Method for measuring content of non-rare earth impurities in yttrium-iron alloy

Abstract

The invention relates to a method for determining the content of non-rare earth impurities in yttrium-iron alloy, and belongs to the technical field of yttrium-iron alloy element determination. The non-rare earth impurities comprise Ni, Cr and P. The method comprises the following steps: under set conditions, dissolving an yttrium-iron alloy sample by using hydrochloric acid, and fixing the volume to obtain a solution to be detected; preparing an iron matrix storage solution and an yttrium matrix storage solution so as to prepare a plurality of same iron and yttrium mixed storage solutions; the method comprises the following steps: respectively adding standard solutions which contain non-rare earth impurities and have different volumes into a plurality of same mixed storage solutions of iron and yttrium to obtain a series of standard solutions; determining an analysis spectral line of the non-rare earth impurities; and respectively measuring the luminous intensity of the non-rare earth impurities of the series of standard solutions and the solution to be measured on an analysis spectral line by using inductively coupled plasma emission spectrometry, drawing a standard curve of the non-rare earth impurities, and determining the content of the non-rare earth impurities in the yttrium-iron alloy sample. The method has the characteristics of high sensitivity and high accuracy in determination of Ni, Cr and P.

Description

Technical Field

[0001] The present application relates to the technical field of determination of yttrium-iron alloy elements, and in particular to a method for determining the content of non-rare earth impurities in yttrium-iron alloys. Background Art

[0002] Yttrium iron alloy is mainly used as an additive for steel, a spheroidizing agent for ductile iron, a vermicular cast iron, an additive for alloy cast iron, etc. Usually, yttrium iron contains more than 60% Y, rare earth impurities, non-rare earth impurities and the balance Fe. Rare earth impurities are mainly La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Non-rare earth impurities are mainly Al, Si, Mn, Ca, Mg, Ni, Cr, P, S, C, and O.

[0003] Whether in the quality control of yttrium ferro raw material procurement or in guiding steelmaking process operations, the chemical composition of yttrium ferroalloy needs to be tested and analyzed. However, in the production of iron-chromium-aluminum alloy steel, there is a lack of scientific production control and guidance data to control the content of Ni, Cr, and P elements in yttrium ferroalloy. At the same time, there is currently no mature method to detect the content of Ni, Cr, and P elements in yttrium ferroalloy. Summary of the invention

[0004] The present application provides a method for determining the content of non-rare earth impurities in yttrium-iron alloys to solve the following technical problems: providing a method for determining the content of nickel, chromium and phosphorus in yttrium-iron alloys.

[0005] In a first aspect, an embodiment of the present application provides a method for determining the content of non-rare earth impurities in a yttrium-iron alloy, wherein the non-rare earth impurities include Ni, Cr and P, and the method comprises:

[0006] Under set conditions, the yttrium-iron alloy sample is dissolved using hydrochloric acid, and then the solution obtained by the dissolution is fixed to a volume to obtain a solution to be tested;

[0007] preparing an iron matrix storage solution and an yttrium matrix storage solution;

[0008] According to the iron matrix storage solution and the yttrium matrix storage solution, a plurality of identical iron and yttrium mixed storage solutions are prepared;

[0009] Adding different volumes of standard solutions containing non-rare earth impurities to the same plurality of mixed stock solutions of iron and yttrium, respectively, to obtain a series of standard solutions;

[0010] Determining the analytical spectrum of the non-rare earth impurities;

[0011] Using inductively coupled plasma emission spectrometry to respectively measure the luminescence intensity of the non-rare earth impurities in the series of standard solutions at the analysis spectral lines, and draw a standard curve of the non-rare earth impurities;

[0012] Using the inductively coupled plasma emission spectrometry to measure the luminescence intensity of the non-rare earth impurities in the solution to be tested at the analysis spectrum line;

[0013] The non-rare earth impurity content of the yttrium-iron alloy sample is determined according to the standard curve.

