Method for detecting firing quality of calcined alpha alumina

Abstract

The invention relates to a method for detecting the firing quality of calcined alpha alumina, and belongs to the technical field of preparation of alpha alumina. The method comprises the following steps: obtaining standard color data of standard alpha alumina; the method comprises the following steps: carrying out first dyeing on a to-be-detected alpha alumina sample by using a first dyeing agent, washing, and standing the washed to-be-detected alpha alumina sample on filter paper to obtain a to-be-detected dyed sample; performing color identification on the to-be-detected dyed sample to obtain color data of the to-be-detected sample; and comparing the color data of the sample to be detected with the standard color data to complete the detection of the firing quality of the calcined alpha alumina. The method comprises the following steps: dyeing a to-be-detected alpha alumina sample to obtain color data of the to-be-detected sample, and comparing the color data with standard color data, so as to quickly judge the quality of the calcined alpha alumina. The method is easy to operate, low in input cost and low in requirement for the specialization degree of operators, can quickly provide reference for front-line production operators to master the firing quality, and has important significance in guiding the actual production process.

Description

Technical Field

[0001] The present application relates to the technical field of preparation of alpha alumina, and in particular to a method for detecting the sintering quality of calcined alpha alumina. Background Art

[0002] Calcined α alumina is widely used as raw material for ceramics, refractory materials and special glass, and a small amount is used in polishing, thermal conductivity and new energy materials. It has a large market demand and is widely used. It is generally produced by rotary kilns, tunnel kilns and other equipment, with alumina or aluminum hydroxide as raw materials. The firing temperature ranges from 1200-1500℃, which is related to the selection of mineralizers and quality requirements. The firing temperature and residence time are closely related to the firing quality. At present, the indicators used to evaluate the firing quality of calcined α alumina powder include α phase content, specific surface area, grain size, etc. In addition, ceramic shrinkage rate, firing density and other methods are often used to evaluate powder performance. The above detection methods are time-consuming and highly professional, which is not conducive to the continuous production detection of large equipment such as rotary kilns. The hysteresis of sample detection causes the lag of process adjustment, which may cause product quality fluctuations and is not conducive to actual production operations. Summary of the invention

[0003] The applicant discovered that calcined α alumina can absorb dyes. After the calcined α alumina is dyed with a dye, due to differences in the firing process, different calcined α aluminas have different specific surface areas, grain sizes, α conversion rates, etc., and the colors after dyeing are different in depth. By comparing with standard samples or normal products, the firing quality of the sample to be tested can be indirectly judged, which facilitates subsequent production adjustments and product selection.

[0004] The present application provides a method for detecting the sintering quality of calcined α alumina, which obtains color data of the sample to be tested by dyeing the sample to be tested, and compares the color data with standard color data, thereby quickly judging the quality of the calcined α alumina.

[0005] The present application provides a method for detecting the sintering quality of calcined alpha alumina, the method comprising:

[0006] Obtain standard color data of standard α-alumina;

[0007] The α-alumina sample to be tested is first dyed with a first dye, then washed, and the washed α-alumina sample to be tested is placed on filter paper and allowed to stand to obtain a dyed sample to be tested;

[0008] Performing color recognition on the dyed sample to be tested to obtain color data of the sample to be tested;

[0009] The color data of the sample to be tested is compared with the standard color data to complete the detection of the sintering quality of the calcined α alumina.

[0010] As an optional embodiment, the first stain includes Alizarin Red stain.

[0011] As an optional implementation manner, the mass of the α-alumina sample to be tested is 3g to 4g.

[0012] As an optional embodiment, the mass fraction of the first dye is 1.5‰ to 2.5‰; and / or

[0013] The volume usage of the first staining agent is 3mL to 6mL.

[0014] As an optional implementation, the first dyeing time is 4 minutes to 6 minutes.

[0015] As an optional embodiment, the washing is performed no less than 4 times.

[0016] As an optional implementation manner, the standing time is not less than 5 minutes.

[0017] As an optional implementation, the color identification method includes manual comparison and / or colorimeter detection.

[0018] As an optional embodiment, the method of obtaining the standard color data of standard alpha alumina includes:

[0019] Using a second dye to perform a second dyeing on the standard α alumina sample, then washing it, and placing the washed standard α alumina sample on filter paper to stand to obtain a standard dyed sample;

[0020] The standard dyeing sample is subjected to color recognition to obtain standard color data.

[0021] As an optional implementation, the process for obtaining the standard dyeing sample is the same as the process for obtaining the dyeing sample to be tested.

