Fusion casting glass sheet method for rapidly determining potassium, sodium, silicon, calcium, magnesium, aluminum, titanium, sulfur and phosphorus in coal ash

Abstract

The invention belongs to the technical field of chemical analysis, and particularly discloses a casting glass sheet method for quickly measuring potassium, sodium, silicon, calcium, magnesium, aluminum, titanium, sulfur and phosphorus in coal ash, which comprises the following steps: 1) preparing a sample casting glass sheet: putting a coal ash sample, anhydrous lithium tetraborate and lithium carbonate into a platinum crucible, uniformly mixing, dropwise adding an ammonium bromide solution, and stirring for 20-30 minutes; placing in an automatic sample melting machine to prepare a fuse piece, cooling, drying and storing for detection; and 2) XRF detection: constructing a standard working curve on an X-ray fluorescence spectrometer, and respectively testing the contents of potassium, sodium, silicon, calcium, magnesium, aluminum, titanium, sulfur and phosphorus in the sample casting glass sheet prepared in the step 1) by using the standard working curve. According to the method, borate high-temperature melting is adopted, so that the granularity effect, the mineral effect and the nonuniformity of the sample can be effectively eliminated, meanwhile, the absorption and enhancement effects among sample elements are well reduced, and the analysis precision and accuracy are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical analysis, and in particular relates to a fused glass sheet method for rapidly determining potassium, sodium, silicon, calcium, magnesium, aluminum, titanium, sulfur and phosphorus in coal ash. Background Art

[0002] The influence of coal ash composition on the thermal properties of coking coal and coke comes from the catalytic properties of the coal ash composition itself, but on the other hand, the coal ash composition partially reflects the influence of the deposition environment on the properties of coking coal. Coal ash composition refers to various metal and non-metal oxides and salts generated by the combustion of minerals in coal. The main components are SiO2, Al2O3, Fe2O3, CaO, MgO, TiO2, P2O5, K2O, Na2O, etc. The influence of coal ash composition on coke is very important, but it is often overlooked. The ash content of coking coal does not soften, melt, or shrink during coking, which can reduce the cohesiveness of coal, increase coke cracks, and reduce the crushing strength and wear resistance of coke. Some studies and production practices have shown that the fundamental reason for the deterioration of blast furnace permeability and liquid permeability is the pulverization of coke in the lower part of the blast furnace. The main reason for the pulverization of coke in the blast furnace is the carbon dissolution reaction between coke and CO2. The presence of alkali metals and alkaline earth metals in the ash component of coke (coking coal) will accelerate the carbon dissolution reaction of coke. The ash in coke (coking coal) contains more than ten kinds of minerals, which are generally expressed as oxides. Among them, K2O and Na2O (alkaline oxides) are strong and positive catalysts for the carbon dissolution reaction of coke; MgO, CaO, BaO (alkaline earth metals) and V2O5, MnO2, Fe2O3, CuO, ZnO (transition metals) are weak and positive catalysts; TiO2 and B2O3 are strong and negative catalysts, and Al2O3 and SiO2 have almost no effect on the carbon dissolution reaction of coke. Therefore, it is very important to detect the components in the ash of coal coke.

[0003] At present, as a relatively mature component analysis method, X-ray fluorescence spectrometer analysis is widely used in metallurgy, geology, environment, chemical industry, materials and other fields. The objects analyzed by X-ray fluorescence spectrometer are mainly bulk solids, powders and liquids. Among them, solid powders are the most analyzed. For example, cement, coal, dust, etc. are powders themselves. The detection and analysis of X-ray fluorescence by powder tableting is simple, fast and economical. It is widely used when the analysis workload is large and the analysis accuracy requirements are not too high. It is also often used for the analysis of trace elements. However, the XRF detection by tableting method is greatly affected by the matrix. Qualitative analysis can be satisfied, but accurate quantitative analysis is not ideal.

