Method for analyzing refractory material through rapid glass melting method-inductively coupled plasma atomic emission spectrometry

Abstract

The invention discloses a method for analyzing a refractory material by a rapid glass melting method-inductively coupled plasma atomic emission spectrometry, which comprises the following steps of: preparing a lithium tetraborate-lithium metaborate protective film in a platinum yellow crucible, preparing a standard quality control sample into a molten glass sheet, and dissolving into a to-be-tested solution; determining the content of components in the quality control sample by inductively coupled plasma atomic emission spectrometry, and drawing a working curve; and then measuring the component content in the refractory material sample to be measured, and measuring data by using the same processes of manufacturing the melt sheet, dissolving the melt sheet, filtering the sample to be measured and using the inductively coupled plasma atomic emission spectrometry. According to the method, the rapid analysis of SiO2, Al2O3, CaO, Fe2O3, TiO2, K2O, MnO, MgO, P2O5, Na2O, Cr2O3 and ZrO2 in the refractory material can be completed at the same time, and the detection time is shortened.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of raw material analysis, and particularly relates to an analysis method of refractory materials. BACKGROUND

[0002] Refractory materials refer to inorganic non-metallic materials with a refractoriness of not less than 1580 DEG C, and the ability to resist high-temperature sudden changes and slag erosion and withstand high-temperature loads. The definition of refractory materials is not only based on its refractoriness, but also involves its physical and chemical properties at high temperatures. The main function of refractory materials is to maintain structural stability in high-temperature environments, resist thermal shock, chemical corrosion and mechanical wear. They are widely used in steel metallurgy, building materials, chemical industry, power industry and other industrial fields as the base materials of high-temperature equipment and structures.

[0003] According to the chemical composition, mineral composition, manufacturing process and use characteristics, refractory materials can be divided into several categories, each of which has its unique application scenarios and advantages. According to the chemical composition, it can be divided into siliceous refractory materials, aluminosilicate refractory materials, magnesia refractory materials, carbon refractory materials, zirconium refractory materials, etc.

[0004] The existing or reported methods for detecting the main elements in refractory materials mainly include single-element analysis, such as gravimetric method, oxidation-reduction method and spectrophotometric method. However, these methods need to determine the content of each component one by one, which is complex in operation, long in detection period, difficult in pretreatment, and difficult to meet the requirements of batch rapid detection in actual production. The industry has always hoped to use a more rapid sample digestion method to replace traditional wet operation with instrument analysis. Inductively coupled plasma atomic emission spectrometry, as a modern detection method, has the characteristics of simple operation, fast analysis speed, wide analysis range, high precision, and can simultaneously determine multiple elements, and is widely used in the detection of various materials in the metallurgical industry. At present, the sample digestion of refractory materials mainly adopts alkali fusion method, and the commonly used fluxes are sodium hydroxide, sodium peroxide and sodium carbonate. ① A large amount of flux (generally 6-12 times the amount of the sample) needs to be introduced during alkali fusion, which will cause great interference to the test; ② The introduction of too much sodium salt in refractory materials will cause the torch tube of ICP-AES to be blocked. ③ Due to the large number of types of refractory materials, direct high-temperature fusion of the sample without oxidation treatment will damage the platinum yellow pot.

[0005] Glass fusion method for dissolving samples is a detection method that does not introduce sodium salt, but glass fusion method cannot determine multiple elements at one time. Therefore, the use of glass fusion-melt inductively coupled plasma atomic emission spectrometry for the determination of each component in refractory materials can quickly and accurately analyze each component of refractory materials. There is no specific method reported for this test idea. SUMMARY

[0006] The application aims to provide a method for analyzing components in refractory materials by a rapid glass melting method-inductively coupled plasma atomic emission spectrometry, which can eliminate element interference by selecting optimal analysis spectral lines, and can meet detection requirements in precision and accuracy, i.e., can avoid the introduction of impurities and the loss of components in the traditional wet refractory material sample digestion process, and can meet the needs of rapid and accurate analysis of components in refractory materials.

[0007] To achieve the above-mentioned purposes, the technical solution adopted by the application is as follows: Step one, 10 portions of 4.000g lithium tetraborate-lithium metaborate mixed reagent are accurately weighed and placed in a Pt95%-Au5% crucible, heated in a muffle furnace at 800℃ for 20min, so that the lithium tetraborate-lithium metaborate forms a protective film in the Pt95%-Au5% crucible; after the crucible is cooled to room temperature, 0.1000g of standard quality control sample and 3.000g of lithium tetraborate-lithium metaborate mixed reagent are weighed and placed in a Pt95%-Au5% crucible, 10 drops of lithium nitrate (mass fraction 30%) solution and 4 drops of lithium bromide (mass fraction 30%) solution are added to each sample, pre-oxidized at 800℃ in a muffle furnace for 10min, cooled, and the platinum yellow crucible is moved into a high-frequency sample melting machine to melt the sample at 1050℃ for 20min, shaken for 10min, and the liquid is poured into a platinum yellow mold, cooled, and the fused sheet is taken out. The fused sheet sample is transferred to a 500mL beaker, and deionized water, hydrochloric acid and nitric acid in a volume ratio of 20:3:1 are added to dissolve the fused sheet at low temperature. After the solution is cooled, it is filtered with rapid filter paper, and diluted to 250mL in a volumetric flask. The solution is ready for ICP-AES determination.