[0014] Optionally, the setting conditions include: temperature of 30°C to 50°C, and time of 1 min to 5 min.

[0015] Optionally, the mass fraction of the hydrochloric acid is 50%, and the ratio of the mass M1 of the yttrium-iron alloy sample to the volume V1 of the hydrochloric acid is M1:V1 is 1:(5-200), and if the unit of M1 is g, the unit of V1 is ml.

[0016] Optionally, the preparation of the iron matrix storage solution comprises:

[0017] Using concentrated nitric acid to first dissolve the high-purity iron powder to obtain a first solution;

[0018] The first solution is subjected to a second dissolution using concentrated hydrochloric acid, and then the solution obtained by the second dissolution is fixed to a constant volume to obtain an iron matrix storage solution; wherein,

[0019] The ratio M2:V2:V3 of the mass M2 of the high-purity iron powder, the volume V2 of the concentrated nitric acid and the volume V3 of the concentrated hydrochloric acid is (0.25-1):(2-6):(6-18); if the unit of M2 is g, the units of V2 and V3 are ml.

[0020] Optionally, the ratio V2:V3 of the volume V2 of the concentrated nitric acid to the volume V3 of the concentrated hydrochloric acid is 1:3.

[0021] Optionally, the analytical spectrum of Ni is 231.604 nm; and / or,

[0022] The analytical spectrum of Cr is 267.716 nm; and / or,

[0023] The analytical spectrum line of P is 177.495 nm.

[0024] Optionally, the process parameters of the inductively coupled plasma emission spectrometry include: RF power of 1100W to 1300W, and auxiliary gas flow rate of 800mL / min to 1000mL / min.

[0025] Optionally, the mass fraction of yttrium in the mixed storage solution of iron and yttrium is 55% to 68%.

[0026] Optionally, the mass fraction of yttrium in the mixed storage solution of iron and yttrium is 60%, and the mass fraction of iron in the mixed storage solution of iron and yttrium is 35%.

[0027] Optionally, the concentration gradient of the non-rare earth impurities in the series of standard solutions is: 0.005%, 0.01%, 0.025%, 0.05%, 0.075%, 0.2%, 0.5%, 0.8%, and 1.2%.

[0028] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0029] The embodiment of the present application provides a method for determining the content of non-rare earth impurities in the yttrium-iron alloy, wherein the non-rare earth impurities include Ni, Cr and P. The method comprises: dissolving the yttrium-iron alloy sample using hydrochloric acid under set conditions, and then fixing the volume of the dissolved solution to obtain a solution to be tested; preparing an iron matrix storage solution and a yttrium matrix storage solution; configuring a plurality of identical mixed storage solutions of iron and yttrium according to the iron matrix storage solution and the yttrium matrix storage solution; adding different volumes of standard solutions containing non-rare earth impurities to the plurality of identical mixed storage solutions of iron and yttrium to obtain a series of standard solutions; determining the analysis spectrum of the non-rare earth impurities; using inductively coupled plasma emission spectrometry to respectively determine the luminescence intensity of the non-rare earth impurities of the series of standard solutions on the analysis spectrum, and drawing a standard curve of the non-rare earth impurities; using the inductively coupled plasma emission spectrometry to determine the luminescence intensity of the non-rare earth impurities of the solution to be tested on the analysis spectrum; and determining the non-rare earth impurity content of the yttrium-iron alloy sample according to the standard curve. Hydrochloric acid dissolves the yttrium-iron alloy sample under set conditions, and fully dissolves the non-rare earth impurities in the yttrium-iron alloy for subsequent analysis; the preparation of iron matrix storage solution, yttrium matrix storage solution and mixed storage solution can simulate the matrix environment of the yttrium-iron alloy to avoid the matrix effect that may interfere with the test results; a series of standard solutions can construct a standard solution system with a concentration gradient to establish the relationship between the non-rare earth impurity content and the luminescence intensity; determine the analysis spectrum of non-rare earth impurities to improve the sensitivity and accuracy of the determination of non-rare earth impurities; use inductively coupled plasma optical emission spectrometry (ICP-OES) to respectively determine the luminescence intensity of the non-rare earth impurities in the series of standard solutions in the analysis spectrum, establish a standard curve, and determine the luminescence intensity of the non-rare earth impurity analysis spectrum of the test solution to determine the non-rare earth impurity (Ni, Cr and P) content of the yttrium-iron alloy sample. This method can perform quantitative analysis through the standard curve, can more accurately measure the content of non-rare earth impurities in the yttrium-iron alloy, and reduces the interference of factors such as matrix effect on the test results by simulating the matrix environment and other measures. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0032] Figure 1 A schematic flow chart of a method for determining the content of non-rare earth impurities in a yttrium-iron alloy provided in an embodiment of the present application;

