Analysis method for measuring content of carbon element in manganese metal by infrared absorption method

Abstract

The invention provides an analysis method for measuring the content of carbon in manganese metal by an infrared absorption method. The analysis method comprises the following steps: sequentially carrying out acid washing, water washing and alcohol washing treatment on a manganese metal sample, and drying to obtain to-be-detected manganese metal; and sequentially placing the obtained to-be-tested metal manganese, the tungsten-tin fluxing agent, the pure iron fluxing agent and the pure copper fluxing agent into a furnace for melting treatment, and testing the content of the carbon element in the metal manganese by utilizing an infrared absorption method. The analysis method provided by the invention can realize stable detection of the low carbon content in the manganese metal sample, and meanwhile, the measurement accuracy is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of element analysis, and in particular relates to an analysis method for determining the carbon content in metallic manganese by an infrared absorption method. Background Art

[0002] Manganese is an important industrial metal with a variety of uses, mainly due to its high strength, corrosion resistance and magnetic properties. In modern industrial production, the performance and quality of manganese metal directly affect the service life and safety of the product. Therefore, the composition detection of manganese metal is particularly important, especially the detection of the content of elements such as carbon (C), silicon (Si) or sulfur (S).

[0003] At present, the factors that affect the accuracy and precision of carbon content analysis results are relatively complex. Improper handling of each test link will cause serious deviations in the test results, such as oxygen, crucible, flux, and sample processing steps. Among them, oxygen can be configured with high-purity oxygen (> 99.999%) to reduce external pollution sources, and the crucible can be pre-burned at high temperature to reduce the introduction of impurities. Therefore, flux and sample processing steps are the main sources of impurities and need to be strictly controlled to ensure the accuracy of the analysis results.

[0004] When conducting carbon and sulfur analysis, the selection, amount and order of addition of flux will have a significant impact on the analysis results. For example, choosing a suitable flux is crucial to ensure the complete combustion of the sample and reduce the amount of molten oxide powder, and the type of flux should be determined according to the heating method of the furnace, the melting point of the sample and the requirements of the thermodynamic reaction; the amount of flux added and the order of addition need to be precisely controlled to ensure the complete combustion of the sample and reduce the introduction of impurities.

[0005] However, the detection range of flux disclosed in the prior art is 0.0010% to 0.2%, and there are technical problems such as unstable detection results or too high detection limit for ultra-low carbon content analysis.

[0006] Therefore, in the art, there is an urgent need to develop a method for analyzing ultra-low carbon content to solve the above problems. Summary of the invention

[0007] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an analytical method for determining the carbon content in metallic manganese by infrared absorption method. The analytical method provided by the present invention can achieve stable detection of low carbon content in metallic manganese samples and improve the accuracy of measurement.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides an analytical method for determining the carbon content in metallic manganese by infrared absorption method, the analytical method comprising the following steps:

[0010] S1. The metal manganese sample is sequentially acid-washed, water-washed and alcohol-washed, and dried to obtain the metal manganese to be tested;

[0011] S2. The metal manganese to be tested, the tungsten-tin flux, the pure iron flux and the pure copper flux obtained in step S1 are sequentially placed in a furnace for melting treatment, and the carbon content in the metal manganese is tested by infrared absorption method.

[0012] On the one hand, the present invention effectively reduces the interference of impurities on the surface of the sample on the test results by optimizing the pretreatment steps of the metal manganese sample, and ultimately ensures the accuracy and reliability of the test results. On the other hand, the present invention reduces the influence of the early volatilization of metal manganese on the test results by regulating the type of flux and the placement order, and ensures that the sample can be completely melted without splashing during the preparation process.

[0013] In summary, the present invention significantly improves the quality and efficiency of sample preparation, reduces impurity interference, and enhances the accuracy and stability of the test results of low carbon content in metallic manganese by improving the preparation steps of metallic manganese samples, optimizing flux, and controlling the melting process.

