Method for detecting antiknock property of silica

Abstract

The invention provides a method for detecting the anti-knock property of silica. The detection method comprises the following steps: performing high-temperature treatment on a silica sample to be detected in a sealed state; performing a drum test on the cooled silica sample to be detected to obtain silica particles; the silica particles are sieved, target silica particles are obtained, and the particle size of the target silica particles is larger than 20 mm; calculating the anti-explosion rate of the silica to be detected according to the total mass of the silica sample to be detected and the total mass of the target silica particles; the high-temperature treatment comprises the following steps: heating from room temperature to 1400-1600 DEG C at a heating rate of 5-10 DEG C / min, and keeping the temperature for 28-32 minutes. The detection method has the advantages of being matched with actual working conditions, high in safety, high in repeatability and the like.

Description

Technical Field

[0001] This application relates to the field of industrial silicon testing technology, and in particular to a method for testing the explosion resistance of silica. Background Technology

[0002] In the industrial silicon smelting process, silica is the main raw material, and its explosion resistance (i.e., its ability to resist high temperatures and mechanical impacts from exploding and breaking) directly affects the furnace charge resistance, heat zone distribution, smelting efficiency, and energy consumption. Silica with poor explosion resistance is easily broken into powder in the furnace, leading to charge adhesion, lower resistance, and electrode lifting, causing frequent "sparking" phenomena. This not only increases the amount of SiO gas escaping and the yield of microsilica powder, and reduces silicon recovery rate, but also disrupts the reaction balance in the furnace, increasing non-production time and maintenance costs such as no-load operation, idle firing, and furnace cleaning.

[0003] Traditional methods for testing the blast resistance of silica have drawbacks, including low relevance to actual working conditions, failure to consider mechanical effects, and potential safety risks. Furthermore, there is currently a lack of unified testing standards for silica blast resistance within the industry. Therefore, traditional methods for testing the blast resistance of silica still require improvement. Summary of the Invention

[0004] Based on this, one or more embodiments of this application provide a method for testing the explosion resistance of silica that is consistent with actual working conditions, has high safety and good repeatability.

[0005] According to a first aspect of the embodiments of this application, a method for testing the explosion resistance of silica is provided, comprising the following steps:

[0006] The silica sample to be tested was subjected to high-temperature treatment under sealed conditions.

[0007] A drum test was performed on the cooled silica sample to obtain silica particles.

[0008] Obtain target silica particles with a particle size greater than 20 mm;

[0009] The explosion resistance rate of the silica sample to be tested is calculated based on the total mass of the silica sample to be tested and the total mass of the target silica particles.

[0010] The high-temperature treatment includes the following steps: heating from room temperature to 1400℃~1600℃ at a heating rate of 5℃ / min~10℃ / min, and holding at that temperature for 28min~32min.

[0011] In some embodiments, the high-temperature treatment includes the following steps: heating from room temperature to 1000°C at a heating rate of 9°C / min to 10°C / min, and then heating from 1000°C to 1400°C to 1600°C at a heating rate of 5°C / min to 6°C / min.

[0012] In some embodiments, before the silica sample to be tested is subjected to high-temperature treatment, the following step is also included: crushing the silica sample to be tested.

[0013] In some embodiments, the particle size of the silica sample to be tested after crushing is 60 mm to 100 mm.

[0014] In some embodiments, after the silica sample to be tested is crushed and before the high-temperature treatment, the following steps are also included: the silica sample to be tested is sequentially cleaned and dried.

[0015] In some embodiments, the drum test includes the following steps: placing the cooled silica sample to be tested into the drum device and rotating it at a rate of 38 r / min to 42 r / min for 1.5 min to 2.5 min.

[0016] In some embodiments, the total mass of the silica sample to be tested is m, the total mass of the target silica particles is m1, and the explosion resistance rate of the silica sample to be tested is λ, where λ = m1 / m × 100%.

[0017] In some embodiments, obtaining the target silica particles includes the following steps: sieving the silica particles using a 20mm sieve.

[0018] In some of these embodiments, the total mass of the silica sample to be tested is not less than 1000g.

[0019] In some embodiments, a silicon molybdenum rod box furnace is used to perform high-temperature treatment on the silica sample to be tested.