[0033] Figure 2 A standard curve of Ni element provided in Example 1 of the present application;

[0034] Figure 3 A standard curve of Cr element provided in Example 1 of the present application;

[0035] Figure 4 This is a standard curve of the P element provided in Example 1 of the present application. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0037] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0038] In the present application, unless otherwise specified, the directional words used, such as "upper" and "lower", refer specifically to the directions of the drawings in the accompanying drawings. In addition, in the description of the specification of the present application, the terms "include", "comprise", etc. mean "including but not limited to". In this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this article, "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. In the proportional relationship involved in this article, the parameters that need to be described by proportion should be understood as the first term of the proportional formula according to the order of description, and the proportional numbers should be understood as the second term of the proportional formula. For example, the mass ratio of substance A, substance B and substance C is 1:2:3, then substance A, substance B and substance C should correspond one by one to the proportional numbers in the proportional formula according to the order of description, that is, the mass of substance A: the mass of substance B: the mass of substance C = 1:2:3.

[0039] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0040] In a first aspect, the present invention provides a method for determining the content of non-rare earth impurities in yttrium-iron alloy, wherein the non-rare earth impurities include Ni, Cr and P. Figure 1 A flow chart of a method for determining the content of non-rare earth impurities in a yttrium-iron alloy provided in an embodiment of the present application; see Figure 1 , the method comprising:

[0041] S1. Under set conditions, using hydrochloric acid to dissolve the yttrium-iron alloy sample, and then fixing the volume of the solution obtained by the dissolution to obtain a solution to be tested;

[0042] In some embodiments, the set conditions include: a temperature of 30°C to 50°C and a time of 1 min to 5 min.

[0043] In the embodiment of the present application, the dissolution temperature can be 30°C to 50°C to ensure that the yttrium-iron alloy sample can be fully dissolved at an appropriate rate. If the temperature is lower than 30°C, the dissolution reaction rate may be too slow, resulting in incomplete dissolution; and the temperature is higher than 50°C, which may cause the volatilization of hydrochloric acid to intensify, on the one hand, causing the concentration of hydrochloric acid to change, affecting the dissolution effect, and on the other hand, the volatilized hydrochloric acid gas may cause harm to the experimenter and the environment. And the appropriate temperature helps to maintain the stability and repeatability of the reaction. The dissolution time can be 1min to 5min, which can control the degree of dissolution and fully make the dissolved solution clear. Exemplarily, the temperature can be 30°C, 32°C, 34°C, 36°C, 38°C, 40°C, 42°C, 44°C, 46°C, 48°C, 50°C, etc.; the time can be 1min, 2min, 3min, 4min, 5min, etc.

[0044] In some embodiments, the mass fraction of the hydrochloric acid is 50%, and the ratio of the mass M1 of the yttrium-iron alloy sample to the volume V1 of the hydrochloric acid is M1:V1 is 1:(5-200), and if the unit of M1 is g, the unit of V1 is ml.