[0014] In the present invention, the infrared absorption method exemplarily includes a high-frequency combustion-infrared absorption method, specifically, in the presence of a flux, oxygen is introduced into a high-frequency induction furnace, and the high-frequency furnace causes the sample to heat up and melt rapidly, releasing CO 2 The gas enters the infrared absorption cell and is measured by the carbon and sulfur analyzer. 2 The gas concentration can be used to obtain the carbon content in metallic manganese.

[0015] Preferably, the pickling process in step S1 includes treatment with a hydrochloric acid solution. The present invention can remove the oxide layer on the surface of the sample by only using a single hydrochloric acid solution.

[0016] In the present invention, the metal manganese sample is subjected to mechanical processing before pickling to obtain a block sample with no oil stain on the surface.

[0017] Preferably, the hydrochloric acid solution comprises hydrochloric acid and water.

[0018] Preferably, the volume ratio of hydrochloric acid to water is 1:(4-6), for example, it can be 1:4, 1:4.2, 1:4.5, 1:4.8, 1:5, 1:5.2, 1:5.5, 1:5.8, 1:6, etc., but is not limited to the listed technical solutions, and other unlisted values ​​within the above numerical ranges are also applicable.

[0019] Preferably, the number of pickling times in step S1 is not less than three times, for example, it can be three times, four times, five times, six times, seven times, eight times or nine times, but is not limited to the listed technical solutions, and other unlisted values ​​within the above numerical ranges are also applicable.

[0020] Preferably, the pickling time in step S1 is 1 minute each time.

[0021] In the present invention, the pickling may be performed under ultrasound.

[0022] Preferably, the number of water washings in step S1 is not less than three times, for example, three times, four times, five times, six times, seven times, eight times or nine times, etc., but is not limited to the listed technical solutions, and other unlisted values ​​within the above numerical ranges are also applicable.

[0023] Preferably, the washing time of each time in step S1 is 20s to 1min, for example, it can be 20s, 30s, 40s, 50s, 1min, etc., but it is not limited to the listed technical solutions, and other unlisted values ​​within the above numerical ranges are also applicable.

[0024] Preferably, the alcohol washing time in step S1 is 1 min to 2 min, for example, 1 min, 1.2 min, 1.5 min, 1.8 min, 2 min, etc., but is not limited to the listed technical solutions, and other unlisted values ​​within the above numerical ranges are also applicable.

[0025] In the present invention, the alcohol washing reagent exemplarily includes anhydrous ethanol.

[0026] The present invention regulates the pretreatment steps of the metal manganese sample so that impurities on the surface thereof are fully removed, thereby improving the accuracy and stability of the test.

[0027] Preferably, the mass ratio of the tungsten-tin flux, the pure iron flux and the pure copper flux in step S2 is 1:0.7:0.5, but is not limited to the listed technical solutions, and other unlisted values ​​within the above numerical ranges are also applicable.

[0028] In the present invention, by adjusting the mass ratio of tungsten-tin flux, pure iron flux and pure copper flux, the sample is melted better and less dust and powder are generated, thereby reducing the splashing of flux.

[0029] Preferably, the mass ratio of the total mass of the tungsten-tin flux, the pure iron flux and the pure copper flux to the metal manganese to be measured in step S2 is 2.2:(0.06-0.07), for example, it can be 2.2:0.06, 2.2:0.061, 2.2:0.062, 2.2:0.063, 2.2:0.064, 2.2:0.065, 2.2:0.066, 2.2:0.067, 2.2:0.068, 2.2:0.069, 2.2:0.07, etc., but is not limited to the listed technical solutions, and other unlisted values ​​within the above numerical ranges are equally applicable.

[0030] In the present invention, by regulating the mass ratio of the total mass of tungsten-tin flux, pure iron flux and pure copper flux to the metal manganese to be tested, the metal manganese sample to be tested can be fully melted in a quartz crucible, so that it can generate carbon dioxide in a sufficient oxygen environment, thereby accurately detecting the carbon content in the metal manganese sample to be tested through the infrared cell in the instrument.

