Method for testing impurity element content of primary magnesium ingot by ICP (Inductively Coupled Plasma) spectrometry

Abstract

The invention relates to the field of test and analysis of impurity element content of primary magnesium ingots, in particular to a method for testing impurity element content of primary magnesium ingots by ICP (inductively coupled plasma) spectrometry, which comprises the following steps: firstly adding H2O2 into a magnesium ingot sample to infiltrate the sample, then adding HCl at an interval of less than 1 minute to carry out first reaction, carrying out first heating after the reaction is finished, and then carrying out second heating, cooling to 20-30 DEG C, transferring to a volumetric flask, and fixing the volume by using third-level water to obtain a sample solution; establishing a working curve by using an ICP spectrometer and a standard solution; testing the sample solution; the ratio of the mass of the magnesium ingot sample to the volume of H2O2 to the volume of HCl is 1: (3-10): (30-54), the method fills the standard vacancy of ICP spectrometry analysis of the silicon element in the primary magnesium ingot, a reliable basis is provided for chemical component analysis of the primary magnesium ingot, the test result is surface, and the method for testing the mass fraction of the impurity elements in the primary magnesium ingot provided by the invention has the advantages of high analysis precision, simple operation, high accuracy and high reliability. The analysis period is short, and related chemical varieties are few.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of testing and analyzing the impurity element content of raw magnesium ingot, in particular to a method for testing the impurity element content of raw magnesium ingot by ICP spectrometry. BACKGROUND

[0002] At present, the testing and analyzing of the impurity element content of raw magnesium ingot usually adopts direct-reading spectrometry, X-ray fluorescence spectrometry, chemical method and ICP spectrometry.

[0003] The direct-reading spectrometry and X-ray fluorescence spectrometry are poor in representativeness, especially for the sample with uneven composition; the chemical method can only test single element, is time-consuming, and uses many types of chemical reagents, which is harmful to human health; and the ICP spectrometry method without silicon element analysis method is provided in the existing standard GB / T13748.20.

[0004] Therefore, it is urgent to provide a method for testing the impurity element content of raw magnesium ingot by ICP spectrometry, to solve the content analysis of silicon element in raw magnesium ingot, reduce the use of chemical reagents, and improve the analysis accuracy and representativeness. SUMMARY

[0005] The present application aims to solve the technical problem of providing a method for testing the impurity element content of raw magnesium ingot by ICP spectrometry.

[0006] In order to achieve the above-mentioned purpose, the present application provides a method for testing the impurity element content of raw magnesium ingot by ICP spectrometry, wherein the method comprises:

[0007] S1, removing the surface oil stains and oxide film of the raw magnesium ingot, obtaining continuous chips by mechanical processing, and mixing the continuous chips;

[0008] S2, taking a magnesium ingot sample from the continuous chips, first adding H2O2 to soak the sample, then adding dilute HCl to perform a first reaction with an interval of less than 1 minute, performing a first heating after the reaction is completed, performing a second heating, cooling to 20-30℃, transferring to a volumetric flask and using tertiary water to constant volume to obtain a sample solution;

[0009] S3, first adding H2O2 to soak the sample, then adding dilute HCl to perform a second reaction with an interval of less than 1 minute, performing a third heating after the reaction is completed, performing a fourth heating, cooling to 20-30℃, transferring to a volumetric flask and using tertiary water to constant volume to obtain a magnesium matrix solution;

[0010] S4, using the magnesium matrix solution of S3 to prepare standard solutions of Si, Al, Mn, Fe, Cu and Ni;

[0011] S5, using ICP spectrometer and standard solution in S4 to establish working curve;

[0012] S6, testing sample solution obtained in S2;

[0013] In S2, the ratio of the mass of the magnesium ingot sample, the volume of H2O2 and the volume of HCl is 1:3-10:30-54.

[0014] The beneficial effects of the present application are:

[0015] The present application adopts a specific pretreatment method of hydrogen peroxide and hydrochloric acid and a matrix matching method to prepare a working curve, and the content of impurity elements in the magnesium ingot can be tested simultaneously by the standard curve method of the ICP spectrometer. The analysis precision is high, the analysis period is short, the types of chemical drugs involved are few, and the upper limit of the analysis range of each element can reach Si: 0.06%, Al: 0.06%, Mn: 0.06%, Fe: 0.06%, Cu: 0.03%, and Ni: 0.01%. DETAILED DESCRIPTION

[0016] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and any values are understood to be approximate values. The endpoints of the ranges of values and the values of individual points are not to be construed as limiting the maximum or minimum values which can be obtained. The endpoints of the ranges of values will provide better guidance for a person of ordinary skill in the art when the ranges are expressly defined.

[0017] In the present application, the primary magnesium ingot refers to a magnesium ingot with high purity produced by using ore as raw material, which meets the national standard GB / T3499 and is commonly used for manufacturing high-end magnesium alloy, aerospace materials and magnesium element additive materials in other metal casting processes.