[0045] In the embodiment of the present application, the mass fraction of 50% hydrochloric acid is the result of comprehensive consideration of dissolution ability and reaction stability. M1: V1 can be 1: (5 ~ 200), so that there is enough hydrochloric acid to dissolve the yttrium iron alloy sample. If M1: V1 is lower than 1 / 200, although complete dissolution can be guaranteed, it will lead to excessive hydrochloric acid in the solution, which may cause the liquid content to exceed 100ml during constant volume, and constant volume can only be performed after concentration, which increases the complexity of the experiment and the source of error; if M1: V1 is higher than 1 / 5, insufficient hydrochloric acid may occur, resulting in incomplete sample dissolution. Exemplary, the M1: V1 can be 1: 5, 1: 7, 1: 9, 1: 10, 1: 20, 1: 30, 1: 40, 1: 50, 1: 60, 1: 70, 1: 80, 1: 90, 1: 100, 1: 110, 1: 120, 1: 150, 1: 200, etc.

[0046] S2, preparing an iron matrix storage solution and an yttrium matrix storage solution;

[0047] In some embodiments, the preparation of the iron matrix storage solution comprises:

[0048] Using concentrated nitric acid to first dissolve the high-purity iron powder to obtain a first solution;

[0049] The first solution is subjected to a second dissolution using concentrated hydrochloric acid, and then the solution obtained by the second dissolution is fixed to a constant volume to obtain an iron matrix storage solution; wherein,

[0050] The ratio M2:V2:V3 of the mass M2 of the high-purity iron powder, the volume V2 of the concentrated nitric acid and the volume V3 of the concentrated hydrochloric acid is (0.25-1):(2-6):(6-18); if the unit of M2 is g, the units of V2 and V3 are ml.

[0051] In some embodiments, the ratio V2:V3 of the volume V2 of the concentrated nitric acid to the volume V3 of the concentrated hydrochloric acid is 1:3.

[0052] In the embodiment of the present application, concentrated nitric acid is used to dissolve high-purity iron powder because nitric acid has strong oxidizing properties, and the reaction of iron and concentrated nitric acid will generate products such as ferric nitrate, and concentrated hydrochloric acid has good acidity and certain reducibility. In the second dissolution step, hydrochloric acid can further react with the iron ions in the first solution or other iron compounds that may be present, so that the iron is more completely dissolved in the solution, ensuring that the iron matrix can exist in the solution in a suitable chemical form, which is convenient for subsequent constant volume to obtain an iron matrix storage solution.

[0053] M2:V2:V3 can be (0.25-1):(2-6):(6-18), which can give play to the synergistic effect of concentrated nitric acid and concentrated hydrochloric acid to fully dissolve the iron powder. Concentrated nitric acid and concentrated hydrochloric acid are added step by step to avoid violent reaction with the sample when mixed and added, and a large number of bubbles are generated, causing the sample to overflow the beaker. The step-by-step method of adding concentrated nitric acid and concentrated hydrochloric acid can reduce the reaction rate and ensure that the sample is completely dissolved. Exemplarily, the M2:V2:V3 can be 0.25:2:6, 1:4:10, 0.75:6:18, 0.5:5:15, etc.

[0054] S3, preparing a plurality of identical iron and yttrium mixed storage solutions according to the iron matrix storage solution and the yttrium matrix storage solution;

[0055] In some embodiments, the mass fraction of yttrium in the mixed storage solution of iron and yttrium is 55% to 68%.

[0056] In some embodiments, the mass fraction of yttrium in the mixed storage solution of iron and yttrium is 60%, and the mass fraction of iron in the mixed storage solution of iron and yttrium is 35%.

