Method for rapidly determining chromium content in high-carbon ferro-chrome

Abstract

The invention belongs to the field of analysis and detection, and relates to a method for rapidly determining chromium content in high-carbon ferrochrome, which comprises the following steps: 1) crushing high-carbon ferrochrome and sieving to obtain high-carbon ferrochrome powder; (2) boric acid powder is used for bottoming, the high-carbon ferrochrome powder obtained in the step (1) is laid on the boric acid powder, pressing is conducted through a tablet press, and a pressed sheet sample is obtained; (3) analyzing the sheet sample obtained in the step (2) by adopting a qualitative and semi-quantitative method in a fluorescence spectrophotometer to obtain the sum of the mass percentage contents of the elements and the uncorrected mass percentage content of the chromium element; and 4) calculating the chromium content: CCr = CCr0 * 100% / (CC + SUQ). The method has the advantages that the sheet formed by pressing the high-carbon ferro-chrome sample is measured by adopting the fluorescence spectrophotometer, and the measurement result is corrected, so that the characterization method of the chromium content is finally obtained.

Description

Technical Field

[0001] This invention belongs to the field of analytical testing, and in particular relates to a method for rapidly determining the chromium content in high-carbon ferrochrome. Background Technology

[0002] High-carbon ferrochrome is an important ferroalloy raw material in the iron and steel metallurgical industry, widely used in the smelting of bearing steel, stainless steel, and other tool steels. Currently, the testing of high-carbon ferrochrome is mainly based on national and industry-related standards. Traditional wet analysis is complex, cumbersome, time-consuming, labor-intensive, and difficult to master, and is also susceptible to human error, making it difficult to meet the rapid and accurate alloy testing requirements of modern steelmaking production.

[0003] X-ray fluorescence spectrometers are characterized by fast analysis speed and convenient operation. They enable rapid analysis to meet production needs. The determination of chromium content in high-carbon ferrochrome using X-ray fluorescence spectroscopy can be achieved using either the fused pellet method or the pellet pressing method. Compared to the fused pellet method, the pellet pressing method offers faster sample preparation and lower cost, but its accuracy is somewhat lower. This is mainly because the pellet pressing method uses a qualitative / semi-quantitative determination method, which can detect most elements on the periodic table and has a wide measurable concentration range (10⁻⁶). -4 The non-destructive nature of this method (ranging from 100% to 100%) makes it an excellent testing method for understanding the composition and approximate content of unknown substances. However, its accuracy is often significantly lower than that of the fluorescence spectroscopy fusion method.

[0004] Therefore, this invention aims to improve the accuracy of qualitative and semi-quantitative determination methods by incorporating the carbon content in high-carbon ferrochrome into the summation calculation of the results, and to quickly obtain the chromium content with high accuracy through a simple correction formula. This solves the problem of poor accuracy in the tableting method and enables the results of the tableting method to reach the level of quantitative detection. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, the purpose of this invention is to provide a method for rapidly determining the chromium content in high-carbon ferrochrome. By incorporating the carbon content in high-carbon ferrochrome into the result summation calculation, the chromium content can be quickly obtained with high accuracy through simple correction calculations. This improves the accuracy of qualitative and semi-quantitative determination methods, solves the problem of poor accuracy in the tableting method, and enables the results of the tableting method to reach the level of quantitative detection.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A rapid method for determining the chromium content in high-carbon ferrochrome includes the following steps:

[0008] 1) High-carbon ferrochrome alloy is pulverized and sieved to obtain high-carbon ferrochrome powder;

[0009] 2) Boric acid powder is used as a base, and high carbon ferrochrome powder obtained in step 1) is spread on top. The powder is then pressed by a tablet press to obtain a pressed sheet sample.

[0010] 3) The thin-film sample obtained in step 2) was analyzed using a qualitative and semi-quantitative method in a fluorescence spectrometer to obtain the total mass percentage of elements and the uncorrected mass percentage of chromium.

[0011] 4) Calculate the chromium content:

[0012] C Cr =C Cr0 ×100% / (C) C +S UQ );

[0013] In the formula: C Cr The percentage of chromium by mass; C C Carbon content (C) is the percentage of carbon by mass. Cr0 The uncorrected mass percentage of chromium; S UQ It represents the total percentage of elements by mass.

[0014] The high-carbon ferrochrome alloy described in step 1) is crushed and then passed through a 120-200 mesh sieve.

[0015] The carbon content mentioned in step 4) is measured using any current national or industry standard.

[0016] The tablet press described in step 2) has a pressing pressure of 30-40 MPa and a pressing time of 30-60 seconds.

[0017] The thin film sample obtained in step 2) is stored in a desiccator.

