At present, high-zircon bricks are mainly used in the construction of glass melting furnaces, and their quality affects the service life of glass melting furnaces. The main components of high-zircon bricks are zircon , silica and alumina. The chemical properties of high-zircon bricks are inactive. , Various acids are difficult to dissolve, and it is more difficult to analyze. At present, there is no high-efficiency and rapid detection method that is matched with it.
At present, the determination methods of zircon , silica and alumina specified in the 2007 national standard "GBT 4981-2007" are commonly used to determine the content of the main components in high zirconium bricks. The determination method in the national standard is: the zircon content is determined by the phenylhydroxyacetic acid gravimetric method, the silica content is determined by the molybdenum blue photometric method, and the alumina content is determined by the chrome azurol S photometric method. Disadvantages of the method: (1) The method is complicated; (2) It is not easy to operate; (3) The test time is long, and many steps are prone to errors.
This article introduces an invention. The purpose of the invention is to overcome the above-mentioned shortcomings in the prior art and provide a method for determining the content of main components in high zirconium bricks, which can efficiently and accurately determine the oxidation of main components in high zirconium bricks. The weight percentage content of zirconium, silica and alumina.
Specific operation:
(1) Mixing different weights of zircon , silica and alumina to obtain a mixture, dissolving the mixture as a solute in a solvent, and fusing samples to obtain multiple standard samples;
(2) Measure the fluorescence intensity of multiple standard samples obtained in step (1), and establish a standard curve between the weight percentage content of zircon , the weight percentage content of silica, the weight percentage content of alumina and the fluorescence intensity respectively;
(3) Dissolve the high zirconium brick to be tested as a solute in a solvent, melt the sample to obtain the sample to be tested, measure the fluorescence intensity of the sample to be tested, and determine the high zircon brick to be tested according to the standard curve obtained in step (2) The weight percentage content of zircon , silica and alumina.
Precautions:
1. In step (1), the method for obtaining the mixture includes: before mixing, burning, cooling, and drying the zircon , silica and alumina, and then drying the dried zircon , silica and oxide Aluminum is mixed; preferably, the burning conditions include: a temperature of 800-1000° C., and a time of 0.5-2 h.
2. In step (1), based on the weight of the mixture, the content of zircon is 90-98%, the content of silica is 0.5-6%, and the content of alumina is 1-8%.
3. In step (1), the number of the multiple standard samples is at least 5, preferably 5-8.
4. In step (1) and step (3), the solvent is lithium tetraborate and/or lithium metaborate, preferably a mixture of lithium tetraborate and lithium metaborate; the weight ratio of solute to solvent is both 0.05 -0.1:1
5. In step (1) and step (3), the method of melting sample preparation includes: adding ammonia iodide to the mixture of solute and solvent, and treating at 1000-1150°C for 0.25-0.5h; solute The weight ratio to ammonia iodide is 1:0.1-0.15.
6. In step (3), the method of dissolving the high zirconium brick to be measured in a solvent includes: first grinding the high zirconium brick to be measured into a powder, and drying it, and then dissolving the product obtained by the drying treatment in the solvent The conditions of the drying treatment include: the drying temperature is 80-300°C, and the drying time is 0.5-3h.
7. In order to reduce errors, improve precision and accuracy. The purity levels of the zirconium oxide, silicon dioxide, aluminum oxide, lithium tetraborate and lithium metaborate are analytically pure or superior-grade pure grades, preferably superior-grade pure grades.