[0004] Therefore, how to quickly and accurately determine the composition of coal ash has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] In order to solve the drawbacks of the above-mentioned prior art, the present invention discloses a fused glass sheet method for rapidly determining potassium, sodium, silicon, calcium, magnesium, aluminum, titanium, sulfur and phosphorus in coal ash, which adopts the following technical means:

[0006] A fused glass sheet method for rapidly determining potassium, sodium, silicon, calcium, magnesium, aluminum, titanium, sulfur and phosphorus in coal ash comprises the following steps: 1) preparing a sample fused glass sheet: placing a coal ash sample, anhydrous lithium tetraborate and lithium carbonate in a platinum crucible, adding ammonium bromide solution dropwise after mixing, placing in an automatic melting machine to form a fused sheet, cooling, drying and storing for testing;

[0007] 2) XRF detection: Establish the corresponding measurement method on the X-ray fluorescence spectrometer, select the best measurement conditions for each component, correct the existing interference factors, calculate the regression to obtain the corresponding working curve, and then use the working curve to test the content of potassium, sodium, silicon, calcium, magnesium, aluminum, titanium, sulfur and phosphorus in the sample pieces.

[0008] Furthermore, in step 1), the mass ratio of the coal ash sample: anhydrous lithium tetraborate: lithium carbonate is 0.45-0.55: 7.0-8.0: 0.45-0.55.

[0009] Furthermore, in step 1), the concentration of the ammonium bromide solution is 0.4 g / mL, and the amount of the solution added is 10 to 15 drops.

[0010] Furthermore, in step 1), the specific steps of placing the sample in an automatic melting machine to form a fused sheet are as follows:

[0011] Place it in an automatic melting machine and melt it under the setting conditions of a melting temperature of 1000-1100°C, a static melting time of 2-4 minutes, a swing melting time of 8-10 minutes, a standing time of 0.5-1.5 minutes, and an air cooling time of 2-4 minutes after casting, and start the melting program to make a fused sheet.

[0012] Furthermore, the method further comprises the following steps: before preparing the sample molten glass sheet, drying the fly ash sample at a temperature of 105 to 110° C. for 1 to 2 hours, and storing the sample in a dry state before use.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] First, the present invention melts the coal ash to make a glass sheet, and uses X-ray fluorescence spectroscopy to quickly determine the content of potassium, sodium, silicon, calcium, magnesium, aluminum, titanium, sulfur, and phosphorus in the coal ash. The technology is innovative, and the measurement results are fast and accurate. Secondly, the present invention uses borate high-temperature melting, which can not only effectively eliminate the particle size effect, mineral effect and heterogeneity of the sample, but also greatly reduce the absorption and enhancement effect between the sample elements, thereby improving the precision and accuracy of the analysis. The present invention can directly measure elements with higher contents without diluting the test solution, which not only greatly saves detection time and personnel energy, but also can do more work to improve detection efficiency, and saves electricity and gas costs, reducing detection costs. It is an important innovation in the method for quickly and accurately determining the content of multiple harmful elements in coal ash, which can fill the gap in the domestic pretreatment of such samples, and has a very strong application prospect and great social benefits. DETAILED DESCRIPTION

[0015] The technical solution of the present invention is clearly and completely described below in conjunction with specific embodiments. It should be pointed out that the embodiments described below are intended to facilitate the understanding of the present invention and do not have any limiting effect.

[0016] The lithium tetraborate, lithium carbonate and ammonium bromide used in the examples of the present invention are all common commercial products, and lithium tetraborate and lithium carbonate are analytically pure. Coal ash 1# (GBW(E)110099), coal ash 2# (GBW(E)110100), coal ash 3# (GBW(E)110101) and coal ash 4# (GBW(E)110102) were purchased from Shandong Metallurgical Science Research Institute.

[0017] The instruments and models used in the embodiments of the present invention are:

[0018] X-ray fluorescence spectrometer: ZSX Primus IV

[0019] Melting machine: HNJC-T4

[0020] Muffle furnace: AFD-8-10

[0021] Example 1

[0022] Accurately weigh 0.5000g of coal ash 1# (GBW(E)110099) sample, 7.5000g of anhydrous lithium tetraborate, and 0.5000g of lithium carbonate and add them to a platinum crucible in sequence, stir evenly, add 12 drops of 0.4g / mL ammonium bromide solution, place in an automatic melting machine with a melting temperature of 1050°C, a static melting time of 3 minutes, a swing melting time of 9 minutes, stand for 1 minute, and air cool for 3 minutes after casting as the setting conditions for melting, make a fused sheet on the melting program, cool and mark, and place in a dryer for testing. The test results are shown in Table 1.