[0057] In the embodiment of the present application, the actual alloy composition ratio is simulated: in yttrium-iron alloy, the yttrium content is a key factor. The mass fraction of yttrium in the mixed storage solution of iron and yttrium is 55% to 68%, in order to simulate the actual composition of yttrium-iron alloy as much as possible. In this way, when it is used to detect non-rare earth impurities (Ni, Cr, P) in the future, the real matrix environment can be better simulated. Because in the actual yttrium-iron alloy, the ratio of yttrium to iron will affect the existence state and detection signal of impurities, the appropriate yttrium mass fraction range can make the mixed storage solution closer to the real yttrium-iron alloy in composition, reducing the detection error caused by matrix differences. This mass fraction range helps to optimize the detection conditions of inductively coupled plasma optical emission spectrometry (ICP-OES). Different element ratios will affect the excitation and emission processes in the plasma. And the interference of the matrix on the detection of impurity elements during the detection process can be minimized, thereby more accurately measuring the content of non-rare earth impurities and improving the repeatability of the experiment. Exemplarily, the mass fraction of yttrium in the mixed storage solution of iron and yttrium can be 55%, 57%, 59%, 60%, 61%, 63%, 65%, 68%, etc.

[0058] S4, adding different volumes of standard solutions containing non-rare earth impurities to the same plurality of mixed storage solutions of iron and yttrium, respectively, to obtain a series of standard solutions;

[0059] In some embodiments, the concentration gradient of the non-rare earth impurities in the series of standard solutions is: 0.005%, 0.01%, 0.025%, 0.05%, 0.075%, 0.2%, 0.5%, 0.8%, and 1.2%.

[0060] In the embodiments of the present application, the settings of these concentration gradients can cover a wider range of impurity content. In actual yttrium-iron alloys, the content of non-rare earth impurities (Ni, Cr, P) may vary due to factors such as raw materials and production processes. By setting a concentration gradient from 0.005% to 1.2%, whether it is a high-quality yttrium-iron alloy with a low content or a product with a relatively high impurity content, the corresponding reference standard can be found within the concentration range of this series of standard solutions. And the appropriate concentration gradient helps to improve the detection accuracy; the reasonable distribution of concentration gradients is conducive to drawing a more accurate standard curve; this concentration gradient range can also be used to verify the accuracy of the standard curve.

[0061] S5, determining the analysis spectrum of the non-rare earth impurities;

[0062] In some embodiments, the analytical spectrum of Ni is 231.604 nm; and / or,

[0063] The analytical spectrum of Cr is 267.716 nm; and / or,

[0064] The analytical spectrum line of P is 177.495 nm.

[0065] In the embodiments of the present application, for Ni, Cr, and P, selecting corresponding analysis spectral lines is beneficial to improving the sensitivity of inductively coupled plasma optical emission spectrometry (ICP-OES) detection, reducing spectral interference, and achieving accurate quantitative analysis with reliability and repeatability.

[0066] S6. Using inductively coupled plasma emission spectrometry, respectively measure the luminescence intensity of the non-rare earth impurities in the series of standard solutions at the analysis lines, and draw a standard curve of the non-rare earth impurities;

[0067] S7, using the inductively coupled plasma emission spectrometry to measure the luminescence intensity of the non-rare earth impurities in the solution to be tested at the analysis spectrum line;

[0068] S8. Determine the non-rare earth impurity content of the yttrium-iron alloy sample according to the standard curve.

[0069] In some embodiments, the process parameters of the inductively coupled plasma optical emission spectrometry include: RF power of 1100W to 1300W, and auxiliary gas flow rate of 800mL / min to 1000mL / min.

[0070] In the present application embodiment, inductively coupled plasma optical emission spectrometry (ICP-OES) is a powerful technique for elemental analysis. Its basic principle is based on atomic emission spectroscopy. First, the sample is introduced into a high-temperature inductively coupled plasma (ICP). ICP is a high-frequency magnetic field generated by a radio frequency generator, which ionizes the working gas (usually argon) flowing through the quartz torch to form a plasma. The temperature of this plasma is extremely high, reaching about 6000 to 10000K. When the sample is introduced into the plasma, the atoms in the sample are excited in a high-temperature environment. The electrons in the atoms will transition from the ground state to the high-energy state. The electrons in the high-energy state are unstable and will transition back to the ground state or a lower energy state in a short time, while emitting photons with a specific wavelength. The wavelength of these photons is related to the type of element. Different elements will emit light of different wavelengths, which forms the characteristic spectrum of the element.