[0020] Compared with traditional technologies, this application has the following advantages:

[0021] The explosion-proof testing method for silica disclosed in this application simulates the actual temperature change process of silica in a submerged arc furnace from room temperature to a specific temperature at a specific heating rate. Furthermore, it eliminates the need to open the furnace door to add samples at high temperatures, thus improving operational safety. By conducting a drum test on the silica sample, the mechanical actions of silica during furnace feeding, tamping, collapse within the furnace, and mutual collisions and friction during movement can be simulated, providing a more comprehensive assessment of silica's explosion-proof properties. In addition, the testing method of this application reduces errors caused by human operation through reasonable control of each step, thereby improving the repeatability and accuracy of the testing method. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the specific embodiments of this application, the drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0023] Figure 1 This is a flowchart illustrating a method for testing the explosion resistance of silica according to one embodiment of this application. Detailed Implementation

[0024] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, a detailed description of specific embodiments of this application is provided. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise specifically stated, all raw materials, reagents, instruments, and equipment used in this application are commercially available or can be prepared by existing methods.

[0026] The terms "and / or," "or / and," and "and / or" as used herein include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes technical solutions connected by "logical AND," and also undoubtedly includes technical solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, a technical solution that is connected by "logical OR"), as well as any and all combinations of A, B, C, and D, that is, combinations of any two or three of A, B, C, and D, and also combinations of all four of A, B, C, and D (that is, a technical solution that is connected by "logical AND").

[0027] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0028] The terms “combinations of,” “any combination of,” and “any combination of” used in this article include all suitable combinations of any two or more of the listed items.

[0029] In this document, the term "suitable" as used in phrases such as "suitable combination," "suitable method," and "any suitable method" refers to the ability to implement the technical solution of this application, solve the technical problem of this application, and achieve the expected technical effect of this application.

[0030] In this application, terms such as "further," "even further," and "particularly" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0031] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0032] In this application, numerical intervals (i.e., numerical ranges) are involved. Unless otherwise specified, the selected numerical distributions within the aforementioned numerical intervals are considered continuous and include the two endpoints (i.e., the minimum and maximum values) of the numerical range, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints. In this document, this is equivalent to directly listing every integer. For example, if t is an integer selected from 1 to 10, it means that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Furthermore, when multiple ranges are provided to describe features or characteristics, these ranges can be merged. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0033] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0034] Traditional methods use rapid heating and cooling to test silica samples, which can cause random cracks on the sample surface, resulting in large deviations and poor repeatability in the overall test results. Furthermore, traditional testing methods only test the changes caused by rapid cooling and completely ignore mechanical effects such as collisions in actual working conditions, leading to an inflated explosion resistance index that is out of touch with production realities. In addition, traditional methods rely on manual sieving, introducing uncontrollable human error.

[0035] Some embodiments of this application provide a method for testing the explosion resistance of silica, comprising the following steps:

[0036] The silica sample to be tested was subjected to high-temperature treatment under sealed conditions.

[0037] A drum test was performed on the cooled silica sample to obtain silica particles.

[0038] Obtain target silica particles, wherein the particle size of the target silica particles is greater than 20 mm;

[0039] The explosion resistance rate of the silica sample to be tested is calculated based on the total mass of the silica sample to be tested and the total mass of the target silica particles.

[0040] The high-temperature treatment includes the following steps: heating from room temperature to 1400℃~1600℃ at a heating rate of 5℃ / min~10℃ / min, and holding at that temperature for 28min~32min.

[0041] The explosion-proof testing method for silica disclosed in this application simulates the actual temperature change process of silica in a submerged arc furnace from room temperature to a specific temperature at a specific heating rate. Furthermore, it eliminates the need to open the furnace door to add samples at high temperatures, thus improving operational safety. By conducting a drum test on the silica sample, the mechanical actions of silica during furnace feeding, tamping, collapse within the furnace, and mutual collisions and friction during movement can be simulated, providing a more comprehensive assessment of silica's explosion-proof properties. In addition, the testing method of this application reduces errors caused by human operation through reasonable control of each step, thereby improving the repeatability and accuracy of the testing method.

[0042] It is understandable that in the industrial silicon production process, the minimum particle size requirement for silica raw materials is 20mm. Therefore, this application can better reflect the explosion resistance of silica by obtaining silica particles with a particle size of 20mm or more and weighing them.

