ICP (Inductively Coupled Plasma) detection method for contents of aluminum, calcium and zirconium elements in silicon-zirconium alloy

Abstract

The invention discloses an ICP (Inductively Coupled Plasma) detection method for the contents of aluminum, calcium and zirconium elements in silicon-zirconium alloy, and belongs to the technical field of chemical detection analysis, and the ICP detection method comprises the following steps: preparing a sample with the concentration of 2mg / mL, and selecting the three elements of aluminum, calcium and zirconium with the analysis wavelengths of 308.215 nm, 183.801 nm and 327.305 nm in sequence; preparing a zirconium standard solution with the concentration of 1 mg / mL; a series of silicon iron standard samples are selected to be dissolved, 0.50 mL, 1.00 mL, 2.00 mL, 3.00 mL and 5.00 mL of zirconium standard solutions are added before volume metering, and then volume metering is conducted; measuring the emission intensity of aluminum, calcium and zirconium elements in the zirconium standard solution series, and drawing a standard working curve by taking the mass concentration of the aluminum, calcium and zirconium elements as a horizontal coordinate and the emission intensity as a vertical coordinate; and detecting the sample solution, and calculating the contents of aluminum, calcium and zirconium in the sample according to the working curve.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical detection and analysis, and in particular relates to an inductively coupled plasma emission spectroscopy (ICP) detection method for the contents of aluminum, calcium and zirconium in a silicon-zirconium alloy. Background Art

[0002] Zirconium is a rare metal. During the steelmaking process, zirconium acts as a deoxidizing, denitrifying, and desulfurizing element, refining the austenite grains and preventing hot brittleness. In cast iron, zirconium facilitates graphitization of white cast iron and shortens the annealing time of ductile cast iron. Silicon-zirconium alloys are widely used in metallurgy, foundry, and other industries. Their main components are: W (Si) = 72% to 80%, W (Zr) = 1.5% to 2.5%, W (Ca) = 1.5% to 2.5%, W (Al) ≤ 1.5%, with the balance being Fe. Silicon-zirconium alloys are used as deoxidizers and alloying additives in special-purpose high-temperature alloys, low-alloy high-strength steels, ultra-high-strength steels, and cast iron. These alloys are then used in atomic energy, aviation, and radio technology.

[0003] While there have been reports analyzing trace element content in silicon-zirconium alloys, these reports involved a single sample dissolution, only determining some of the three trace elements: aluminum, calcium, and zirconium. There is no analytical method for the simultaneous determination of these three elements in silicon-zirconium alloys. Inductively coupled plasma atomic emission spectrometry (ICP-AES) has been widely used in various fields in recent years due to its low detection limit, fast analysis speed, high sensitivity, minimal inter-element interference, and ability to simultaneously detect multiple elements.

[0004] Existing reports use ICP-AES to test silicon-zirconium alloys, such as patent CN104597037A, which describes a method for determining zirconium content in silicon-zirconium alloys. However, these methods typically focus on single elements. For example, if aluminum, calcium, and zirconium are to be measured, different standard solutions must be used to create a calibration curve, and at least two tests must be performed to determine the contents of all three elements. This method is cumbersome. Summary of the Invention

[0005] The present invention aims to provide an inductively coupled plasma atomic emission spectrometry (ICP-AES) method for simultaneously determining aluminum, calcium and zirconium in a silicon-zirconium alloy.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] An ICP detection method for the content of aluminum, calcium, and zirconium in a silicon-zirconium alloy comprises the following steps:

[0008] Step S1, preparing a sample, making the sample into powder, sieving, weighing a silicon-zirconium alloy sample in a platinum dish, adding nitric acid and hydrofluoric acid to dissolve, adding perchloric acid and heating until viscous, cooling, adding hydrochloric acid and heating to dissolve, cooling and transferring to a volumetric flask, making up to volume with pure water, mixing and filtering, and setting aside;

[0009] Step S2: Select 2-3 spectral lines for each element to be measured. The analytical wavelengths for aluminum, calcium, and zirconium are selected as follows: 308.215nm, 183.801nm, and 327.305nm, respectively. The ICP-AES method can simultaneously select multiple characteristic spectral lines for the determination of each element and has a synchronous background correction function. Therefore, in the experiment, 2-3 spectral lines are selected for each element to be measured. The intensity, interference, and stability are comprehensively analyzed to select the analytical line with high emission intensity and low spectral line interference. The analytical wavelengths for aluminum, calcium, and zirconium selected in the experiment are: 308.215nm, 183.801nm, and 327.305nm, respectively.