[0031] Preferably, the particle size of the tungsten-tin flux in step S2 is 0.6 mm to 0.9 mm, for example, it can be 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, etc., but is not limited to the listed technical solutions, and other unlisted values ​​within the above numerical ranges are also applicable.

[0032] Preferably, the particle size of the pure iron flux in step S2 is 2.2 mm to 3.5 mm, for example, it can be 2.2 mm, 2.3 mm, 2.5 mm, 2.8 mm, 3 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, etc., but is not limited to the listed technical solutions, and other unlisted values ​​within the above numerical ranges are also applicable.

[0033] Preferably, the particle size of the pure copper flux in step S2 is 0.4 mm to 0.8 mm, for example, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, etc., but is not limited to the listed technical solutions, and other unlisted values ​​within the above numerical ranges are also applicable.

[0034] Preferably, the temperature of the melting treatment in step S2 is 1200°C to 1400°C, for example, 1200°C, 1250°C, 1300°C, 1350°C, 1400°C, etc.

[0035] Preferably, the melting treatment time in step S2 is 3 h to 5 h, for example, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, etc.

[0036] Preferably, the infrared absorption method in step S2 is performed using an infrared carbon-sulfur analyzer to test and obtain the carbon content in the metallic manganese.

[0037] Preferably, the working conditions of the infrared carbon and sulfur analyzer are: carrier flow rate 2.5L / min~3.5L / min, for example, it can be 2.5L / min, 2.6L / min, 2.8L / min, 3.0L / min, 3.2L / min, 3.5L / min, etc.; carrier gas pressure 30psi~35psi, for example, it can be 30psi, 31psi, 32psi, 33psi, 34psi, 35psi, etc.; power gas pressure 40psi~45psi, for example, it can be 40psi, 41psi, 42psi, 43psi, 44psi, 45psi, etc., but it is not limited to the listed technical solutions, and other unlisted values ​​within the above numerical ranges are equally applicable.

[0038] The present invention regulates the working conditions of the infrared carbon-sulfur analyzer so that the sample can be completely burned, the gas can be completely released, the analysis result is stable, and the volatilization of dust can be reduced.

[0039] Preferably, the analysis time of the infrared carbon and sulfur analyzer is 50s to 60s, for example, it can be 50s, 52s, 55s, 58s, 60s, etc.; the comparison level is 1 to 3, but is not limited to the listed technical solutions, and other unlisted values ​​within the above numerical ranges are also applicable.

[0040] Preferably, the concentration of carbon content in metallic manganese determined in the analysis method is ≥5ppm, for example, it can be 5ppm, 6ppm, 7ppm, 8ppm, 9ppm, 10ppm, 12ppm, 15ppm, 18ppm, etc., but is not limited to the listed technical solutions, and other unlisted values ​​within the above numerical ranges are also applicable.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The present invention provides an analysis method for determining the carbon content in metallic manganese by infrared absorption method. On the one hand, the present invention effectively reduces the interference of impurities on the surface of the sample on the test result by optimizing the pretreatment steps of the metallic manganese sample, and finally ensures the accuracy and reliability of the test result. On the other hand, the present invention reduces the influence of the early volatilization of metallic manganese on the test result by regulating the type of flux and the placement order of the flux, and ensures that the sample can be completely melted without splashing during the preparation process.

[0043] In summary, the present invention significantly improves the quality and efficiency of sample preparation, reduces impurity interference, and enhances the accuracy and stability of the test results of low carbon content in metallic manganese by improving the preparation steps of metallic manganese samples, optimizing flux, and controlling the melting process. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 The present invention provides a flow chart for determining the carbon content in metallic manganese by the infrared absorption method. DETAILED DESCRIPTION

[0045] The technical solution of the present invention is further described below by combining the accompanying drawings and specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0046] The purity of the tungsten-tin flux, the pure iron flux and the pure copper flux in the embodiments and comparative examples of the present invention is all above 99.99%, and the purity of the oxygen atmosphere is above 99.999%.