[0071] RF (radio frequency) power is one of the key parameters in inductively coupled plasma optical emission spectrometry (ICP-OES). RF can be 1100W ~ 1300W, which can maintain the plasma in a suitable high temperature state, thereby obtaining a high excitation efficiency of sample atoms. And the appropriate RF power range helps to maintain the stability of the signal. The auxiliary gas flow rate has a stabilizing effect on the formation of plasma. The auxiliary gas flow rate can be 800mL / min ~ 1000mL / min, which can effectively help the formation of plasma and maintain its stability. The auxiliary gas is mainly argon, which plays a protective and stabilizing role in the outer layer of the plasma. The appropriate flow rate can ensure that the plasma burns stably in the torch tube and prevent the plasma from extinguishing or flickering. The auxiliary gas flow rate will also affect the process of introducing the sample into the plasma. The appropriate flow rate can evenly disperse the sample aerosol into the plasma to ensure that the atoms in the sample can be evenly excited in the plasma. Exemplarily, the RF power can be 1100 W, 1110 W, 1120 W, 1130 W, 1150 W, 1200 W, 1230 W, 1250 W, 1280 W, 1300 W, etc.; the auxiliary gas flow rate can be 800 mL / min, 850 mL / min, 900 mL / min, 950 mL / min, 1000 mL / min, etc.

[0072] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for the unrecorded specific conditions in the following examples are usually measured according to national standards. If there is no corresponding national standard, then carry out according to general international standards, normal conditions or according to the conditions recommended by the manufacturer.

[0073] Example 1

[0074] A method for determining the content of non-rare earth impurities in yttrium-iron alloy, wherein the non-rare earth impurities include Ni, Cr and P, comprising the steps of:

[0075] S11. Under set conditions, use hydrochloric acid to dissolve the yttrium-iron alloy sample, and then dilute the obtained solution to obtain a solution to be tested; specifically: weigh 0.1g±0.0001g of the yttrium-iron alloy sample, place it in a 100ml beaker, add 5ml of 50% hydrochloric acid by mass, and heat to dissolve (temperature is 30°C; time is 5min) to obtain a solution; remove the solution and cool it, transfer it to a 100ml volumetric flask, dilute it to the scale with water, and mix it to obtain the solution to be tested.

[0076] S21. Prepare iron matrix storage solution and yttrium matrix storage solution; specifically: weigh 0.5g high-purity iron powder, place in a 250ml beaker, stir with a glass rod, slowly add 6ml concentrated nitric acid, then add 18ml concentrated hydrochloric acid, let stand until the solid powder is decomposed and clear and cooled, transfer to a 250ml volumetric flask, dilute to the mark with water, mix well to obtain the iron matrix storage solution. Use standard solution NCS140028-2015 as the yttrium matrix storage solution;

[0077] S31, according to the iron matrix storage solution and the yttrium matrix storage solution, a plurality of identical iron and yttrium mixed storage solutions are prepared; specifically: 9 portions of the same iron and yttrium mixed storage solution with a mass fraction of 35% Fe and a mass fraction of 60% yttrium Y are prepared;

[0078] S41. Different volumes of standard solutions containing non-rare earth impurities were added to several identical mixed storage solutions of iron and yttrium to obtain a series of standard solutions; specifically, different volumes of standard solutions (NCS148776) containing Ni, Cr, and P were added to 9 identical mixed storage solutions of iron and yttrium, and diluted to 100 ml with water to prepare a series of standard solutions; the contents of Ni, Cr, and P in the series of standard solutions are shown in Table 1.