[0008] Step two, the component content of the measured element is input in advance in the instrument analysis interface, the spectral line intensity of the measured element in the quality control sample obtained in step one is determined by an inductively coupled plasma atomic emission spectrometer (ICP-AES), and the component content of each quality control sample is used to select the optimal analysis spectral line. w The corresponding intensity I , the optimal analysis spectral line is selected, the calibration curve of the measured element is established, the first equation is obtained, the linearity of the calibration curve is checked by the linear correlation of the calibration curve, the correlation coefficient r is required to be greater than 0.999, and the working curve is drawn.

[0009] Step three, select the test sample, accurately take 4.000g lithium tetraborate-lithium metaborate mixed reagent and place it in a Pt95%-Au5% crucible, heat in a muffle furnace at 800 DEG C for 20min, so that lithium tetraborate-lithium metaborate forms a protective film in the Pt95%-Au5% crucible; after the crucible cools to room temperature, take 0.1000g test sample and 3.000g lithium tetraborate-lithium metaborate mixed reagent and place them in a Pt95%-Au5% crucible, drop 10 drops of lithium nitrate (mass fraction 30%) solution and 4 drops of lithium bromide (mass fraction 30%) solution on the sample, pre-oxidize in a muffle furnace at 800 DEG C for 10min, cool, move the platinum yellow crucible into a high-frequency sample melting machine, melt the sample at 1050 DEG C for 20min, shake for 10min, pour the liquid into a platinum yellow mold, cool, and take out the fused tablet. Transfer the fused tablet sample to a 500mL beaker, add 100mL secondary deionized water, 15mL hydrochloric acid and 5mL nitric acid, and dissolve the fused tablet at low temperature. After the solution cools, filter with rapid filter paper, dilute to 250mL in a volumetric flask, and determine the elements to be tested in the test sample by inductively coupled plasma atomic emission spectrometry.

[0010] The lithium tetraborate-lithium metaborate mixed reagent is analytical grade, ≥99.50%, the mass ratio of lithium tetraborate to lithium metaborate is 2:1, and the amount of the test sample is kept consistent with that used when preparing the calibration curve.

[0011] The particle size of the standard quality control sample in step one is required to be less than 0.125mm, the sample is dried before weighing, and is mixed uniformly with lithium tetraborate-lithium metaborate.

[0012] The instruments and equipment used in the above steps are as follows: a German Spex Spectro Blue full-spectrum direct-reading inductively coupled plasma atomic emission spectrometer and a DY511 type full-automatic multi-head high-frequency sample melting machine.

[0013] Inductively coupled plasma atomic emission spectrometry is a new type of analysis technology derived from atomic emission spectrometry. It has the advantages of wide linear range, high sensitivity and simple operation, can rapidly, low-cost and accurately simultaneously analyze multiple elements, and is an optimal instrument for determining the component content of refractory material samples.

[0014] The optimal pre-oxidation conditions are selected, typical samples are valued by multiple methods, similar refractory material standard samples with appropriate contents are selected, mixed standard samples are prepared by mixing, and a standard curve is established by adding standard solutions, so that the linear range covers the analysis range of conventional samples and is uniformly distributed in a gradient, the composition in the refractory material is rapidly detected, the test verification result is accurate and reliable, the result is consistent compared with the chemical method, and the refractory material existing detection and analysis and quality control requirements can be met.

[0015] The beneficial effects of the present application are as follows: (1) Using a mixture of lithium tetraborate and lithium metaborate as a solvent, melting the sample on a high-frequency sample melting machine, pouring into a mold, cooling and demolding to prepare uniform-sized molten glass pieces; then immersing the molten pieces in an acid solution to dissolve and acidify, forming a test solution. The quality control sample is determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), and a working curve is drawn. Then the content of elements in the unknown refractory material sample is determined. This method has the advantages of small matrix effect, no obvious interference between each measured element, and simple sample pretreatment operation. It can not only avoid the introduction of impurities and the loss of components in the traditional wet refractory material sample digestion process, but also meet the needs of rapid and accurate analysis of each component in refractory materials, and at the same time complete the analysis of SiO2, Al2O3, CaO, Fe2O3, TiO2, K2O, MnO, MgO, P2O5, Na2O, Cr2O3, ZrO2 in refractory materials, greatly improving the work efficiency and reducing the energy consumption, and having good application prospect and greater economic benefit.