[0018] In step 2), the boric acid powder is an analytical grade reagent; the thickness of the high-carbon ferrochrome powder is more than 1 mm.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. This invention uses a fluorescence spectrometer to measure the chromium content in pressed sheets of high-carbon ferrochrome samples. The measurement results are corrected by introducing carbon content, ultimately yielding a method for characterizing chromium content. By establishing a correction formula between carbon and chromium content, the pressed sheet method is elevated from traditional qualitative / semi-quantitative analysis to quantitative detection.

[0021] 2. The method of the present invention solves the problem of poor accuracy caused by sample inhomogeneity and matrix interference in the tablet compression method, expands the scope of application of the method, and makes it a substitute for time-consuming high-precision detection methods in rapid screening scenarios.

[0022] 3. While retaining the advantages of the tableting method in terms of "simple sample preparation and rapid response", the method of the present invention eliminates the complicated pretreatment steps of traditional quantitative methods (such as wet digestion and spectral depth analysis), significantly improving detection efficiency and making it more suitable for production rhythm requirements.

[0023] 4. The method of this invention can significantly shorten the detection process and improve detection efficiency while ensuring data accuracy. Rapidly fed-back detection data supports real-time adjustment of smelting process parameters, reducing production delays caused by waiting for test results. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0025] Example 1:

[0026] A rapid method for determining the chromium content in high-carbon ferrochrome includes the following steps:

[0027] 1) High-carbon ferrochrome alloy is crushed and then passed through a 140-mesh sieve to obtain high-carbon ferrochrome powder;

[0028] 2) Boric acid powder is used as a base, and the obtained high carbon ferrochrome powder is spread on top. The powder is then pressed by a tablet press at a pressure of 32 MPa for 33 seconds to obtain a pressed thin sheet sample.

[0029] 3) The thin-section sample obtained in step 2) was analyzed using a qualitative and semi-quantitative method with fluorescence spectroscopy to obtain the total elemental mass percentage content (S) obtained by the qualitative and semi-quantitative method. UQ The uncorrected mass percentage of chromium was 92.61% (C). Cr0 62.20%;

[0030] 4) The carbon content (C C 10.15% (detected using the method specified in GB / T 4699.4-2008 "Determination of Carbon Content in Ferrochrome and Silicon-Chromium Alloys - Infrared Absorption Method and Gravimetric Method") was introduced, and then expressed by formula C. Cr =C Cr0 ×100% / (C) C +S UQ The final chromium content (C) is calculated and corrected to obtain the result. Cr The value was 60.53%. A comparison with the wet method test results (the results of the test in GB / T 4699.2-2008 "Determination of Chromium Content in Ferrochromium-Silicon-Chromium Alloys - Ammonium Persulfate Oxidation Titration and Potentiometric Titration") is shown in Table 1.

[0031] Example 2:

[0032] A rapid method for determining the chromium content in high-carbon ferrochrome includes the following steps:

[0033] 1) High-carbon ferrochrome alloy is crushed and passed through a 150-mesh sieve to obtain high-carbon ferrochrome powder;

[0034] 2) Boric acid powder is used as a base, and high carbon ferrochrome powder is spread on top. The powder is then pressed by a tablet press at a pressure of 33 MPa for 35 seconds to obtain a pressed sheet sample.

[0035] 3) The thin-section sample obtained in step 2) was analyzed using a qualitative and semi-quantitative method with fluorescence spectroscopy to obtain the total elemental mass percentage content (S) obtained by the qualitative and semi-quantitative method. UQ The content of chromium was 91.85% and the uncorrected mass percentage of chromium (C). Cr0 61.58%;

[0036] 4) The percentage of carbon by mass (C) C ) 11.52% introduced, C C The detection method is the same as in Example 1, using formula C. Cr =C Cr0 ×100% / (C) C +S UQ The final chromium content (C) was calculated and corrected to obtain the mass percentage of chromium. Cr The value was 59.57%. A comparison with the wet method test results (the results of the method specified in GB / T 4699.2-2008 "Determination of Chromium Content in Ferrochromium-Silicon-Chromium Alloys - Ammonium Persulfate Oxidation Titration and Potentiometric Titration") is shown in Table 1.

[0037] Example 3:

[0038] A rapid method for determining the chromium content in high-carbon ferrochrome includes the following steps:

[0039] 1) High-carbon ferrochrome alloy is crushed and passed through a 160-mesh sieve to obtain high-carbon ferrochrome powder;

[0040] 2) Boric acid powder is used as a base, and high carbon ferrochrome powder obtained in step one is spread on top. The powder is then pressed using a tablet press at a pressure of 36 MPa for 42 seconds to obtain a pressed sheet sample.