[0018] In the prior art, the test and analysis of the content of impurity elements in the primary magnesium ingot usually adopts direct reading spectrometry, X-ray fluorescence spectrometry, chemical method and ICP spectrometry. The direct reading spectrometry and the X-ray fluorescence spectrometry have poor representativeness, especially for samples with uneven composition. The chemical method can only test single elements, is time-consuming, uses many types of chemical preparations and causes great harm to personal health. The ICP spectrometry has no silicon element analysis method.

[0019] In the present application, the inventors find that the content of impurity silicon elements in the primary magnesium ingot can be determined by using ICP spectrometry if a specific solvent and dosage are used.

[0020] To achieve this goal, the inventors try to optimize the dosage and adding method of the solvent, and find that the above-mentioned goal can be achieved by using a specific dosage and adding method of the solvent.

[0021] The first aspect of the present application provides a method for testing the impurity element content of native magnesium ingot by ICP spectrometry, wherein the method comprises:

[0022] S1, removing the surface oil stains and oxide film of the native magnesium ingot, obtaining continuous chips by mechanical processing, and mixing the continuous chips;

[0023] S2, taking a magnesium ingot sample from the continuous chips, first adding H2O2 to soak the sample, then adding dilute HCl to perform a first reaction with an interval of less than 1 minute, performing a first heating after the reaction is completed, performing a second heating, cooling to 20-30℃, transferring to a volumetric flask and using tertiary water to constant volume to obtain a sample solution;

[0024] S3, first adding H2O2 to soak the sample, then adding dilute HCl to perform a second reaction with an interval of less than 1 minute, performing a third heating after the reaction is completed, performing a fourth heating, cooling to 20-30℃, transferring to a volumetric flask and using tertiary water to constant volume to obtain a magnesium matrix solution;

[0025] S4, using the magnesium matrix solution in S3 to prepare standard solutions of Si, Al, Mn, Fe, Cu and Ni;

[0026] S5, using an ICP spectrometer and the standard solutions in S4 to establish a working curve;

[0027] S6, testing the sample solution obtained in S2;

[0028] In S2, the mass of the magnesium ingot sample, the volume of H2O2 and the volume of HCl are in a ratio of 1:3-10:30-54.

[0029] In the prior art, the ICP spectrometry method for analyzing impurity elements in native magnesium ingot does not include silicon elements, i.e., the method for dissolving the sample in the standard does not consider the analysis of silicon elements, and the method for dissolving the sample in the national standard is to first add hydrochloric acid, and then add hydrogen peroxide after the reaction is completed. In this process, magnesium silicide in the native magnesium ingot reacts with hydrochloric acid to generate silane (SiH4) gas, which causes the loss of silicon elements and affects the determination of the content.

[0030] The present application places the native magnesium ingot chip sample in hydrogen peroxide, so that the sample is in a strong oxidizing agent environment, then adds hydrochloric acid, and controls a specific ratio, so that the overall reaction is carried out in a strong oxidizing environment, and the generation of silane gas is inhibited, thereby improving the accuracy of silicon element analysis.

[0031] According to the present application, in S1, the thickness of the continuous chips is ≤0.1 mm, and the mass of the continuous chips is more than 4 times the mass of the magnesium ingot sample.

[0032] According to the application, in S2, the conditions of the first reaction include: the time of the first reaction is 3-8 min, and the temperature of the first reaction is ≥15℃.

[0033] The conditions of the first heating include: the time of the first heating is 1-3 min after micro boiling, and the temperature of the first heating is 100℃.

[0034] The conditions of the second heating include: the time of the second heating is 4-6 min after micro boiling, and the temperature of the second heating is 100℃.

[0035] According to the application, in S3, the ratio of the mass of the high-purity magnesium, the volume of H2O2 and the volume of HCl is 1:3-10:30-54.

[0036] The magnesium content of the high-purity magnesium is ≥99.999%.

[0037] According to the application, in S3, the conditions of the second reaction are the same as those of the first reaction.

[0038] The conditions of the third heating are the same as those of the first heating.

[0039] The conditions of the fourth heating are the same as those of the second heating.

[0040] According to the application, in S2 and S3, the concentration of the dilute HCl is 6 mol / L.

[0041] According to the application, in S4, the method for preparing the standard solution of each element is to respectively take Si, Al, Mn, Fe, Cu and Ni solutions with a concentration of 100 μg / mL into four 100 mL volumetric flasks, and the taking amounts are Si: 0 mL, 1 mL, 2 mL and 3 mL; Al: 0 mL, 1 mL, 2 mL and 3 mL; Mn: 0 mL, 1 mL, 2 mL and 3 mL; Fe: 0 mL, 1 mL, 2 mL and 3 mL; Cu: 0 mL, 0.5 mL, 1 mL and 1.5 mL; and Ni: 0 mL, 0.1 mL, 0.3 mL and 0.5 mL, and the four volumetric flasks are made up to the volume with the magnesium matrix solution in S3.