[0022] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0023] The method provided in the embodiment of the present application obtains color data of the sample to be tested by dyeing the sample to be tested, and compares it with the standard color data, thereby quickly judging the quality of the calcined alpha alumina. The method is simple to operate, has low investment cost, and does not require high professionalism of operators. It can quickly provide a reference for front-line production operators to grasp the sintering quality, which is of great significance for guiding the actual production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0026] Figure 1 A schematic diagram of a process for a method provided in an embodiment of the present application;

[0027] Figure 2 The photos of the samples in the test tubes at different washing times provided in the examples of the present application;

[0028] Figure 3 The photos of the dyed samples to be tested at different washing times provided in the embodiments of the present application;

[0029] Figure 4 This is a dyeing comparison chart of the alumina provided in the examples of the present application and different grades of calcined alpha alumina. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0031] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0032] The applicant found that calcined α-alumina can absorb dyes. After dyeing the calcined α-alumina with dyes, due to differences in the sintering process, different calcined α-alumina have different specific surface areas, grain sizes, α conversion rates, etc., and the colors after dyeing are different (e.g. Figure 4 By comparing with standard samples or normal products, the firing quality of the sample to be tested can be indirectly determined, which is convenient for subsequent production adjustments and product selection.

[0033] It should be noted that Figure 4 The product characteristics and dyeing results of different grades of calcined α alumina are shown in the following table:

[0034]

[0035] The present application intends to provide a method for quickly detecting the calcined α alumina sintering quality. Specifically, a dye is first prepared to dye the calcined α alumina raw powder to be tested, and the slurry after dyeing, washing and resting is poured onto the surface of filter paper. At this time, the alumina slurry presents a certain color due to the adsorption of the dye, and the color is affected by the slight differences in the sintering quality (specific surface area, grain size, α conversion rate, etc.) and presents different shades. At this time, the color data of the standard sample can be manually compared, or the L, a, b, c and other values ​​can be measured using a colorimeter, and then compared with the color data of the standard sample to find the difference.

[0036] Figure 1 A flow chart of the method provided in the embodiment of the present application is as follows: Figure 1 As shown, the embodiment of the present application provides a method for detecting the sintering quality of calcined α alumina, the method comprising:

[0037] S1. Obtain standard color data of standard α-alumina;

[0038] In some embodiments, obtaining standard color data of standard α alumina includes: S1.1. using a second dye to perform a second dyeing on the standard α alumina sample, then washing it, and placing the washed standard α alumina sample on filter paper to stand to obtain a standard dyed sample; S1.2. performing color identification on the standard dyed sample to obtain standard color data.

[0039] In some embodiments, the process of obtaining the standard stained sample is the same as the process of obtaining the stained sample to be tested.

[0040] S2. The α-alumina sample to be tested is first dyed with a first dye, and then washed, and the washed α-alumina sample to be tested is placed on filter paper and allowed to stand to obtain a dyed sample to be tested;

[0041] In some embodiments, the first staining agent includes Alizarin Red staining agent. After Alizarin Red staining agent stains α-alumina, the sample will appear pink.

[0042] In some embodiments, the mass of the α-alumina sample to be tested is 3 g to 4 g. For example, the mass of the α-alumina sample to be tested can be 3 g, 3.1 g, 3.2 g, 3.3 g, 3.4 g, 3.5 g, 3.6 g, 3.7 g, 3.8 g, 3.9 g or 4 g, etc., and can also be any value within the range of 3 g to 4 g.

[0043] In some embodiments, the mass fraction of the first dye is 1.5‰ to 2.5‰; the volume dosage of the first dye is 3mL to 6mL. Exemplarily, the mass fraction of the first dye can be 1.5‰, 1.6‰, 1.7‰, 1.8‰, 1.9‰, 2‰, 2.1‰, 2.2‰, 2.3‰, 2.4‰ or 2.5‰, etc., and it can also be any value in the range of 1.5‰ to 2.5‰. The volume dosage of the first dye can be 3mL, 3.5mL, 4mL, 4.5mL, 5mL, 5.5mL or 6mL, etc., and it can also be any value in the range of 3mL to 6mL.

[0044] In some embodiments, the first staining time is 4 min to 6 min. Exemplarily, the first staining time can be 4 min, 4.2 min, 4.4 min, 4.6 min, 4.8 min, 5 min, 5.2 min, 5.4 min, 5.6 min, 5.8 min or 6 min, etc., and can also be any value within the range of 4 min to 6 min.

[0045] In some embodiments, the number of washings is not less than 4. Exemplarily, the number of washings can be 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 times, etc., and can also be any value within the range of not less than 4 times.