[0047] Example 1

[0048] This embodiment provides an analysis method for determining the carbon content in metallic manganese by infrared absorption method, and the analysis method comprises the following steps:

[0049] S1. The metal manganese sample and the hydrochloric acid solution were pickled three times, each pickling time was 1 min, and the volume ratio of hydrochloric acid to water was 1:5; after the end, it was rinsed with pure water three times (each washing time was 40 s) and washed with anhydrous ethanol for 1.5 min, and placed under an infrared lamp to dry for 3 min to obtain the metal manganese to be tested;

[0050] S2. 0.065 g of the manganese metal to be tested, 1 g of tungsten-tin flux, 0.7 g of pure iron flux and 0.5 g of pure copper flux obtained in step S1 are placed in a crucible in sequence and melt-treated at 1200° C. in an oxygen atmosphere for 4 hours, wherein the particle size of the tungsten-tin flux is 0.8 mm, the particle size of the pure iron flux is 3 mm, and the particle size of the pure copper flux is 0.6 mm; the released gas is collected and analyzed on an infrared carbon-sulfur analyzer using an infrared absorption method, and the content of carbon in the manganese metal is obtained by testing. The results are shown in Table 1, wherein the working conditions of the infrared carbon-sulfur analyzer are: carrier flow rate 3.1 L / min, carrier gas pressure 35 psi, power gas pressure 43 psi; the analysis time of the infrared carbon-sulfur analyzer is 60 s, and the comparison level is 1 to 3.

[0051] Example 2

[0052] This embodiment provides an analysis method for determining the carbon content in metallic manganese by infrared absorption method, and the analysis method comprises the following steps:

[0053] S1. The metal manganese sample and the hydrochloric acid solution were pickled three times, each pickling time was 1 min, and the volume ratio of hydrochloric acid to water was 1:4; after the end, it was rinsed with pure water three times (each washing time was 20 s) and washed with anhydrous ethanol for 1 min, and placed under an infrared lamp to dry for 3 min to obtain the metal manganese to be tested;

[0054] S2. 0.06 g of the manganese metal to be tested, 1 g of tungsten-tin flux, 0.7 g of pure iron flux and 0.5 g of pure copper flux obtained in step S1 are placed in a crucible in turn and melt-treated at 1200° C. in an oxygen atmosphere for 4 hours, wherein the particle size of the tungsten-tin flux is 0.6 mm, the particle size of the pure iron flux is 2.2 mm, and the particle size of the pure copper flux is 0.4 mm; the released gas is collected and analyzed on an infrared carbon-sulfur analyzer using an infrared absorption method, and the content of carbon in the manganese metal is obtained by testing. The results are shown in Table 1, wherein the working conditions of the infrared carbon-sulfur analyzer are: carrier flow rate 2.8 L / min, carrier gas pressure 32 psi, power gas pressure 42 psi; the analysis time of the infrared carbon-sulfur analyzer is 57 s, and the comparison level is 1 to 3.

[0055] Example 3

[0056] This embodiment provides an analysis method for determining the carbon content in metallic manganese by infrared absorption method, and the analysis method comprises the following steps:

[0057] S1. The metal manganese sample and the hydrochloric acid solution were pickled three times, each pickling time was 1 min, and the volume ratio of hydrochloric acid to water was 1:6; after the end, it was rinsed with pure water three times (each washing time was 1 min) and washed with anhydrous ethanol for 2 min, and placed under an infrared lamp to dry for 3 min to obtain the metal manganese to be tested;

[0058] S2. 0.07 g of the manganese metal to be tested, 1 g of tungsten-tin flux, 0.7 g of pure iron flux and 0.5 g of pure copper flux obtained in step S1 are placed in a crucible in turn and melt-treated at 1200° C. in an oxygen atmosphere for 4 hours, wherein the particle size of the tungsten-tin flux is 0.9 mm, the particle size of the pure iron flux is 3.5 mm, and the particle size of the pure copper flux is 0.8 mm; the released gas is collected and analyzed on an infrared carbon-sulfur analyzer using an infrared absorption method, and the content of carbon in the manganese metal is obtained by testing. The results are shown in Table 1, wherein the working conditions of the infrared carbon-sulfur analyzer are: carrier flow rate 3.5 L / min, carrier gas pressure 35 psi, power gas pressure 45 psi; the analysis time of the infrared carbon-sulfur analyzer is 50 s, and the comparison level is 1 to 3.