[0010] Step S3, zirconium standard solution: weigh zirconium oxychloride and place it in a beaker, add hydrochloric acid, heat to dissolve, cool and transfer to a volumetric flask, add hydrochloric acid and dilute to the mark with water, and mix well;

[0011] Step S4: Select a series of ferrosilicon standard samples and dissolve them according to step S1. Before constant volume, add 0.50 mL, 1.00 mL, 2.00 mL, 3.00 mL, and 5.00 mL of zirconium standard solution respectively;

[0012] Step S5, turning on the inductively coupled plasma optical emission spectrometer, setting the parameters of the inductively coupled plasma optical emission spectrometer, and stabilizing it; measuring the emission intensity of aluminum, calcium, and zirconium elements in the zirconium standard solution series, and plotting a standard working curve with the mass concentration of aluminum, calcium, and zirconium elements as the abscissa and the emission intensity as the ordinate;

[0013] Step S6: Detection: The sample solution in step S1 is tested, and the contents of aluminum, calcium, and zirconium in the sample are calculated according to the working curve.

[0014] The further improvement of the technical solution of the present invention is that the parameter settings of the inductively coupled plasma emission spectrometer are as follows: RF power: 1150 W, flushing pump speed: 100 rpm, analysis pump speed: 50 rpm, nebulization chamber pressure: 30 psi, nebulizing gas flow rate: 0.7 L / min, auxiliary gas flow rate: 0.5 L / min, flushing time: 30 s, integration time: short wave 15 s, long wave 5 s.

[0015] A further improvement of the technical solution of the present invention is that in step S1, the silicon-zirconium alloy sample is passed through a 0.088 mm sieve.

[0016] A further improvement of the technical solution of the present invention is that: in step S1, the concentration of the sample solution is 2 mg / mL, 10 mL of nitric acid is added, 5 mL of hydrofluoric acid is added dropwise, and after the reaction slows down, 5 mL of perchloric acid is added, and 10 mL of hydrochloric acid solution is added, wherein the volume fraction of the hydrochloric acid solution is 50%.

[0017] A further improvement of the technical solution of the present invention is that the concentration of Zr in the Zr standard solution prepared in step S3 is 1 mg / mL.

[0018] A further improvement of the technical solution of the present invention is that when preparing the standard solution in step S3, 6 mol / L of hydrochloric acid is used to dissolve zirconium oxychloride, the volume mass ratio of the added hydrochloric acid to Zr is 50 mL / mg, and the hydrochloric acid added after transferring to the volumetric flask is hydrochloric acid with a volume fraction of 5%.

[0019] Due to the adoption of the above technical solution, the technical advancements achieved by the present invention are:

[0020] The detection method of the present invention uses an inductively coupled plasma spectrometer to simultaneously establish working curves for aluminum, calcium and zirconium elements in one detection program, thereby solving the problem that the contents of aluminum, calcium and zirconium elements in silicon-zirconium alloys cannot be detected simultaneously.

[0021] The method of the present application has a fast detection speed, accurate data, simple operation, small amount of chemical reagents, short detection time, low detection cost and is more environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is the Al (308.215 nm) working curve of Example 1;

[0023] Figure 2 is the Ca (183.801 nm) working curve of Example 1;

[0024] Figure 3 This is the Zr (327.305 nm) working curve of Example 1. DETAILED DESCRIPTION

[0025] The present invention is described in further detail below in conjunction with the embodiments:

[0026] Example 1

[0027] 1. Turn on the computer

[0028] Ambient temperature 20-25 degrees Celsius; humidity 20%-80%; liquid argon purity ≥99.996%.

[0029] Parameter settings: RF power: 1150 W, flushing pump speed: 100 rpm, analysis pump speed: 50 rpm, nebulization chamber pressure: 30 psi, nebulizing gas flow rate: 0.7 L / min, auxiliary gas flow rate: 0.5 L / min, flushing time: 30 s, integration time: short wave 15 s, long wave 5 s.

[0030] The machine is stable for more than 0.5 hours after startup.

[0031] Ambient temperature 20-25 degrees Celsius; humidity 20%-80%; liquid argon purity ≥99.996%.