[0042] According to the application, in S4, the concentration of each element standard solution is as follows: Si: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, 3.0 μg / mL; Al: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, 3.0 μg / mL; Mn: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, 3.0 μg / mL; Fe: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, 3.0 μg / mL; Cu: 0 μg / mL, 0.5 μg / mL, 1.0 μg / mL, 1.5 μg / mL; Ni: 0 μg / mL, 0.1 μg / mL, 0.3 μg / mL, 0.5 μg / mL.

[0043] According to the application, in S5, the parameters of the ICP spectrometer include: radio frequency power of 0.8-1.2 kW, cooling gas flow rate of 15-25 L / min, auxiliary gas flow rate of 0.2-0.8 L / min, atomizing gas pressure of 0.1-0.3 MPa, sample feeding peristaltic pump rotating speed of 10-40 r / min, and spectral integration time of 10-25 s.

[0044] Specifically, according to some preferred embodiments of the application, the radio frequency power is 1.1 kW, the cooling gas flow rate is 18 L / min, the auxiliary gas flow rate is 0.5 L / min, the atomizing gas pressure is 0.234 MPa, the sample feeding peristaltic pump rotating speed is 25 r / min, and the spectral integration time is 20 s.

[0045] According to the application, in S5, the element analysis spectral line of Si is 251.611 nm, the element analysis spectral line of Fe is 259.940 nm, the element analysis spectral line of Cu is 324.754 nm, the element analysis spectral line of Al is 396.152 nm, the element analysis spectral line of Mn is 251.611 nm, and the element analysis spectral line of Ni is 231.604 nm.

[0046] According to the application, the linear correlation coefficient of each element working curve is ≥0.9995.

[0047] In the application, the numerical value of each element mass fraction (ω) of the test sample solution is calculated by formula (1), and the numerical value of the blank sample is adjusted according to GB / T8170.

[0048] (1)

[0049] In the formula,

[0050] x - each element, including Si, Fe, Cu, Al, Mn and Ni;

[0051] ρ - sample solution concentration, unit: μg / mL;

[0052] ρ0 - test mass concentration of high-purity magnesium without silicon element, unit: μg / mL;

[0053] V - sample solution constant volume, unit: mL;

[0054] m0 - sample weighing mass, unit: g.

[0055] The technical solutions of the present application are described in further detail below in conjunction with the examples. Obviously, the examples described herein are only some of the embodiments of the present application and are not intended to limit the present application. Based on the examples in the present application, all other examples implemented by those of ordinary skill in the art without making creative improvements fall within the protection scope of the present application.

[0056] Example 1

[0057] The sample uses a primary magnesium ingot spectroscopy standard sample produced by Southwest Aluminum Co., Ltd., numbered E4137, with the mass fraction of each element being Si: 0.030±0.003%; Al: 0.0082±0.0005%; Mn: 0.017±0.002%; Fe: 0.0055±0.0008%; Cu: 0.0039±0.0003%; and Ni: 0.0013±0.0004%. The sample is processed by turning, and the specific operation process is as follows:

[0058] The oxide film on the surface of the primary magnesium ingot spectroscopy standard sample is removed to ensure that the metal matrix of the sampling area is fully exposed. The metal debris is processed by a lathe to control the thickness of the metal debris to be ≤0.1 mm, and the debris sample of 5.2 g is obtained.

[0059] The debris sample is thoroughly mixed, 0.5000 g of the sample is weighed and placed in a 250 mL glass beaker, 2 mL of hydrogen peroxide is added to soak the sample, 20 mL of dilute hydrochloric acid is further added, a surface dish is placed on the beaker, the solution is reacted at 23°C for 5 minutes, the solution is heated to micro-boiling at 100°C and kept for 1 minute, and the surface dish and the inner wall of the beaker are washed with tertiary water. The solution is continuously heated to micro-boiling at 100°C and kept for 5 minutes, the heating is stopped, and the solution is cooled to 23°C. The cooled solution is transferred to a 100 mL volumetric flask, and the volume is adjusted with tertiary water. This solution is the sample solution to be tested.

[0060] Take 0.5000 g of high-purity magnesium scrap sample, place it in a 250 mL glass beaker, add 2 mL of hydrogen peroxide, soak the sample, then add 20 mL of dilute hydrochloric acid, cover the beaker with a watch glass, and react at 23°C for 5 minutes. Heat the solution to a slight boil at 100°C for 1 minute, rinse the watch glass and the inner wall of the beaker with triple distilled water. Continue heating the solution to a slight boil at 100°C for 5 minutes, stop heating, and allow the solution to cool to 23°C. Move the cooled solution into a 100 mL volumetric flask, and use triple distilled water to make up the volume. This solution is the blank sample solution.

