 10 vol%; and / or, The solvent for the constant volume step includes water.

8. The method for determining the element content in an alloy based on the inductively coupled plasma atomic emission spectrometry according to any one of claims 1-7, characterized in that, In step (1), before collecting the dissolved solution, it also includes the steps of cooling to room temperature and adding ammonium fluoride.

9. The method for determining the element content in an alloy based on the inductively coupled plasma atomic emission spectrometry according to any one of claims 1-8, characterized in that, In steps (2) and (3), the detection conditions include: the wavelength of silicon element is 251.611 nm or 212.412 nm; and / or, The wavelength of Al element is 396.152 nm; and / or, The high-frequency generator frequency is 1200 w, the auxiliary gas flow rate is 1.0 L / min, the nebulizer flow rate is 0.7 L / min, the plasma gas flow rate is 12 L / min, the number of repetitions is 3 times, the rinsing time is 30 s, and the integration time is 10 s.

10. Use of the method for determining the element content in an alloy based on inductively coupled plasma atomic emission spectrometry according to any one of claims 1-9 in the field of alloy material element detection or analysis.

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