[0016] (2) The method uses a mixture of lithium tetraborate and lithium metaborate as a flux to melt the sample on a high-frequency sample melting machine, avoiding the introduction of too much interfering flux, and not using sodium salt to melt the sample, which can avoid the torch pipe blockage of ICP-AES. Due to the special components of some refractory materials containing certain heavy metal elements, which are easy to form alloys with platinum and damage the platinum yellow crucible, lithium nitrate is used for pre-treatment of the sample to quickly analyze the sample.

[0017] (3) The present application uses a melting method to eliminate the mineral effect and particle size effect in the sample testing process, improve the accuracy of the method test, and expand the use range of the method. DETAILED DESCRIPTION

[0018] The present application will be further described in detail below in combination with the attached table and specific examples.

[0019] A rapid glass melting method for analyzing refractory materials by inductively coupled plasma atomic emission spectrometry, which comprises the following steps: Step one, accurately weigh 10 parts of 4.000 g lithium tetraborate-lithium metaborate mixed reagent into Pt95%-Au5% crucible, heat in 800°C muffle furnace for 20 min, so that lithium tetraborate-lithium metaborate forms a protective film in Pt95%-Au5% crucible; after the crucible cools to room temperature, weigh 0.1000 g of standard quality control sample and 3.000 g of lithium tetraborate-lithium metaborate mixed reagent into Pt95%-Au5% crucible, add 10 drops of lithium nitrate (30%) solution and 4 drops of lithium bromide (30%) solution to each sample, pre-oxidize in 800°C muffle furnace for 10 min, cool, move the platinum yellow crucible into the high-frequency sample fusion machine to melt the sample at 1050°C for 20 min, shake for 10 min, pour the liquid into a platinum yellow mold, cool, and take out the fusion sheet. Transfer the fusion sheet sample to a 500 mL beaker, add 100 mL of secondary deionized water, 15 mL of hydrochloric acid and 5 mL of nitric acid, and dissolve the fusion sheet at low temperature. After the solution cools, filter with rapid filter paper, dilute to 250 mL in a volumetric flask, and determine the measured elements in the test sample by ICP-AES.

[0020] Step two, input the component content of the measured elements in advance in the instrument analysis interface, and determine the spectral line intensity of the measured elements in the quality control sample obtained in step one by ICP-AES; select the optimal element spectral line according to the component content of each quality control sample ( w ) and the corresponding intensity ( I ), establish the calibration curve of the measured elements, obtain the linear equation, check the linearity of the calibration curve through the linear correlation of the calibration curve, and the correlation coefficient r is required to be >0.999, and draw the working curve.

[0021] Step three, select the test sample, accurately weigh 4.000 g of lithium tetraborate-lithium metaborate mixed reagent into Pt95%-Au5% crucible, heat in 800°C muffle furnace for 20 min, so that lithium tetraborate-lithium metaborate forms a protective film in Pt95%-Au5% crucible; after the crucible cools to room temperature, weigh 0.1000 g of the test sample and 3.000 g of lithium tetraborate-lithium metaborate mixed reagent into Pt95%-Au5% crucible, add 10 drops of lithium nitrate (30%) solution and 4 drops of lithium bromide (30%) solution to the sample, pre-oxidize in 800°C muffle furnace for 10 min, cool, move the platinum yellow crucible into the high-frequency sample fusion machine to melt the sample at 1050°C for 20 min, shake for 10 min, pour the liquid into a platinum yellow mold, cool, and take out the fusion sheet. Transfer the fusion sheet sample to a 500 mL beaker, add 100 mL of secondary deionized water, 15 mL of hydrochloric acid and 5 mL of nitric acid, and dissolve the fusion sheet at low temperature. After the solution cools, filter with rapid filter paper, dilute to 250 mL in a volumetric flask, and determine the measured elements in the test sample by ICP-AES.

[0022] Table 1 content of each component in 10 refractory quality control samples Table 2 the best element spectrum line corresponding to each component determined by inductively coupled plasma atomic emission spectrometer The linear equation of each component of the refractory is as follows, the linear correlation coefficient of all analysis components is greater than 0.999, meeting the analysis requirements, as shown in Table 3.

[0023] Table 3 linear equation of each component of the refractory The mixed flux is a mixture of lithium tetraborate and lithium metaborate, and the mass ratio is 2:1, and the amount of 0.1g of the sample to be tested corresponding to the lithium tetraborate-lithium metaborate mixed reagent is 3g.