[0061] Take 2.5000 g of high-purity magnesium scrap sample, place it in a 500 mL glass beaker, add 10 mL of hydrogen peroxide, soak the sample, then add 100 mL of dilute hydrochloric acid, cover the beaker with a watch glass, and react at 23°C for 5 minutes. Heat the solution to a slight boil for 1 minute, rinse the watch glass and the inner wall of the beaker with triple distilled water. Continue heating the solution to a slight boil for 5 minutes, stop heating, and allow the solution to cool to 23°C. Move the cooled solution into a 500 mL volumetric flask, and use triple distilled water to make up the volume. This solution is the magnesium matrix solution.

[0062] The ratio of the mass of the scrap sample to the volume of hydrogen peroxide and the volume of dilute hydrochloric acid for the test sample solution, the blank sample solution, and the magnesium matrix solution is 1:4:40.

[0063] Take four 100 mL volumetric flasks, and add Si, Al, Mn, Fe, Cu, and Ni solutions with a concentration of 100 μg / mL to the four 100 mL volumetric flasks, respectively. The amounts removed are Si: 0 mL, 1 mL, 2 mL, and 3 mL; Al: 0 mL, 1 mL, 2 mL, and 3 mL; Mn: 0 mL, 1 mL, 2 mL, and 3 mL; Fe: 0 mL, 1 mL, 2 mL, and 3 mL; Cu: 0 mL, 0.5 mL, 1 mL, and 1.5 mL; and Ni: 0 mL, 0.1 mL, 0.3 mL, and 0.5 mL. Use the magnesium matrix solution to make up the volume of the four volumetric flasks. This set of solutions is the standard solution curve solution, and the concentrations are Si: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, and 3.0 μg / mL; Al: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, and 3.0 μg / mL; Mn: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, and 3.0 μg / mL; Fe: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, and 3.0 μg / mL; Cu: 0 μg / mL, 0.5 μg / mL, 1.0 μg / mL, and 1.5 μg / mL; and Ni: 0 μg / mL, 0.1 μg / mL, 0.3 μg / mL, and 0.5 μg / mL.

[0064] The main parameter settings on the ICP spectrometer are as follows: radio frequency power 1.1 kW, cooling gas flow rate 18 L / min, auxiliary gas flow rate 0.5 L / min, atomizing gas pressure 0.234 MPa, sample feeding peristaltic pump speed 25 r / min, and spectral integration time 20 s. The element analysis wavelength spectral lines are as follows: Si: 251.611 nm, Fe: 259.940 nm, Cu: 324.754 nm, Al: 396.152 nm, Mn: 251.611 nm, and Ni: 231.604 nm. The analysis curve solution is used to establish the working curve of each element, and the linear correlation coefficients of the working curves of the elements are all greater than or equal to 0.9998.

[0065] The test sample solution and the blank sample solution are analyzed, and the analysis results are calculated by formula (1), and the mass fractions of each element are as follows: Si: 0.032%; Al: 0.0085%; Mn: 0.016%; Fe: 0.0048%; Cu: 0.0036%; and Ni: 0.0011%. The results meet the allowable range of the standard sample.

[0066] Example 2

[0067] The test sample is a primary magnesium ingot spectroscopy standard sample produced by Southwest Aluminum Co., Ltd., and the number is E4131. The mass fractions of each element are as follows: Si: 0.011±0.001%; Al: 0.011±0.002%; Mn: 0.017±0.001%; Fe: 0.0028±0.0005%; and Cu: 0.0012±0.0002%. The test sample is processed by turning, and the specific operation process is as follows:

[0068] The oxide film on the surface of the primary magnesium ingot spectroscopy standard sample is removed to ensure that the metal matrix of the sampling area is fully exposed. The metal chips are processed by a lathe, and the thickness of the metal chips is controlled to be less than or equal to 0.1 mm. The chip test sample is processed to obtain 5.5 g of chips.

[0069] The chip test sample is thoroughly mixed, 0.5000 g of the test sample is weighed, and placed in a 250 mL glass beaker. 2 mL of hydrogen peroxide is added to soak the test sample, and then 20 mL of dilute hydrochloric acid is added. A watch glass is placed on the beaker, and the solution is reacted at 23℃ for 5 minutes. The solution is heated to a slight boil at 100℃ for 1 minute, and the watch glass and the inner wall of the beaker are washed with tertiary water. The solution is continuously heated to a slight boil at 100℃ for 5 minutes, the heating is stopped, and the solution is cooled to 23℃. The cooled solution is transferred to a 100 mL volumetric flask, and the volume is adjusted with tertiary water. This solution is the test sample solution.