[0043] Figure 1 This is a flowchart illustrating a method for testing the explosion-proof performance of silica according to one embodiment of this application.

[0044] As an example, in the high-temperature treatment step, the heating rate can be 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min, 10℃ / min, or any value within the range formed by any two of the above points.

[0045] As an example, in the high-temperature treatment step, the highest temperature can be 1400℃, 1410℃, 1420℃, 1430℃, 1440℃, 1450℃, 1460℃, 1470℃, 1480℃, 1490℃, 1500℃, 1510℃, 1520℃, 1530℃, 1540℃, 1550℃, 1560℃, 1570℃, 1580℃, 1590℃, 1600℃, or any value within the range formed by any two of the above points.

[0046] As an example, in the high-temperature treatment step, the holding time at the highest temperature can be 28 min, 29 min, 30 min, 31 min, or 32 min, or any value within the range formed by any two of the above points.

[0047] Furthermore, the high-temperature treatment includes the following steps: heating from room temperature to 1400℃ at a heating rate of 5℃ / min to 10℃ / min, and holding at that temperature for 30 minutes.

[0048] Understandably, this application's method of gradually and steadily heating from room temperature to 1400°C effectively simulates the actual temperature change process of silica in a submerged arc furnace from initial feeding to entering the high-temperature reaction zone. Furthermore, the set temperature of 1400°C is closer to the actual reaction temperature and melting point of silica, allowing the explosion resistance test results to more closely resemble actual production conditions.

[0049] In actual production, the holding time set in the furnace charging operation cycle is generally 30 minutes. Therefore, keeping silica at high temperature for 30 minutes can make the test results more in line with actual production and fully examine its thermal stability at this temperature.

[0050] The drum test can simulate the mechanical effects of silicon during furnace loading, tamping, and the collapse and movement of materials in the furnace, such as mutual collisions and friction, and comprehensively evaluate its mechanical strength retention rate under high temperature conditions, making the testing dimensions more comprehensive.

[0051] The method described in this application eliminates the need to open the furnace door at high temperatures, reducing the risk of damage to heating components and burns to personnel.

[0052] In some embodiments, the high-temperature treatment includes the following steps: heating from room temperature to 1000°C at a heating rate of 9°C / min to 10°C / min, and then heating from 1000°C to 1400°C to 1600°C at a heating rate of 5°C / min to 6°C / min.

[0053] In some embodiments, before the silica sample to be tested is subjected to high-temperature treatment, the following step is also included: crushing the silica sample to be tested.

[0054] In some embodiments, the particle size of the silica sample to be tested after crushing is 60 mm to 100 mm.

[0055] As an example, the particle size of the silica sample to be tested can be 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm, or any value within the range formed by any two of the above points.

[0056] It is understandable that crushing the silica sample to be tested into the above-mentioned specific particle size range can form a more stable and porous material layer structure and promote the uniform upward transmission of heat in the lower reaction zone. Furthermore, the silica sample with uniform particle size can reduce the "sintering and caking" caused by fine powder filling the pores and maintain the stability of the furnace charge resistance, thereby helping to maintain the stability of the current path in the furnace and enabling the electrical energy to be efficiently converted into reaction heat.

[0057] In some embodiments, after the silica sample to be tested is crushed and before the high-temperature treatment, the following steps are also included: the silica sample to be tested is sequentially cleaned and dried.

[0058] In some embodiments, the drum test includes the following steps: placing the cooled silica sample to be tested into the drum device and rotating it at a rate of 38 r / min to 42 r / min for 1.5 min to 2.5 min.

[0059] Furthermore, the drum test includes the following steps: the cooled silica block is placed in the drum device and rotated at a rate of 40 r / min for 2 min.

[0060] In some embodiments, the total mass of the silica sample to be tested is m, the total mass of the target silica particles is m1, and the explosion resistance rate of the silica sample to be tested is λ, where λ = m1 / m × 100%.

[0061] In some specific examples, the silica sample to be tested was measured at least three times, and the calculated average value was taken as the result of the explosion resistance calculation.

[0062] In some embodiments, obtaining the target silica particles includes the following steps: sieving the silica particles using a 20mm standard sieve.

[0063] In some of these embodiments, the total mass of the silica sample to be tested is not less than 1000g.