[0024] The high-frequency melting machine melts the liquid, which needs to be poured into a platinum yellow mold, cooled, and the fused sheet is taken out, and then the fused sheet is dissolved in acid. If the red-hot molten liquid is directly poured into the acid, the reaction is violent, and spattering is easy to form, which is easy to cause the loss of the sample solution, and the preparation of the fused glass sheet with consistent size can greatly reduce the system error.

[0025] The acid solution for dissolving the fused sheet is a mixed acid of hydrochloric acid and nitric acid (the concentration of the laboratory bottled concentrated hydrochloric acid and concentrated nitric acid), and the volume ratio of deionized water, hydrochloric acid and nitric acid is 20:3:1. The glass sheet is dissolved quickly, and the instrument measurement process has less interference.

[0026] In order to verify the accuracy of the method, three refractory samples are selected to verify the accuracy of the method, as shown in Table 4, and the accuracy of the experimental data is good by comparing the chemical method and the method, and the results meet the national standard tolerance requirements.

[0027] Table 4 comparison of experimental data of chemical method and the method At the same time, in order to verify the precision of the method, the same sample is detected for 10 times. As shown in Table 5, the relative standard deviation of the component content in the refractory is small, which shows that the method is stable and reliable.

[0028] Table 5 data precision detection of multiple tests of the same sample In summary, the application first prepares 10 refractory material quality control samples and a sample to be tested into molten glass pieces, then immerses the molten pieces into a mixed acid solution of nitric acid and hydrochloric acid with a certain volume ratio to be dissolved at low temperature, and obtains a test solution.

[0029] Although the specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and such a description manner is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A method for analyzing refractory materials using a rapid glass melting method-inductively coupled plasma atomic emission spectrometry (ICP-AES), characterized in that, Includes the following steps: Step 1: Accurately weigh 10 portions of 4.000g lithium tetraborate-lithium metaborate mixed reagent and place them in a Pt 95%-Au 5% crucible. Heat in a muffle furnace at 800℃ for 20 minutes to form a protective film of lithium tetraborate-lithium metaborate in the Pt 95%-Au 5% crucible. After the crucible cools to room temperature, weigh 0.1000g of standard quality control sample and 3.000g of lithium tetraborate-lithium metaborate mixed reagent and place them in a Pt 95%-Au 5% crucible. Add 10 drops of 30% lithium nitrate solution to each sample. Pre-oxidize the sample in a muffle furnace at 800℃ for 10 min with 4 drops of 30% lithium bromide solution. After cooling, transfer the platinum crucible to a high-frequency melting machine and melt the sample at 1050℃ for 20 min. Shake for 10 min, pour the liquid into a platinum mold, cool, remove the fused sample, transfer the fused sample to a 500 mL beaker, add deionized water, hydrochloric acid, and nitric acid in a volume ratio of 20:3:1, dissolve the fused sample at low temperature, and after the solution cools, filter it with rapid filter paper and dilute to 250 mL in a volumetric flask for ICP-AES determination. Step 2: Input the component content of the element to be measured into the instrument analysis interface beforehand, and use an inductively coupled plasma atomic emission spectrometer to measure the spectral intensity of the analyte in the quality control samples obtained in Step 1; then use the component content of each quality control sample... w and the corresponding strength I Select the optimal spectral line for analysis, establish the calibration curve for the element to be measured, obtain the linear equation, check the linearity of the calibration curve through the linear correlation of the calibration curve, the correlation coefficient r should be >0.999, and plot the working curve. Step 3: Select the test sample and prepare a lithium tetraborate-lithium metaborate protective film on the Pt95%-Au5% crucible as in Step 1. After the crucible cools to room temperature, weigh 0.1000g of the test sample and 3.000g of the lithium tetraborate-lithium metaborate mixed reagent into the Pt95%-Au5% crucible. Prepare a fusion sheet, dissolve the fusion sheet, filter, and dilute to a volume of 250mL in a volumetric flask. Use an inductively coupled plasma atomic emission spectrometer to determine the analytes in the test sample.

2. The method for analyzing refractory materials using a rapid glass melting method-inductively coupled plasma atomic emission spectrometry according to claim 1, characterized in that: In steps one and three, the lithium tetraborate-lithium metaborate mixed reagent is of analytical grade, ≥99.50%, and the mass ratio of lithium tetraborate to lithium metaborate is 2:

1. The amount of the test sample is kept consistent with the amount used when preparing the calibration curve.

3. The method for analyzing refractory materials using a rapid glass melting method-inductively coupled plasma atomic emission spectrometry according to claim 1, characterized in that: In step one, the standard quality control sample particle size is required to be less than 0.125 mm. The sample should be dried before weighing and mixed evenly with lithium tetraborate-lithium metaborate.

Images