[0070] Take 0.5000 g of high-purity magnesium scrap sample, place it in a 250 mL glass beaker, add 2 mL of hydrogen peroxide, soak the sample, then add 20 mL of dilute hydrochloric acid, cover the beaker with a watch glass, and react at 23°C for 5 minutes. Heat the solution to a slight boil at 100°C for 1 minute, rinse the watch glass and the inner wall of the beaker with triple distilled water. Continue heating the solution to a slight boil at 100°C for 5 minutes, stop heating, and allow the solution to cool to 23°C. Move the cooled solution into a 100 mL volumetric flask, and use triple distilled water to make up the volume. This solution is the blank sample solution.

[0071] Take 2.5000 g of high-purity magnesium scrap sample, place it in a 500 mL glass beaker, add 10 mL of hydrogen peroxide, soak the sample, then add 100 mL of dilute hydrochloric acid, cover the beaker with a watch glass, and react at 23°C for 5 minutes. Heat the solution to a slight boil for 1 minute, rinse the watch glass and the inner wall of the beaker with triple distilled water. Continue heating the solution to a slight boil for 5 minutes, stop heating, and allow the solution to cool to 23°C. Move the cooled solution into a 500 mL volumetric flask, and use triple distilled water to make up the volume. This solution is the magnesium matrix solution.

[0072] The ratio of the mass of the scrap sample to the volume of hydrogen peroxide and the volume of dilute hydrochloric acid for the test sample solution, the blank sample solution, and the magnesium matrix solution is 1:4:40.

[0073] Take four 100 mL volumetric flasks, and add Si, Al, Mn, Fe, Cu, and Ni solutions with a concentration of 100 μg / mL to the four 100 mL volumetric flasks, respectively. The amounts removed are Si: 0 mL, 1 mL, 2 mL, and 3 mL; Al: 0 mL, 1 mL, 2 mL, and 3 mL; Mn: 0 mL, 1 mL, 2 mL, and 3 mL; Fe: 0 mL, 1 mL, 2 mL, and 3 mL; Cu: 0 mL, 0.5 mL, 1 mL, and 1.5 mL; and Ni: 0 mL, 0.1 mL, 0.3 mL, and 0.5 mL. Use the magnesium matrix solution to make up the volume of the four volumetric flasks. This set of solutions is the standard solution curve solution, and the concentrations are Si: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, and 3.0 μg / mL; Al: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, and 3.0 μg / mL; Mn: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, and 3.0 μg / mL; Fe: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, and 3.0 μg / mL; Cu: 0 μg / mL, 0.5 μg / mL, 1.0 μg / mL, and 1.5 μg / mL; and Ni: 0 μg / mL, 0.1 μg / mL, 0.3 μg / mL, and 0.5 μg / mL.

[0074] The main parameter settings on the ICP spectrometer are as follows: radio frequency power 1.1 kW, cooling gas flow rate 18 L / min, auxiliary gas flow rate 0.5 L / min, atomizing gas pressure 0.234 MPa, sample feeding peristaltic pump speed 25 r / min, and spectral integration time 20 s. The element analysis wavelength spectral lines are as follows: Si: 251.611 nm, Fe: 259.940 nm, Cu: 324.754 nm, Al: 396.152 nm, Mn: 251.611 nm, and Ni: 231.604 nm. The analysis curve solution is used to establish the working curve of each element, and the linear correlation coefficients of the working curves of the elements are all greater than or equal to 0.9997.

[0075] The test sample solution and the blank sample solution are analyzed, and the analysis results are calculated by formula (1), and the mass fractions of each element are as follows: Si: 0.010%; Al: 0.010%; Mn: 0.018%; Fe: 0.0030%; and Cu: 0.0010%. The results meet the allowable range of the standard sample.

[0076] Example 3

[0077] The test sample is a primary magnesium ingot spectroscopy standard sample produced by Southwest Aluminum Co., Ltd., and the number is E4132. The mass fractions of each element are as follows: Si: 0.062±0.003%; Fe: 0.027±0.001%; Cu: 0.0077±0.0003%; and Ni: 0.011±0.001%. The turning method is used for sample processing, and the specific operation process is as follows:

[0078] The oxide film on the surface of the primary magnesium ingot spectroscopy standard sample is removed to ensure that the metal matrix of the sampling area is fully exposed. The metal chips are controlled to have a thickness of less than or equal to 0.1 mm, and the chip sample of 5.0 g is obtained by turning.

[0079] The chip sample is thoroughly mixed, 0.5000 g of the sample is weighed, and placed in a 250 mL glass beaker. 2 mL of hydrogen peroxide is added to soak the sample, and then 20 mL of dilute hydrochloric acid is added. A surface dish is placed on the beaker, and the solution is reacted at 23℃ for 5 minutes. The solution is heated to a slight boil at 100℃ for 1 minute, and the surface dish and the inner wall of the beaker are washed with tertiary water. The solution is continuously heated to a slight boil at 100℃ for 5 minutes, and the heating is stopped and the solution is cooled to 23℃. The cooled solution is transferred to a 100 mL volumetric flask, and the volume is adjusted with tertiary water. This solution is the test sample solution.