[0079] Table 1 Ni, Cr, P content in a series of standard solutions

[0080] 1 2 3 4 5 6 7 8 9 Ni content (%) 0.005 0.01 0.025 0.05 0.075 0.2 0.5 0.8 1.2 Cr content (%) 0.005 0.01 0.025 0.05 0.075 0.2 0.5 0.8 1.2 P content (%) 0.005 0.01 0.025 0.05 0.075 0.2 0.5 0.8 1.2

[0081] S51. Determine the analytical spectrum of non-rare earth impurities; wherein, the analytical spectrum of Ni is 231.604 nm; the analytical spectrum of Cr is 267.716 nm; and the analytical spectrum of P is 177.495 nm.

[0082] S61, using inductively coupled plasma emission spectrometry to respectively measure the luminescence intensity of the non-rare earth impurities in the series of standard solutions at the analysis spectrum line, and draw a standard curve of the non-rare earth impurities; specifically: introducing the standard series solutions into the inductively coupled plasma emission spectrometer in order of the concentration of Ni, Cr, and P elements from low to high, measuring the emission light intensity of the three elements at their respective analysis spectrum lines, and drawing a standard curve, Figure 2 A standard curve of Ni element provided in Example 1 of the present application; Figure 3 A standard curve of Cr element provided in Example 1 of the present application; Figure 4 A standard curve of P element provided in Example 1 of the present application; see Figures 2 to 4 ;

[0083] S71. Use inductively coupled plasma emission spectrometry to determine the luminescence intensity of non-rare earth impurities in the test solution in the analysis spectrum line; the process parameters of inductively coupled plasma emission spectrometry include: RF power of 1300W; cooling gas flow rate of 12000mL / min; auxiliary gas flow rate of 800mL / min; high salt atomization gas flow rate of 800mL / min; observation height of 8mm; peristaltic pump speed of 12r / min; sample flow rate of 2mL / min; argon purity of 99.99%.

[0084] S81. Determine the non-rare earth impurity content of the yttrium-iron alloy sample according to the standard curve. Specifically, introduce the test solution into the inductively coupled plasma emission spectrometer, measure the emission light intensity of Ni, Cr, and P elements under their respective analysis spectrum lines, and determine the content of Ni, Cr, and P elements in the sample according to the standard curve drawn in the previous step.

[0085] For the determination method of the non-rare earth impurity content in the yttrium-iron alloy provided in Example 1, please refer to Table 2 for the determination results.

[0086] Table 2 Measurement results

[0087] Element Name Ni Cr P Standard value (wt%) 0.004 0.003 0.004 Example 1 (wt%) 0.0041 0.0029 0.004

[0088] Example 2

[0089] Based on the disclosure of Example 1, Example 2 differs from Example 1 in that:

[0090] In step S11, heat to dissolve (temperature is 40°C; time is 3 minutes); in step S21, 4 ml of concentrated nitric acid is added, followed by 12 ml of concentrated hydrochloric acid.

[0091] For the determination method of the non-rare earth impurity content in the yttrium-iron alloy provided in Example 2, please refer to Table 3 for the determination results.

[0092] Table 3 Measurement results

[0093] Element Name Ni Cr P Standard value (wt%) 0.004 0.003 0.004 Example 2 (wt%) 0.004 0.0029 0.0039

[0094] Example 3

[0095] Based on the disclosure of Example 1, Example 3 differs from Example 1 in that:

[0096] In step S11, heat to dissolve (temperature is 50°C; time is 1 min); in step S21, 2 ml of concentrated nitric acid is added, followed by 6 ml of concentrated hydrochloric acid.

[0097] For the determination method of the non-rare earth impurity content in the yttrium-iron alloy provided in Example 3, please refer to Table 4 for the determination results.

[0098] Table 4 Measurement results

[0099] Element Name Ni Cr P Standard value (wt%) 0.004 0.003 0.004 Example 1 (wt%) 0.0041 0.003 0.0039

[0100] It can be seen from Examples 1 to 3 that the method for determining the content of non-rare earth impurities in yttrium-iron alloy provided in the examples of the present application can accurately determine the contents of nickel, chromium and phosphorus in the yttrium-iron alloy.