8. In step (2) and step (3), use a fluorescence spectrometer to measure the fluorescence intensity.
9. Use an electronic balance with an absolute accuracy of 0.1 mg to weigh each component.
Examples:
1. Put premium-grade pure zircon , premium-grade pure silica, and premium-grade pure alumina into clean platinum crucibles, burn them in a muffle furnace at 1000℃ for 1h, take them out and cool them at 25℃ 5min, then transfer to the weighing bottle and cover the bottle cap, put it in a desiccator to dry for 20min, set aside;
2. As shown in Table 1, weigh and mix the superior-grade pure zircon , superior-grade pure silica, and superior-grade pure alumina obtained in step (1) to obtain a mixture, and the aforementioned mixtures are respectively dissolved in the superior grade as solutes In the mixed solvent of grade pure lithium metaborate and superior grade pure lithium tetraborate, add 20wt% ammonia iodide solution and melt it at 1150°C for 0.35 hours to obtain 5 standard samples;
Table 1
3. Measure the fluorescence intensity of the five standard samples obtained in step (2) by using a fluorescence spectrometer. The intensity is the ordinate, and the standard curve between the weight percentage content of zircon and the fluorescence intensity, the weight percentage content of silica and the fluorescence intensity, the weight percentage content of alumina and the fluorescence intensity is established. The standard curves are respectively: y = 3.87755102x1+10.5430781, y=2.1777778x2-0.9333333, y=0.54285714x3-1.0285714, x1 is the weight percentage content of zircon , x2 is the weight percentage content of silica, x3 is The weight percentage content of alumina, y is the fluorescence intensity;
4. Grind the high zirconium brick to be tested into powder (with a particle size below 45um), and dry it at 110°C for 2h, then dissolve the product obtained by 0.6g as a solute in 6g premium-grade pure lithium metaborate And premium grade pure lithium tetraborate mixed solvent (the weight ratio of the two is 1:2.03), and then add 20wt% ammonia iodide solution, and melt it at 1150℃ for 0.35h to obtain the sample to be tested. The weight ratio of dry product to ammonia iodide is 1:0.15;
5. Measure the fluorescence intensity of the sample to be tested obtained in step (4) with a fluorescence spectrometer, and determine the weight of zircon , silica and alumina in the high zircon brick to be tested according to the corresponding standard curve obtained in step (3) The percentage content, wherein the determined weight percentage content of zircon is 96.78%, the weight percentage content of silica is 2.12%, and the weight percentage content of alumina is 1.06%.
6. Accuracy analysis
The standard recovery rate is used to evaluate the accuracy of the method: where, in steps (4)-(5), the standard addition treatment is carried out, the addition amount of zircon is 1.00wt%, and the addition amount of silica is 0. 50wt%, the amount of alumina added is 0.20wt%, the spiked product is dried at 110°C for 2h, and then 0.6g of the dried product is dissolved as a solute in 6g of superior grade pure lithium metaborate and excellent Grade pure lithium tetraborate mixed solvent (the weight ratio of the two is 1: 2.03), and then add 20wt% ammonia iodide solution, and melt it at 1150℃ for 0.35h to obtain the sample to be tested. Among them, the dried product The weight ratio to ammonia iodide is 1:0.15; the fluorescence intensity is measured by a fluorescence spectrometer, and the weight percentage content of zirconium oxide, silicon dioxide and aluminum oxide to be measured is determined according to the corresponding standard curve obtained in step (3). Among them, the results of the standard addition recovery rate are shown in Table 2.
Table 2
It can be seen from the results in Table 2 that the recovery rate of standard addition is between 98.4% and 100.03%, indicating that the accuracy of the method of the present invention is very high.
7. Precision analysis
Repeat step (4) to obtain 11 samples to be tested. Use a fluorescence spectrometer to measure the fluorescence intensity respectively, according to the steps(3) The obtained corresponding standard curve determines the weight percentage content of zircon , silica and alumina in the high zircon brick to be tested. Among them, the measurement result of the zircon content is shown in Table 3, the measurement result of the silica content is shown in Table 4, and the measurement result of the alumina content is shown in Table 5.
Table 3
Table 4
Table 5
From the results in Table 3 to Table 5, it can be seen that 11 parallel analyses are performed on the same sample, and the relative deviations of the weight percentage content of zircon , silica and alumina determined by the method of the present invention are all ≤ 2.0%, which indicates that The invented method has good dispersion, high precision and high credibility.
Advantage
The method of the present invention has the advantages of short time, high recovery rate of standard addition, and high reliability of the result. It can efficiently, quickly and accurately determine the weight percentage content of the main components of zircon , silica and alumina in high zircon bricks. The research on the composition of zirconium bricks and the quality control of high zirconium bricks have important guiding significance.