[0080] Take 0.5000 g of high-purity magnesium scrap sample, place it in a 250 mL glass beaker, add 2 mL of hydrogen peroxide, soak the sample, then add 20 mL of dilute hydrochloric acid, cover the beaker with a watch glass, and react at 23°C for 5 minutes. Heat the solution to a slight boil at 100°C for 1 minute, rinse the watch glass and the inner wall of the beaker with triple distilled water. Continue heating the solution to a slight boil at 100°C for 5 minutes, stop heating, and allow the solution to cool to 23°C. Move the cooled solution into a 100 mL volumetric flask, and use triple distilled water to make up the volume. This solution is the blank sample solution.

[0081] Take 2.5000 g of high-purity magnesium scrap sample, place it in a 500 mL glass beaker, add 10 mL of hydrogen peroxide, soak the sample, then add 100 mL of dilute hydrochloric acid, cover the beaker with a watch glass, and react at 23°C for 5 minutes. Heat the solution to a slight boil for 1 minute, rinse the watch glass and the inner wall of the beaker with triple distilled water. Continue heating the solution to a slight boil for 5 minutes, stop heating, and allow the solution to cool to 23°C. Move the cooled solution into a 500 mL volumetric flask, and use triple distilled water to make up the volume. This solution is the magnesium matrix solution.

[0082] The ratio of the mass of the scrap sample to the volume of hydrogen peroxide and the volume of dilute hydrochloric acid for the test sample solution, the blank sample solution, and the magnesium matrix solution is 1:4:40.

[0083] Take four 100 mL volumetric flasks, and add Si, Al, Mn, Fe, Cu, and Ni solutions with a concentration of 100 μg / mL to the four 100 mL volumetric flasks, respectively. The amounts removed are Si: 0 mL, 1 mL, 2 mL, and 3 mL; Al: 0 mL, 1 mL, 2 mL, and 3 mL; Mn: 0 mL, 1 mL, 2 mL, and 3 mL; Fe: 0 mL, 1 mL, 2 mL, and 3 mL; Cu: 0 mL, 0.5 mL, 1 mL, and 1.5 mL; and Ni: 0 mL, 0.1 mL, 0.3 mL, and 0.5 mL. Use the magnesium matrix solution to make up the volume of the four volumetric flasks. This set of solutions is the standard solution curve solution, and the concentrations are Si: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, and 3.0 μg / mL; Al: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, and 3.0 μg / mL; Mn: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, and 3.0 μg / mL; Fe: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, and 3.0 μg / mL; Cu: 0 μg / mL, 0.5 μg / mL, 1.0 μg / mL, and 1.5 μg / mL; and Ni: 0 μg / mL, 0.1 μg / mL, 0.3 μg / mL, and 0.5 μg / mL.

[0084] The main parameter settings on the ICP spectrometer are as follows: radio frequency power 1.1 kW, cooling gas flow rate 18 L / min, auxiliary gas flow rate 0.5 L / min, atomizing gas pressure 0.234 MPa, sample feeding peristaltic pump speed 25 r / min, and spectral integration time 20 s. The element analysis wavelength spectral lines are as follows: Si: 251.611 nm, Fe: 259.940 nm, Cu: 324.754 nm, Al: 396.152 nm, Mn: 251.611 nm, and Ni: 231.604 nm. The analysis curve solution is used to establish the working curve of each element, and the linear correlation coefficients of the working curves of the elements are all greater than or equal to 0.9997.

[0085] The test sample solution and the blank sample solution are analyzed, and the analysis results are calculated by formula (1), and the mass fractions of each element are as follows: Si: 0.060%; Fe: 0.027%; Cu: 0.0080%; and Ni: 0.010%. The results meet the allowable range of the standard sample.

[0086] Example 4

[0087] The sample is determined according to the method of Example 1, except that the ratio of the sample weight of the test sample solution, the blank sample solution, the magnesium matrix solution, the volume of hydrogen peroxide and the volume of dilute hydrochloric acid is 1:3:30.

[0088] The test sample solution and the blank sample solution are analyzed, and the analysis results are calculated by formula (1), and the mass fractions of each element are as follows: Si: 0.027%; Al: 0.0080%; Mn: 0.015%; Fe: 0.0048%; Cu: 0.0037%; and Ni: 0.0010%. The results meet the allowable range of the standard sample.

[0089] Example 5

[0090] The sample is determined according to the method of Example 1, except that the ratio of the sample weight of the test sample solution, the blank sample solution, the magnesium matrix solution, the volume of hydrogen peroxide and the volume of dilute hydrochloric acid is 1:10:54.