[0032] 2. Sample dissolution:

[0033] Accurately weigh 0.1000g of sample in 50mL of platinum blood, add 10mL of nitric acid, and dropwise add 5mL of hydrofluoric acid to dissolve the sample. After the reaction slows down, add 5mL of perchloric acid and heat on a hot plate. Evaporate and smoke until it becomes viscous. Remove and cool. Add 10mL of hydrochloric acid with a volume fraction of (1+1) and heat to dissolve the salts. Remove and cool to room temperature. Transfer the solution into a 50mL volumetric flask, dilute to the scale with water, shake well and filter, and measure under the working conditions of the instrument.

[0034] Reagents: Use analytically pure or superior grade reagents and laboratory water that complies with the requirements of GB / T6682.

[0035] Sample particle size: Samples shall be taken and prepared in accordance with the provisions of GB / T 4010. Silicon-zirconium alloy samples shall pass through a 0.088mm sieve.

[0036] 3. Select elemental analysis lines: 2-3 spectral lines were selected for each element to be measured. The analytical wavelengths for aluminum, calcium, and zirconium were 308.215nm, 183.801nm, and 327.305nm, respectively. The ICP-AES method can simultaneously select multiple characteristic spectral lines for each element and has a synchronous background correction function. Therefore, 2-3 spectral lines were selected for each element in the experiment. A comprehensive analysis of intensity, interference, and stability was performed to select analytical lines with high emission intensity and minimal spectral interference. The analytical wavelengths for aluminum, calcium, and zirconium were 308.215nm, 183.801nm, and 327.305nm, respectively. This was based on the fact that Si accounts for the largest proportion in the standard substance and sample, and wavelengths with significant Si interference needed to be eliminated. Fe also accounts for a relatively large proportion. Based on this, wavelengths with significant Fe interference were eliminated. Comprehensive analysis revealed the optimal analytical wavelengths for aluminum, calcium, and zirconium.

[0037] 4. Prepare standard solution:

[0038] Zirconium standard solution: 1 mg / mL. Weigh 3.5412 g zirconium oxychloride (ZrOCl2·8H2O mass fraction greater than 99.99%) and place it in a 250 mL polytetrafluoroethylene beaker. Add 50 mL of 6 mol / L hydrochloric acid and heat to dissolve. After cooling, transfer to a 1000 mL plastic volumetric flask, add 50 mL of 5% hydrochloric acid (volume fraction), dilute to the mark with water, and mix thoroughly.

[0039] 5. Working curve and detection limit

[0040] A series of ferrosilicon standard samples were selected and dissolved according to the experimental method. The content ranges of Al and Ca in the ferrosilicon standard samples are shown in Table 1. The Al content range is 0.24-2.45%, and the Ca content range is 0.064-2.47%. (The ferrosilicon standard samples are purchasable samples, in which the element content is indicated.) At least 5 ferrosilicon standard samples were selected and dissolved according to the above sample dissolution method. Before constant volume, 0.50mL, 1.00mL, 2.00mL, 3.00mL, and 5.00mL of zirconium standard solution were added respectively. After constant volume, the emission intensity of aluminum, calcium, and zirconium elements in the standard solution series was measured. The detection wavelengths were 308.215nm, 183.801nm, and 327.305nm. The mass concentrations of aluminum, calcium, and zirconium elements were used as the horizontal coordinates, and the emission intensity was used as the vertical coordinates to draw the standard working curves of aluminum, calcium, and zirconium elements (see Figure 1 、 Figure 2 、 Figure 3 ), the linear range and correlation coefficient of the standard curve are shown in Table 1. Under the same conditions, the blank solution was measured 11 times continuously, and the concentration corresponding to 10 times the standard deviation of the blank signal measurement value was taken as the element detection limit. The results are shown in Table 1.

[0041] Table 1 Linear parameters and detection limits (n=11)

[0042]

[0043] 6. Testing:

[0044] After the working curve is drawn, the sample to be tested is immediately tested on the working curve, and the value calculated by the working curve is the content of aluminum, calcium and zirconium elements.

[0045] 7. Precision and accuracy of the detection method:

[0046] Two national standard ferrosilicon samples and one silicon zirconium sample were selected and tested 10 times in parallel. The results are shown in Table 2.

[0047] Table 2 Precision analysis results (n=10)

[0048]

[0049]

[0050] 8. Recovery rate test:

[0051] To verify the accuracy of the method, a spike recovery test was conducted by adding different zirconium standard solutions to a silicon-zirconium alloy sample according to the test method and selected working conditions. The results are shown in Table 3. As can be seen from the data in Table 3, the spike recovery ranged from 100.0% to 104.0%.