[0046] In certain embodiments, the standing time is no less than 5min. Exemplary, the standing time can be 5min, 6min, 7min, 8min, 9min, 10min, 11min, 12min, 13min, 14min, 15min, 16min, 17min, 18min, 19min or 20min etc., and it can also be any value within the scope of no less than 5min. It should be noted that this standing process is mainly to reduce the influence of moisture in the dyeing sample to be measured on color recognition, and the selection of the standing time can be selected according to actual conditions.

[0047] S3. Performing color recognition on the dyed sample to be tested to obtain color data of the sample to be tested;

[0048] In some embodiments, the color recognition method includes manual comparison and / or colorimeter detection. The data detected by the colorimeter includes values ​​such as L, a, b, and c.

[0049] S4. Compare the color data of the sample to be tested with the standard color data to complete the detection of the sintering quality of the calcined α alumina.

[0050] This method obtains the color data of the α alumina sample to be tested by dyeing it, and compares it with the standard color data, thereby quickly judging the quality of the calcined α alumina. This method is simple to operate, has low investment costs, and does not require high professionalism of operators. It can quickly provide a reference for front-line production operators to grasp the sintering quality, which is of great significance for guiding the actual production process.

[0051] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.

[0052] Example 1

[0053] A sample of calcined alpha alumina AC-300MS was selected for staining test.

[0054] Staining test with different washing times:

[0055] Take 3g of sample, add the sample to a test tube, add 3ml of alizarin red dye, shake the test tube to mix the dye and sample thoroughly, let it stand for 5 minutes, pour out the upper dye solution, add 15g of distilled water to wash, shake and mix thoroughly, let it stand, pour out the upper solution, and compare the photos of the samples in the test tube after washing 1, 2, 3, and 4.5 times respectively. Figure 2 As shown, pour out the bottom sample and spread it evenly on the filter paper. The photos of the dyed samples to be tested after different washing times are shown in Figure 3 As shown, observe the color of the sample. After 10 minutes, wait for the water on the sample surface to disperse and use a colorimeter to measure the color value of the sample. The measured color value is as follows:

[0056]

[0057]

[0058] From the above table and the attached figures, it can be seen that after washing for more than 4 times, the chromaticity of the sample tends to be stable. L, a, b, and c change slightly. The number of washing times is selected to be 4 times.

[0059] Different dye dosage tests:

[0060] Take 3g of sample, add 1-6ml of Alizarin Red dye respectively, shake the test tube to mix the dye and sample thoroughly, let it stand for 5 minutes, pour out the upper dye solution, add 15g of distilled water for washing, shake it thoroughly, let it stand, pour out the upper solution, wash 4 times, pour out the bottom sample, evenly spread it on the filter paper, observe the color of the sample, wait for 10 minutes until the water on the sample surface is dispersed, and use a colorimeter to measure the sample color value. The measured color value is as follows:

[0061] Dyeing agent added ml L a b c 1 88.98 13.79 8.92 16.42 2 87.25 14.78 9.3 17.46 3 87.54 14.45 8.95 16.99 4 88.04 14.74 8.97 17.25 5 87.57 14.19 8.58 16.58 6 86.75 14.24 8.4 16.53

[0062] From the table above, we can see that the selected dye dosage is 4 ml. If too little dye is added, it cannot be shaken and mixed with the alumina powder; if too much dye is added, the color value will change greatly.

[0063] Staining tests with different sample amounts

[0064] Take 2-6g of sample, add 4ml of Alizarin Red dye, shake the test tube to mix the dye and sample thoroughly, let it stand for 5 minutes, pour out the upper dye solution, add 15g of distilled water for washing, shake and mix thoroughly, let it stand, pour out the upper solution, wash 4 times, pour out the bottom sample, evenly spread it on the filter paper, observe the color of the sample, wait for 10 minutes until the water on the sample surface is dispersed, and use a colorimeter to measure the sample color value. The measured color value is as follows:

[0065] Sample volume g L a b c 2 84.98 16.05 11.07 19.49 3 85.07 15.88 10.84 19.22 4 86.05 15.72 10.77 19.05 5 87.2 15.97 11.19 19.5 6 85.49 15.91 11.28 19.5

[0066] From the above table, we can see that the sample size is 3-4g.