[0091] The test sample solution and the blank sample solution are analyzed, and the analysis results are calculated by formula (1), and the mass fractions of each element are as follows: Si: 0.033%; Al: 0.0087%; Mn: 0.018%; Fe: 0.0062%; Cu: 0.0036%; and Ni: 0.0012%. The results meet the allowable range of the standard sample.

[0092] Comparative Example 1

[0093] The sample was determined according to the method of Example 1, except that after the spectral standard sample, the blank sample and the high-purity magnesium chip sample were placed in a glass beaker, 20 mL of dilute hydrochloric acid was first added, and after 3 minutes of reaction, 2 mL of hydrogen peroxide was added, and the reaction was carried out for 2 minutes, for a total of 5 minutes. The subsequent steps were exactly the same as in Example 1. The analysis results of the mass fraction of each element were Si: 0.021%; Al: 0.0084%; Mn: 0.016%; Fe: 0.0050%; Cu: 0.0042%; and Ni: 0.0010%. Lower than the allowable range of the standard sample.

[0094] Comparative Example 2

[0095] The sample was determined according to the method of Example 2, except that after the spectral standard sample, the blank sample and the high-purity magnesium chip sample were placed in a glass beaker, 20 mL of dilute hydrochloric acid was first added, and after 3 minutes of reaction, 2 mL of hydrogen peroxide was added, and the reaction was carried out for 2 minutes, for a total of 5 minutes. The subsequent steps were exactly the same as in Example 2. The analysis results of the mass fraction of each element were Si: 0.009%; Al: 0.011%; Mn: 0.017%; Fe: 0.0032%; Cu: 0.0011%. Lower than the allowable range of the standard sample.

[0096] Comparative Example 3

[0097] The sample was determined according to the method of Example 3, except that after the spectral standard sample, the blank sample and the high-purity magnesium chip sample were placed in a glass beaker, 20 mL of dilute hydrochloric acid was first added, and after 3 minutes of reaction, 2 mL of hydrogen peroxide was added, and the reaction was carried out for 2 minutes, for a total of 5 minutes. The subsequent steps were exactly the same as in Example 2. The analysis results of the mass fraction of each element were Si: 0.048%; Fe: 0.026%; Cu: 0.0074%; and Ni: 0.011%. Lower than the allowable range of the standard sample.

[0098] Comparative Example 4

[0099] The sample was determined according to the method of Example 1, except that the ratio of the mass of the test sample solution, the blank sample solution and the magnesium matrix solution, the volume of hydrogen peroxide and the volume of dilute hydrochloric acid was 1:2:20.

[0100] The test sample solution and the blank sample solution were analyzed, and the analysis results were calculated by formula (1), and the mass fraction of each element was Si: 0.022%; Al: 0.0078%; Mn: 0.015%; Fe: 0.0046%; Cu: 0.0035%; and Ni: 0.0005%. Not in line with the allowable range of the standard sample.

[0101] Comparative Example 5

[0102] The sample is determined according to the method of Example 1, except that the ratio of the sample solution, the blank sample solution, the scrap sample of the magnesium matrix solution, the volume of hydrogen peroxide and the volume of dilute hydrochloric acid is 1:12:60. During the analysis process, a large amount of white magnesium chloride crystals is precipitated on the surface of the rectangular tube and the top end of the center tube, which blocks the center tube of the rectangular tube, affects the stability of the instrument flame, reduces the service life of the instrument, and cannot use more than this proportion of hydrochloric acid.

[0103] By comparing the examples and the comparative examples, it can be seen that the comparative example 1 adopts the method of adding HCl first and then adding H2O2, and the disadvantage is that the measured value of silicon element is lower than the allowable range of the standard sample, while the example 1 adopts the specific method of the application, and the analysis results of impurity elements meet the allowable range of the standard sample, and the analysis results are accurate and reliable. During the ICP spectrum analysis test of silicon element in aluminum alloy, the inventor found that the analysis by the standard method of adding dilute hydrochloric acid first and then adding hydrogen peroxide produced methylsilane gas during the reaction process, which caused the analysis result of silicon element to be low. Through the test, it is found that the method of adding hydrogen peroxide first and then adding dilute hydrochloric acid can reduce the loss of silicon element and improve the analysis accuracy of silicon element. The inventor has thus generated the creative idea of applying the previous treatment method to the ICP spectrum detection test of silicon element in raw magnesium ingot, which has a good effect and improves the analysis accuracy of silicon element.

[0104] The application adopts the pretreatment method of adding dilute hydrochloric acid under the strong oxidizing environment provided by hydrogen peroxide and the matrix matching method to establish the working curve, and measures the content of impurity elements in raw magnesium ingot by the standard curve method of ICP spectrometer. The method has high analysis precision, short analysis period, few types of chemical drugs involved, and the upper limit of the analysis range of each element can reach Si: 0.06%, Al: 0.06%, Mn: 0.06%, Fe: 0.06%, Cu: 0.03%, and Ni: 0.01%.