[0064] In some embodiments, a silicon molybdenum rod box furnace is used to perform high-temperature treatment on the silica sample to be tested.

[0065] The aforementioned testing method of this application accurately simulates the actual thermal history of silica in a submerged arc furnace through orderly heating and high-temperature holding steps. Furthermore, by introducing a drum test, it achieves a comprehensive performance evaluation of the silica's thermal stress and the mechanical effects of impact. This testing method not only eliminates the safety risks of high-temperature furnace opening but also ensures high repeatability and reliability of the test results due to its standardized control throughout the entire process.

[0066] The present application will be further described below with reference to specific embodiments and comparative examples, but these should not be construed as limiting the scope of protection of the present application. Unless otherwise specified, the raw materials involved in the following specific embodiments are all commercially available, the instruments used are all commercially available, and the processes involved are conventionally selected by those skilled in the art unless otherwise specified.

[0067] Example 1

[0068] (1) Sample preparation: Take a total mass of m of silica sample to be tested. After composition analysis and particle size sieving, take silica blocks with a particle size of 60 mm to 100 mm, and clean and dry them. The data results of silica samples that meet the composition analysis by mass percentage are shown in Table 1.

[0069] Table 1

[0070]

[0071] (2) Place the silica block sample into a sealed silicon molybdenum rod high-temperature furnace and heat it from room temperature to 1000℃ at a heating rate of 10℃ / min, and then heat it from 1000℃ to 1400℃ at a heating rate of 5℃ / min, and hold it for 30min.

[0072] (3) Cooling: After the heat preservation is completed, the sample is cooled to room temperature with the furnace.

[0073] (4) Drum test: Place the cooled sample in the drum tester and rotate it at 40 r / min for 2 minutes.

[0074] (5) Sieving and weighing: The sample after the drum test was sieved using a 20mm standard sieve, and the weight of the material on the sieve was measured as m1.

[0075] (6) Calculate the explosion resistance rate: Calculate the explosion resistance rate λ based on the weight of the material on the sieve and the initial weight of the sample. The calculation formula is as follows: explosion resistance rate λ = m1 / m × 100%.

[0076] Each batch of samples was measured three times, and the average value was taken.

[0077] Five different batches of silica samples were tested using the method described above, and the results are shown in Table 2.

[0078] Table 2

[0079]

[0080] As shown in the table above, silica 1 has an average explosion resistance of 99.82% (average pulverization rate of 0.18%), with excellent data parallelism, indicating that its mineral structure is dense and uniform, and its thermal stability is excellent, meaning that it will hardly crack. The high consistency of the three experimental data indicates that the ore source has a very uniform and stable texture, making it an ideal raw material for submerged arc furnace smelting. Silica 2 has an average explosion resistance of 97.96% (average pulverization rate of 2.04%). Its explosion resistance meets the basic requirements of industrial production, and its low pulverization tendency has little impact on furnace conditions in actual production, making it suitable as a stable raw material. Silica 3 has an average explosion resistance of 47.23% (average pulverization rate of 52.77%), meaning that more than half of the silica entering the furnace will turn into powder. Silica with poor explosion resistance is prone to pulverizing in the furnace, increasing non-production time and maintenance costs such as no-load operation, sintering, and furnace cleaning. It also leads to charge adhesion, lower resistance, electrode elevation, and alters the furnace's thermal balance, increasing the frequency of "sparking" phenomena. This not only increases SiO gas escape and microsilica powder production and reduces silicon recovery, but also severely disrupts the furnace reaction balance, causing a sharp increase in energy consumption. Such silica should be prohibited from direct feeding into the furnace under normal circumstances. Silica 4 and silica 5 have average explosion resistance of 86.80% and 86.44% respectively (average pulverization rate of approximately 13.5%), showing highly similar performance. This means that using this silica in the furnace will result in over one-tenth of the material pulverizing, easily triggering "sparking" phenomena, causing electrode elevation, affecting furnace conditions, and increasing power consumption. Strict ore blending and process parameter adjustments are necessary when using this silica.