[0059] Example 4

[0060] The difference between this embodiment and embodiment 1 is that the mass ratio of tungsten-tin flux, pure iron flux and pure copper flux in step S2 is 1:0.3:0.2, and the rest is the same as embodiment 1.

[0061] Example 5

[0062] The difference between this embodiment and embodiment 1 is that the mass ratio of tungsten-tin flux, pure iron flux and pure copper flux in step S2 is 0.5:2:1, and the rest is the same as embodiment 1.

[0063] Example 6

[0064] The difference between this embodiment and embodiment 1 is that the mass of the metal manganese to be measured in step S2 is 0.03 g, and the rest is the same as embodiment 1.

[0065] Comparative Example 1

[0066] The difference between this comparative example and Example 1 is that in step S1, the hydrochloric acid solution is replaced by a nitric acid solution of the same content, and the rest is the same as Example 1.

[0067] Comparative Example 2

[0068] The difference between this comparative example and Example 1 is that the flux in step S2 does not contain pure copper (the mass ratio of tungsten tin to pure iron and the total mass added are the same as those in Example 1), and everything else is the same as that in Example 1.

[0069] Comparative Example 3

[0070] The difference between this comparative example and Example 1 is that the flux in step S2 does not contain pure iron (the mass ratio of tungsten tin to pure copper and the total mass added are the same as those in Example 1), and everything else is the same as that in Example 1.

[0071] Comparative Example 4

[0072] The difference between this comparative example and Example 1 is that the order of placing the materials in step S2 is to place pure iron flux, pure copper flux, metal manganese and tungsten-tin flux obtained in step S1, and the rest is the same as Example 1.

[0073] Comparative Example 5

[0074] The difference between this comparative example and Example 1 is that the order of placing the materials in step S2 is tungsten-tin flux, metallic manganese obtained in step S1, pure iron flux and pure copper flux, and the rest is the same as Example 1.

[0075] The carbon content in the metal manganese provided in the above embodiments and comparative examples was determined according to the conditions of the high-frequency induction furnace combustion infrared absorption method (standard state: current), such as Figure 1As shown, the gases released after the melting treatment of the above embodiments and comparative examples are subjected to anhydrous magnesium chloride to remove water in the gases, and then an infrared carbon-sulfur analyzer is used to test the sulfur content in the gases, and the sulfur dioxide in the gases is converted into sulfur trioxide, and absorbent cotton is used to absorb sulfur trioxide to remove sulfur-containing substances in the gases, and then an infrared carbon-sulfur analyzer is used to test the carbon content in the gases. The test results are shown in Table 1:

[0076] Table 1

[0077] Carbon content (ppm) Example 1 7.24 Example 2 8.13 Example 3 8.25 Example 4 6.67 Example 5 6.10 Example 6 6.92 Comparative Example 1 7.03 Comparative Example 2 5.71 Comparative Example 3 5.14 Comparative Example 4 6.48 Comparative Example 5 6.79

[0078] As can be seen from Table 1, the present invention realizes stable and efficient detection of carbon in metallic manganese by improving the preparation steps of metallic manganese samples and further regulating the type of flux, the order of adding materials and their ratio, especially the detection of carbon content in metallic manganese with a carbon content ≥5ppm has good detection accuracy and stability.

[0079] By comparing Example 1 with Example 4 and Example 5, it can be seen that the present invention optimizes the ratio of the flux, so that the sample can be melted better and less dust and powder are generated, thereby reducing the splashing of the flux.