[0067] Samples dyed and poured into filter paper, color test at different standing times

[0068] Take 3g of sample, add 4ml of Alizarin Red dye, shake the test tube to mix the dye and sample thoroughly, let it stand for 5 minutes, pour out the upper dye solution, add 15g of distilled water to wash, shake and mix thoroughly, let it stand, pour out the upper solution, wash 4 times, pour out the bottom sample, evenly spread it on the filter paper, observe the color of the sample, and measure the chromaticity value once every 1-30 minutes. The results are as follows:

[0069] Measurement time min L a b c 1 86.45 15.81 11.16 19.35 5 84.98 16.05 11.07 19.49 10 85.89 15.71 10.98 19.16 15 85.77 15.34 10.8 18.76 20 85.85 15.44 10.73 18.80 30 85.83 15.41 10.78 18.80 40 86.31 14.77 10.29 18 60 86.77 15.06 10.51 18.36

[0070] From the above table, we can see that the chromaticity of the sample changes little after 10 minutes. If the time is too short, the sample will be easily sticky to the lens of the colorimeter after being mixed with water.

[0071] In summary, for the quality inspection of calcined α-alumina AC-300MS samples, 3g of sample, 4ml of 2‰ Alizarin Red dye, each washing with distilled water for no less than 4 times, and the chromaticity value was measured after the sample was allowed to stand for 10 minutes were finally selected as the dyeing method.

[0072] However, in the actual production operation and testing process, the above method is not necessary. After multiple measurements, it was found that the amount of sample and dye does not need to be accurately weighed. When the number of washes is not less than 4 times, and the amount of water each time is sufficient to reach 2-3cm from the mouth of the test tube, the color and chromaticity value after dyeing are basically the same, with little change. It is faster and saves time.

[0073] It should be noted that, for quality inspection of samples of different types, the above process can be used to explore suitable preparation processes for the dyed samples to be tested, so as to achieve more accurate and rapid quality inspection.

[0074] In the actual production process, standard samples of a certain brand of product can be set for simultaneous dyeing comparison, or an allowable fluctuation range can be set for the chromaticity value as a means of quality monitoring.

[0075] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0076] In the present application, in the absence of any contrary description, the directional words used, such as "upper" and "lower", are specifically the directions of the drawings in the accompanying drawings. In addition, in the description of the present specification, the terms "including", "comprising", etc. refer to "including but not limited to". In this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. In this article, "and / or" describes the association relationship of the associated objects, indicating that there may be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone. Wherein A, B can be singular or plural. In this article, "at least one" refers to one or more, and "plural" refers to two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, "at least one of a, b or c", or "at least one of a, b and c", can both mean: a, b, c, ab (i.e. a and b), ac, bc, or abc, where a, b and c can be single or multiple.

[0077] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for detecting the sintering quality of calcined α-alumina, characterized in that: The method comprises: Obtain standard color data of standard α-alumina; The α-alumina sample to be tested is first dyed with a first dye, then washed, and the washed α-alumina sample to be tested is placed on filter paper and allowed to stand to obtain a dyed sample to be tested; Performing color recognition on the dyed sample to be tested to obtain color data of the sample to be tested; The color data of the sample to be tested is compared with the standard color data to complete the detection of the sintering quality of the calcined α alumina.

2. The method for detecting the sintering quality of calcined α-alumina according to claim 1, characterized in that: The first stain includes Alizarin Red stain.

3. The method for detecting the sintering quality of calcined α-alumina according to claim 1, characterized in that: The mass of the α-alumina sample to be tested is 3 g to 4 g.

4. The method for detecting the sintering quality of calcined α-alumina according to claim 1, characterized in that: The mass fraction of the first dye is 1.5‰ to 2.5‰; and / or The volume usage of the first staining agent is 3mL to 6mL.

5. The method for detecting the sintering quality of calcined α-alumina according to any one of claims 1 to 4, characterized in that: The first dyeing time is 4 minutes to 6 minutes.

6. The method for detecting the sintering quality of calcined α-alumina according to claim 1, characterized in that: The number of washing is no less than 4 times.

7. The method for detecting the sintering quality of calcined α-alumina according to claim 1, characterized in that: The standing time is not less than 5 minutes.

8. The method for detecting the sintering quality of calcined α-alumina according to claim 1, characterized in that: The color identification method includes manual comparison and / or colorimeter detection.

9. The method for detecting the sintering quality of calcined α-alumina according to claim 1, characterized in that: The standard color data of standard alpha alumina include: Using a second dye to perform a second dyeing on the standard α alumina sample, then washing it, and placing the washed standard α alumina sample on filter paper to stand to obtain a standard dyed sample; The standard dyeing sample is subjected to color recognition to obtain standard color data.

10. The method for detecting the sintering quality of calcined α-alumina according to claim 1, characterized in that: The process for obtaining the standard dyeing sample is the same as the process for obtaining the dyeing sample to be tested.

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