[0052] Table 3 Recovery analysis results (n=10)

[0053]

[0054] Through a series of experimental studies, this paper established an ICP-AES determination method for aluminum, calcium and zirconium in silicon-zirconium alloy. This method is fast and simple, and the measurement results are relatively satisfactory, which can meet the requirements of production analysis.

Claims

1. An ICP detection method for the content of aluminum, calcium and zirconium in silicon-zirconium alloy, characterized in that The following steps are involved: Step S1, preparing a sample, making the sample into powder, sieving, weighing a silicon-zirconium alloy sample in a platinum dish, adding nitric acid and hydrofluoric acid to dissolve, adding perchloric acid and heating until viscous, cooling, adding hydrochloric acid and heating to dissolve, cooling and transferring to a volumetric flask, making up to volume with pure water, mixing and filtering, and setting aside; Step S2: Select 2-3 spectral lines for each element to be measured, and the analysis wavelengths of aluminum, calcium, and zirconium are selected as follows: 308.215nm, 183.801nm, and 327.305nm; Step S3, zirconium standard solution: weigh zirconium oxychloride and place it in a beaker, add hydrochloric acid, heat to dissolve, cool, transfer to a volumetric flask, add hydrochloric acid and dilute to the mark with water, and mix well; Step S4: Select a series of ferrosilicon standard samples and dissolve them according to step S1. Before constant volume, add 0.50 mL, 1.00 mL, 2.00 mL, 3.00 mL, and 5.00 mL of zirconium standard solution, respectively, and then constant volume; Step S5: turning on the inductively coupled plasma optical emission spectrometer, setting the parameters of the inductively coupled plasma optical emission spectrometer, and stabilizing the instrument; Determine the emission intensity of aluminum, calcium, and zirconium elements in the zirconium standard solution series, and draw a standard working curve with the mass concentration of aluminum, calcium, and zirconium elements as the abscissa and the emission intensity as the ordinate; Step S6: Detection: The sample solution in step S1 is tested, and the contents of aluminum, calcium, and zirconium in the sample are calculated according to the working curve.

2. The ICP detection method for the content of aluminum, calcium and zirconium in a silicon-zirconium alloy according to claim 1, characterized in that: The parameter settings of the inductively coupled plasma optical emission spectrometer were as follows: RF power: 1150 W, flushing pump speed: 100 rpm, analysis pump speed: 50 rpm, nebulization chamber pressure: 30 psi, nebulizing gas flow rate: 0.7 L / min, auxiliary gas flow rate: 0.5 L / min, flushing time: 30 s, integration time: short wave 15 s, long wave 5 s.

3. The ICP detection method for the content of aluminum, calcium and zirconium in a silicon-zirconium alloy according to claim 1, characterized in that: In step S1, the silicon-zirconium alloy sample is passed through a 0.088 mm sieve.

4. The ICP detection method for the content of aluminum, calcium and zirconium in a silicon-zirconium alloy according to claim 1, characterized in that: In step S1, the concentration of the sample solution is 2 mg / mL, 10 mL of nitric acid is added, 5 mL of hydrofluoric acid is added dropwise, and after the reaction slows down, 5 mL of perchloric acid is added, and 10 mL of hydrochloric acid solution is added, where the volume fraction of the hydrochloric acid solution is 50%.

5. The ICP detection method for the content of aluminum, calcium and zirconium in a silicon-zirconium alloy according to claim 1, characterized in that: The Zr concentration in the Zr standard solution prepared in step S3 is 1 mg / mL.

6. The ICP detection method for the content of aluminum, calcium and zirconium in a silicon-zirconium alloy according to claim 1, characterized in that: When preparing the standard solution in step S3, 6 mol / L of hydrochloric acid is used to dissolve zirconium oxychloride, the volume mass ratio of the added hydrochloric acid to Zr is 50 mL / mg, and the hydrochloric acid added after transferring to the volumetric flask is 5% by volume hydrochloric acid.

7. The ICP detection method for the content of aluminum, calcium and zirconium in a silicon-zirconium alloy according to claim 1, characterized in that: In step S4, the Al content range of the ferrosilicon standard samples is 0.24-2.45%, and the Ca content range is 0.064-2.47%. At least five ferrosilicon standard samples are selected.

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