[0101] One or more technical solutions in the embodiments of the present application also have at least the following technical effects or advantages:

[0102] (1) The method for determining the content of non-rare earth impurities in yttrium-iron alloy has the characteristics of low detection limit, small matrix interference, wide linear range, high sensitivity and accuracy, and can accurately monitor the content of nickel, chromium and phosphorus in yttrium-iron alloy, providing scientific control data for production.

[0103] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for determining the content of non-rare earth impurities in yttrium-iron alloy, wherein the non-rare earth impurities include Ni, Cr and P, and the method comprises: Under set conditions, the yttrium-iron alloy sample is dissolved using hydrochloric acid, and then the solution obtained by the dissolution is fixed to a volume to obtain a solution to be tested; preparing an iron matrix storage solution and an yttrium matrix storage solution; According to the iron matrix storage solution and the yttrium matrix storage solution, a plurality of identical iron and yttrium mixed storage solutions are prepared; Adding different volumes of standard solutions containing non-rare earth impurities to the same plurality of mixed stock solutions of iron and yttrium, respectively, to obtain a series of standard solutions; Determining the analytical spectrum of the non-rare earth impurities; Using inductively coupled plasma emission spectrometry to respectively measure the luminescence intensity of the non-rare earth impurities in the series of standard solutions at the analysis spectral lines, and draw a standard curve of the non-rare earth impurities; Using the inductively coupled plasma emission spectrometry to measure the luminescence intensity of the non-rare earth impurities in the solution to be tested at the analysis spectrum line; The non-rare earth impurity content of the yttrium-iron alloy sample is determined according to the standard curve.

2. The method according to claim 1, characterized in that The setting conditions include: temperature of 30°C to 50°C, and time of 1 min to 5 min.

3. The method according to claim 1 or 2, characterized in that: The mass fraction of the hydrochloric acid is 50%, and the ratio of the mass M1 of the yttrium-iron alloy sample to the volume V1 of the hydrochloric acid is M1:V1 is 1:(5-200). If the unit of M1 is g, the unit of V1 is ml.

4. The method according to claim 1, characterized in that: The preparation of the iron matrix storage solution comprises: Using concentrated nitric acid to first dissolve the high-purity iron powder to obtain a first solution; The first solution is subjected to a second dissolution using concentrated hydrochloric acid, and then the solution obtained by the second dissolution is fixed to a constant volume to obtain an iron matrix storage solution; wherein, The ratio M2:V2:V3 of the mass M2 of the high-purity iron powder, the volume V2 of the concentrated nitric acid and the volume V3 of the concentrated hydrochloric acid is (0.25-1):(2-6):(6-18); if the unit of M2 is g, the units of V2 and V3 are ml.

5. The method according to claim 4, characterized in that The ratio V2:V3 of the volume V2 of the concentrated nitric acid to the volume V3 of the concentrated hydrochloric acid is 1:

3.

6. The method according to claim 1, characterized in that The analytical spectrum of Ni is 231.604 nm; and / or, The analytical spectrum of Cr is 267.716 nm; and / or, The analytical spectrum line of P is 177.495 nm.

7. The method according to claim 1, characterized in that The process parameters of the inductively coupled plasma emission spectrometry method include: RF power of 1100W to 1300W, and auxiliary gas flow rate of 800mL / min to 1000mL / min.

8. The method according to claim 1, characterized in that The mass fraction of yttrium in the mixed storage solution of iron and yttrium is 55% to 68%.

9. The method according to claim 8, characterized in that The mass fraction of yttrium in the mixed storage solution of iron and yttrium is 60%, and the mass fraction of iron in the mixed storage solution of iron and yttrium is 35%.

10. The method according to claim 1, characterized in that The concentration gradient of non-rare earth impurities in the series of standard solutions is: 0.005%, 0.01%, 0.025%, 0.05%, 0.075%, 0.2%, 0.5%, 0.8% and 1.2%.

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