[0081] In summary, from the perspective of blast resistance, silica 1 exhibits excellent blast resistance and is a high-quality raw material for industrial silicon production; silica 2 is good and can be used normally; silica 4 and 5 have slightly lower blast resistance than silica 1 and 2, but still meet the blast resistance standards for furnace-loaded silica, and their use should be controlled; silica 3's blast resistance is below the minimum standard for furnace-loaded silica, and its use in the furnace is not recommended. When screening silica raw materials, an entry standard based on blast resistance data should be established, with silica 1 given priority; silica 2 can be used as a reliable supplement; risk management and adjustments to the blending of ore for silica 4 and 5 are required; silica 3 should be prohibited from direct use.

[0082] Comparative Example 1

[0083] (1) Sample preparation: Take a silica sample with a total mass of m, and after crushing, take silica blocks with a particle size of 60mm~100mm, and clean and dry them.

[0084] (2) Place the silica block into a silicon carbide rod box furnace that has been kept at a constant temperature of 1350°C and heat it rapidly for 15 minutes. Then allow the sample to cool to room temperature with the furnace.

[0085] (3) Use a 20mm standard sieve to sieve the cooled sample and weigh the weight of the material on the sieve, m1; calculate the explosion resistance rate λ by combining the weight of the material on the sieve with the initial weight of the sample. The calculation formula is as follows: explosion resistance rate λ = m1 / m × 100%.

[0086] Each batch of samples was measured three times, and the average value was taken.

[0087] The explosion resistance of silica 3 and silica 4 in Example 1 was tested according to the method of Comparative Example 1, and the results are shown in Table 3.

[0088] Table 3

[0089]

[0090] As shown in the table above, the results obtained from three repeated tests of silica 3 and silica 4 using the method of Comparative Example 1 generally differed significantly, indicating that the repeatability of the test results using this method is poor. Furthermore, in actual operation, human error was easily observed during the silica sieving process. Moreover, the average values ​​of the results measured by Comparative Example 1 for silica 3 and silica 4 were 52.98% and 91.24%, respectively, both higher than the results measured in Example 1; these may deviate significantly from the actual results.

[0091] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0092] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for detecting the shatter resistance of silica, characterized by, The method comprises the following steps: high-temperature treatment is performed on the to-be-tested silica sample in a sealed state; a drum test is performed on the cooled to-be-tested silica sample to obtain silica particles; target silica particles with a particle size greater than 20 mm are obtained; the anti-burst rate of the to-be-tested silica sample is calculated according to the total mass of the to-be-tested silica sample and the total mass of the target silica particles; the high-temperature treatment comprises the following steps: heating from room temperature to 1400-1600 ℃ at a heating rate of 5-10 ℃ / min, and keeping the temperature for 28-32 min.

2. The method of claim 1, wherein the high-temperature treatment comprises the following steps: heating from room temperature to 1000 ℃ at a heating rate of 9-10 ℃ / min, and then heating from 1000 ℃ to 1400-1600 ℃ at a heating rate of 5-6 ℃ / min.

3. The method of claim 1, wherein Before the high-temperature treatment is performed on the to-be-tested silica sample, the method further comprises the following step: performing crushing treatment on the to-be-tested silica sample.

4. The method of claim 3, wherein the method is characterized by The particle size of the to-be-tested silica sample after the crushing treatment is 60-100 mm.

5. The method of claim 3, wherein the method is characterized by: After the crushing treatment is performed on the to-be-tested silica sample, before the high-temperature treatment, the method further comprises the following steps: sequentially performing cleaning treatment and drying treatment on the to-be-tested silica sample.

6. The method of testing the shatter resistance of silica according to any one of claims 1 to 5, wherein the drum test comprises the following steps: placing the cooled to-be-tested silica sample into a drum test device, and rotating at a speed of 38-42 r / min for 1.5-2.5 min.

7. The method according to any one of claims 1 to 5, wherein The total mass of the to-be-tested silica sample is m, the total mass of the target silica particles is m1, and the anti-burst rate of the to-be-tested silica sample is λ, wherein λ=m1 / m×100%.

8. The method according to any one of claims 1 to 5, wherein The target silica particles are obtained by screening the silica particles with a 20-mm sieve.

9. The method according to any one of claims 1 to 5, wherein The total mass of the to-be-tested silica sample is not less than 1000 g.

10. The method of testing the shatter resistance of silica according to any one of claims 1 to 5, wherein The high-temperature treatment is performed on the to-be-tested silica sample by using a silicon-molybdenum rod box-type electric furnace.

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