[0080] By comparing Example 1 with Example 6, it can be seen that the present invention adjusts the ratio of the total mass of the metal manganese sample to be tested and the co-solvent so that the metal manganese sample to be tested can be fully melted in the quartz crucible, so that it can generate carbon dioxide in a sufficient oxygen environment, thereby accurately detecting the carbon content in the metal manganese sample to be tested through the infrared cell in the instrument.

[0081] Comparing Example 1 with Comparative Example 1, it can be seen that replacing the type of acid solution has the effect of improving the accuracy of determining the carbon content.

[0082] By comparing Example 1 with Comparative Examples 2 and 3, it can be seen that the present invention optimizes the type and ratio of the flux, and the presence of the flux can enable the metal manganese sample to be tested to be completely melted during the detection process, releasing the carbon element in the sample to react with oxygen.

[0083] By comparing Example 1 with Comparative Examples 4 and 5, it can be seen that the present invention ensures that the metal manganese sample to be tested can be completely burned by adjusting the placement order between the sample and various fluxes, and the detection baseline has no tailing peak and the peak shape is complete, so that the detection result is more accurate.

[0084] The applicant declares that the present invention illustrates the process method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned process steps, that is, it does not mean that the present invention must rely on the above-mentioned process steps to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An analytical method for determining the carbon content in metallic manganese by infrared absorption method, characterized in that: The analytical method comprises the following steps: S1. The metal manganese sample is sequentially acid-washed, water-washed and alcohol-washed, and dried to obtain the metal manganese to be tested; S2. The metal manganese to be tested, the tungsten-tin flux, the pure iron flux and the pure copper flux obtained in step S1 are sequentially placed in a furnace for melting treatment, and the carbon content in the metal manganese is tested by infrared absorption method.

2. The analysis method according to claim 1, characterized in that The pickling process in step S1 includes treating with a hydrochloric acid solution; Preferably, the hydrochloric acid solution comprises hydrochloric acid and water; Preferably, the volume ratio of hydrochloric acid to water is 1:(4-6).

3. The analysis method according to claim 1 or 2, characterized in that The number of pickling in step S1 is no less than three times; Preferably, the pickling time in step S1 is 1 minute each time.

4. The analysis method according to any one of claims 1 to 3, characterized in that The number of times of washing in step S1 is no less than three times; Preferably, the washing time in step S1 is 20s to 1min each time; Preferably, the alcohol washing time in step S1 is 1 min to 2 min.

5. The analysis method according to any one of claims 1 to 4, characterized in that The mass ratio of the tungsten-tin flux, the pure iron flux and the pure copper flux in step S2 is 1:0.7:0.5; Preferably, in step S2, the mass ratio of the total mass of the tungsten-tin flux, the pure iron flux and the pure copper flux to the metal manganese to be measured is 2.2:(0.06-0.07).

6. The analysis method according to any one of claims 1 to 5, characterized in that The particle size of the tungsten-tin flux in step S2 is 0.6 mm to 0.9 mm; Preferably, the particle size of the pure iron flux in step S2 is 2.2 mm to 3.5 mm; Preferably, the particle size of the pure copper flux in step S2 is 0.4 mm to 0.8 mm.

7. The analysis method according to any one of claims 1 to 6, characterized in that The temperature of the melting treatment in step S2 is 1200° C. to 1400° C.; Preferably, the melting treatment time in step S2 is 3 h to 5 h.

8. The analysis method according to any one of claims 1 to 7, characterized in that The infrared absorption method in step S2 is to use an infrared carbon-sulfur analyzer to perform analysis to test and obtain the carbon content in the metallic manganese.

9. The analysis method according to claim 8, characterized in that The working conditions of the infrared carbon and sulfur analyzer are: carrier flow rate 2.5L / min~3.5L / min, carrier gas pressure 30psi~35psi, power gas pressure 40psi~45psi; Preferably, the analysis time of the infrared carbon-sulfur analyzer is 50s-60s, and the comparison level is 1-3.

10. The analysis method according to any one of claims 1 to 9, characterized in that The concentration of carbon element content in metallic manganese determined in the analytical method is ≥5 ppm.

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