[0105] The above is only a preferred specific embodiment of the application, but the protection scope of the application is not limited thereto, and any person skilled in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the application within the technical range disclosed by the application, which should be covered within the protection scope of the application.

Claims

1. A method of testing the content of impurity elements in a native magnesium ingot by ICP spectrometry, characterized in that, The method comprises: S1, removing the surface oil and oxide film of the primary magnesium ingot, obtaining continuous chips by mechanical processing, and mixing the continuous chips; S2, taking a magnesium ingot sample from the continuous chips, first adding H2O2 to soak the sample, then adding dilute HCl to perform a first reaction with an interval of less than 1 minute, performing a first heating after the reaction, performing a second heating, cooling to 20-30 DEG C, transferring to a volumetric flask, and using tertiary water to make up the volume to obtain a sample solution; S3, first adding H2O2 to soak the sample, then adding dilute HCl to perform a second reaction with an interval of less than 1 minute, performing a third heating after the reaction, performing a fourth heating, cooling to 20-30 DEG C, transferring to a volumetric flask, and using tertiary water to make up the volume to obtain a magnesium matrix solution; S4, using the magnesium matrix solution in S3 to prepare standard solutions of Si, Al, Mn, Fe, Cu, and Ni; S5, using an ICP spectrometer and the standard solutions in S4 to establish a working curve; S6, testing the sample solution obtained in S2; In S2, the ratio of the mass of the magnesium ingot sample, the volume of H2O2, and the volume of HCl is 1:3-10:30-54.

2. The method of claim 1, wherein, In S1, the thickness of the continuous chips is ≤0.1 mm, and the mass of the continuous chips is more than 4 times the mass of the magnesium ingot sample.

3. The method of claim 1, wherein, In S2, the first reaction conditions include a first reaction time of 3-8 min and a first reaction temperature of ≥15 DEG C; The first heating conditions include a first heating time of 1-3 min after micro-boiling and a first heating temperature of 100 DEG C; The second heating conditions include a second heating time of 4-6 min after micro-boiling and a second heating temperature of 100 DEG C; In S2 and S3, the concentration of the dilute HCl is 6 mol / L.

4. The method of claim 1, wherein, In S3, the ratio of the mass of the high-purity magnesium, the volume of H2O2, and the volume of HCl is 1:3-10:30-54; The magnesium content of the high-purity magnesium is ≥99.999%.

5. The method of claim 1, wherein, In S3, the second reaction conditions are the same as the first reaction conditions; The third heating conditions are the same as the first heating conditions; The fourth heating conditions are the same as the second heating conditions.

6. The method of claim 1, wherein, In S4, the method for preparing the standard solutions of each element is to respectively transfer Si, Al, Mn, Fe, Cu, and Ni solutions with a concentration of 100 μg / mL to four 100 mL volumetric flasks, and the transfer amounts are Si: 0 mL, 1 mL, 2 mL, and 3 mL; Al: 0 mL, 1 mL, 2 mL, and 3 mL; Mn: 0 mL, 1 mL, 2 mL, and 3 mL; Fe: 0 mL, 1 mL, 2 mL, and 3 mL; Cu: 0 mL, 0.5 mL, 1 mL, and 1.5 mL; and Ni: 0 mL, 0.1 mL, 0.3 mL, and 0.5 mL, and the four volumetric flasks are made up to the volume using the magnesium matrix solution in S3.

7. The method of claim 1, wherein, In S4, the concentration of each element standard solution is as follows: Si: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, 3.0 μg / mL; Al: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, 3.0 μg / mL; Mn: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, 3.0 μg / mL; Fe: 0 μg / mL, 1.0 μg / mL, 2.0 μg / mL, 3.0 μg / mL; Cu: 0 μg / mL, 0.5 μg / mL, 1.0 μg / mL, 1.5 μg / mL; Ni: 0 μg / mL, 0.1 μg / mL, 0.3 μg / mL, 0.5 μg / mL.

8. The method of claim 1, wherein, In S5, the parameters of the ICP spectrometer include: radio frequency power of 0.8-1.2 kW, cooling gas flow rate of 15-25 L / min, auxiliary gas flow rate of 0.2-0.8 L / min, atomizing gas pressure of 0.1-0.3 MPa, sample feeding peristaltic pump rotating speed of 10-40 r / min, and spectral integration time of 10-25 s.

9. The method of claim 1, wherein, In S5, the element analysis spectral lines of Si, Fe, Cu, Al, Mn and Ni are 251.611 nm, 259.940 nm, 324.754 nm, 396.152 nm, 251.611 nm and 231.604 nm, respectively.