[0023] Example 2

[0024] Accurately weigh 0.5000g of coal ash 2# (GBW(E)110100) sample, 7.5000g of anhydrous lithium tetraborate, and 0.5000g of lithium carbonate and add them into a platinum crucible in sequence, stir evenly, add 12 drops of 0.4g / ml ammonium bromide solution, place in an automatic melting machine with melting temperature of 1050℃, static melting time of 3 minutes, swing melting time of 9 minutes, stand for 1 minute, air cooling for 3 minutes after casting as setting conditions for melting, make fused sheets on the melting program, cool and mark, place in a dryer for testing. The test results are shown in Table 1.

[0025] Example 3

[0026] Accurately weigh 0.5000g of coal ash 3# (GBW(E)110101) sample, 7.5000g of anhydrous lithium tetraborate, and 0.5000g of lithium carbonate and add them to a platinum crucible in sequence, stir evenly, add 12 drops of 0.4g / mL ammonium bromide solution, place in an automatic melting machine with a melting temperature of 1050℃, a static melting time of 3 minutes, a swing melting time of 9 minutes, stand for 1 minute, and air cool for 3 minutes after casting as the setting conditions for melting, make a fused sheet on the melting program, cool and mark, and place in a dryer for testing. The test results are shown in Table 1.

[0027] Example 4

[0028] Accurately weigh 0.5000g of coal ash 4# (GBW(E)110102) sample, 7.5000g of anhydrous lithium tetraborate, and 0.5000g of lithium carbonate and add them to a platinum crucible in sequence, stir evenly, add 12 drops of 0.4g / mL ammonium bromide solution, place in an automatic melting machine with a melting temperature of 1050℃, a static melting time of 3 minutes, a swing melting time of 9 minutes, stand for 1 minute, and air cool for 3 minutes after casting as the setting conditions for melting, make a fused sheet on the melting program, cool and mark, and place in a dryer for testing. The test results are shown in Table 1.

[0029] Table 1 Test results of various embodiments

[0030]

[0031]

[0032] Table 2 Actual values ​​of coal ash 1#~4#

[0033]

[0034] From Table 1 and Table 2, it can be seen that the detection method of the present invention has high detection accuracy.

Claims

1. A fused glass sheet method for rapid determination of potassium, sodium, silicon, calcium, magnesium, aluminum, titanium, sulfur and phosphorus in coal ash, characterized in that: The steps include: 1) Preparation of sample casting glass sheet: Place fly ash sample, anhydrous lithium tetraborate and lithium carbonate in a platinum crucible, mix well and then drop ammonium bromide solution, place in an automatic melting machine to make a fused sheet, cool, dry and store for testing; 2) XRF detection: A standard working curve is constructed on an X-ray fluorescence spectrometer, and the contents of potassium, sodium, silicon, calcium, magnesium, aluminum, titanium, sulfur and phosphorus in the sample molten glass sheet prepared in step 1) are tested using the standard working curve.

2. The method of molten glass sheet according to claim 1, characterized in that: In step 1), the mass ratio of the coal ash sample: anhydrous lithium tetraborate: lithium carbonate is 0.45-0.55: 7.0-8.0: 0.45-0.

55.

3. The fused glass sheet method according to claim 1, characterized in that: In step 1), the concentration of the ammonium bromide solution is 0.4 g / mL, and the amount of the solution added is 10 to 15 drops.

4. The method of fused glass sheet casting according to claim 1, characterized in that: In step 1), the specific steps of placing the sample in an automatic melting machine to make a fused sheet are as follows: Place it in an automatic melting machine and melt it under the setting conditions of a melting temperature of 1000-1100°C, a static melting time of 2-4 minutes, a swing melting time of 8-10 minutes, a standing time of 0.5-1.5 minutes, and an air cooling time of 2-4 minutes after casting, and start the melting program to make a fused sheet.

5. The method of fused glass sheet casting according to claim 1, characterized in that: The following steps are also included: Before preparing the sample casting glass sheet, the fly ash sample was dried at 105-110°C for 1-2 hours and stored dry before use.

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