[0041] 3) The thin-section sample obtained in step two was analyzed using a qualitative and semi-quantitative method with fluorescence spectroscopy to obtain the total elemental mass percentage content (S0) obtained by the qualitative and semi-quantitative method. UQ The content of chromium was 95.66% and the uncorrected mass percentage of chromium (C). Cr0 65.78%;

[0042] 4) The percentage of carbon by mass (C) C 6.40% introduced, C C The detection method is the same as in Example 1, using formula C. Cr =C Cr0 ×100% / (C) C +S UQ The final chromium content (C) was calculated and corrected to obtain the mass percentage result. Cr The value was 64.45%. A comparison with the wet method test results (see Table 1 for the method described in GB / T 4699.2-2008 "Determination of Chromium Content in Ferrochromium-Silicon-Chromium Alloys - Ammonium Persulfate Oxidation Titration and Potentiometric Titration") is shown in Table 1.

[0043] Example 4:

[0044] A rapid method for determining the chromium content in high-carbon ferrochrome. It includes the following steps:

[0045] 1) High-carbon ferrochrome alloy is crushed and then passed through a 180-mesh sieve to obtain high-carbon ferrochrome powder;

[0046] 2) Boric acid powder is used as a base, and high carbon ferrochrome powder obtained in step 1) is spread on top. The powder is then pressed using a tablet press at a pressure of 39 MPa for 55 seconds to obtain a pressed sheet sample.

[0047] 3) The thin-section sample obtained in step two was analyzed using a qualitative and semi-quantitative method with fluorescence spectroscopy to obtain the total elemental mass percentage content (S0) obtained by the qualitative and semi-quantitative method. UQ The uncorrected mass percentage of chromium was 94.21% (C). Cr0 56.79%;

[0048] 4) The percentage of carbon by mass (C) C 8.22% introduced, C C The detection method is the same as in Example 1, using formula C. Cr =C Cr0 ×100% / (C) C +S UQ The final chromium content (C) was calculated and corrected to obtain the mass percentage of chromium. Cr The chromium content was 55.44%. A comparison with the wet method test results (see Table 1 for the method described in GB / T 4699.2-2008 "Determination of Chromium Content in Ferrochromium-Silicon-Chromium Alloys - Ammonium Persulfate Oxidation Titration and Potentiometric Titration") is shown in Table 1.

[0049] Table 1. Comparison of chromium content by mass percentage (%) between the results of the example assay and the wet method.

[0050]

[0051] This invention significantly shortens the testing process and improves testing efficiency while ensuring data accuracy. The rapid feedback of testing data supports real-time adjustments to smelting process parameters, reducing production delays caused by waiting for test results.

Claims

1. A method for rapidly determining the chromium content of high-carbon ferrochromium, characterized in that, The method comprises the following steps: 1) high-carbon ferrochrome alloy is crushed and sieved to obtain high-carbon ferrochrome powder; 2) a thin slice sample is prepared by using boric acid powder as a base and the high-carbon ferrochrome powder obtained in step 1) is laid thereon and then pressed by a tablet press; 3) the thin slice sample obtained in step 2) is analyzed by using a qualitative semi-quantitative method in a fluorescence spectrometer to obtain the total mass percentage of elements and the uncorrected mass percentage of chromium element; 4) the content of chromium element is calculated: C Cr =C Cr0 ×100% / (C C +S UQ ); wherein: C Cr is the mass percent content of chromium; C C is the mass percent content of carbon; C Cr0 is the uncorrected mass percent content of chromium; S UQ is the sum of the mass percent contents of the elements.

2. The method for rapidly determining the chromium content in high-carbon ferrochrome according to claim 1, characterized in that, The high-carbon ferrochrome alloy in step 1) is crushed and sieved through a 120-200 mesh sieve.

3. The method for rapidly determining the chromium content in high-carbon chromium iron according to claim 1, characterized in that, The content of carbon element in step 4) is measured by using any existing national standard or industry standard.

4. The method for rapidly determining the chromium content in high-carbon chromium iron according to claim 1, characterized in that, The pressing pressure of the tablet press in step 2) is 30-40 MPa, and the time is 30-60 seconds.

5. The method for rapidly determining the chromium content in high-carbon chromium iron according to claim 1, characterized in that, The thin slice sample obtained in step 2) is stored in a desiccator.

6. The method for rapidly determining the chromium content in high-carbon chromium iron according to claim 1, characterized in that, In step 2), the boric acid powder is an analytical reagent; and the thickness of the high-carbon ferrochrome powder is more than 1 mm.

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