Method for determining unfired coal powder and coke powder in gas dust

Abstract

The invention discloses a method for determining unfired coal powder and coke powder in gas ash, which comprises the following steps: S1, selecting common injection anthracite, crushing the anthracite until the particle size is less than 3mm, drying for 24 hours, and removing moisture; s2, 100 g of anthracite powder in the step S1 is taken and put into a high-temperature-resistant cupel, and the temperature is increased to 900 DEG C under nitrogen protection; s3, making the powder treated in the step S2 into an unfired pulverized coal comparison image library; s4, selecting metallurgical coke, and crushing until the particle size is less than 5mm; s5, taking the coke powder in the step S4, and making a coke powder comparison image library; s6, blast furnace gas dust is taken as a sample to be made into a polished section, the polished section is compared with pictures of the unfired coal powder comparison picture library and the coke powder comparison picture library, and the proportion of the polished section and the unfired coal powder comparison picture library is determined. The method solves the problem that the organization forms of anthracite and coke are speculated by theory and experience after blast furnace combustion and melting loss, and no contrast gallery reference exists.

Description

Technical Field

[0001] This invention relates to the field of blast furnace ironmaking technology, and in particular to a method for determining unburned coal powder and coke powder in gas ash. Background Technology

[0002] Pulverized coal injection technology for blast furnaces is a groundbreaking technology in the history of blast furnace ironmaking. Its emergence and development are an important foundation and key link for maintaining the stability and sustainability of blast furnace ironmaking. At the current stage of blast furnace ironmaking development, increasing the amount of pulverized coal injection and reducing the amount of coke fed into the furnace are of great significance for reducing pig iron costs, improving hearth operating conditions, reducing pollution from coking production, and alleviating the shortage of high-quality coking coal resources.

[0003] However, excessive pulverized coal injection can affect pulverized coal combustion efficiency, coke replacement ratio, furnace permeability, and blast furnace stability. When the pulverized coal injection rate reaches a certain level, some pulverized coal that does not participate in the chemical reaction in the furnace will escape with the gas and eventually remain in the blast furnace ash. Analyzing the ratio of pulverized coal to coke in blast furnace gas ash is valuable for in-depth research on the utilization rate of pulverized coal under high pulverized coal injection conditions in blast furnaces.

[0004] Currently, the main methods for determining the ratio of pulverized coal to coke in blast furnace gas ash include petrographic microscopy, X-ray diffraction, and Raman spectroscopy. Among these, petrographic microscopy relies on the fact that coal and coke undergo different thermal evolution processes, resulting in different optical properties. Under a reflected light microscope, coke exhibits anisotropy and distinct optical structures, such as mosaic, flow, and lamellar structures; while unburned pulverized coal exhibits isotropy and a relatively uniform structure. By observing and statistically analyzing these structural characteristics, the ratio of pulverized coal to coke can be determined. However, these methods only infer the structural characteristics of unburned pulverized coal and coke based on the optical properties of coke and the microscopic features of coal, without considering the structural changes of coke and pulverized coal after combustion, reactions with various gases at high temperatures, and melting losses. Some components cannot be definitively identified as belonging to unburned pulverized coal or coke, thus limiting the accuracy of the results. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for determining unburned coal powder and coke powder in gas ash.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: A method for determining unburned coal powder and coke powder in gas ash includes the following steps: S1. Select commonly used pulverized anthracite, crush the anthracite to a particle size of less than 3 mm, then dry it in an oven at 105℃ for 24 hours to remove moisture, then grind it finely, and then sieve it using a 2 mm standard sieve to ensure that 85% of the particles are 2-1 mm. Collect the powder under the sieve for later use. S2. Select a high-temperature muffle furnace that can regulate the atmosphere. Take 100g of anthracite powder from step S1 and put it into a high-temperature resistant ash pan. First, heat it to 900℃ under nitrogen protection, then introduce compressed air for 10 minutes to simulate the combustion behavior of commonly injected anthracite in the combustion zone. Then, heat it to 1100℃ under carbon dioxide atmosphere, with the heating time controlled within half an hour, and then cool it to room temperature under nitrogen protection. S3. The powder processed in step S2 is made into a light slide. A 10x eyepiece and a 50x oil immersion lens are used to observe its morphology, extract characteristic images, and create a comparison library of unburned coal powder. S4. Select metallurgical coke, crush it to a particle size of less than 5mm, react it with carbon dioxide at 1100℃ for 2 hours, and then cool it to room temperature to obtain coke powder. Take the coke powder with a particle size of <1mm for later use. S5. Take the coke powder from step S4, make it into a light film, use a 10x eyepiece and a 50x oil immersion lens to observe its morphology, extract characteristic images, and make a coke powder comparison image library. S6. Take blast furnace gas ash as a sample, prepare a smooth film, use a 10x eyepiece and a 50x oil immersion lens to observe its morphology, and compare it with images in the unburned coal powder comparison image library and the coke powder comparison image library to determine its proportion.

[0007] In step S1, the industrial analysis results of the injected anthracite are: volatile matter 9-12%, ash content 10-13%, and fixed carbon 70-75%.

[0008] In step S1, a planetary ball mill is used for fine grinding.

[0009] The beneficial effects of this invention are: 1. In this invention, the combustion behavior and conditions of pulverized coal injected into a blast furnace are simulated. The anthracite is oxidized and burned in a high-temperature zone of 900°C for 10 minutes, and then slowly heated to 1100°C under a carbon dioxide atmosphere. The purpose is to investigate the melting loss of the anthracite by the gas.

[0010] 2. This invention solves the problem that the microstructure of anthracite and coke after combustion and melting in a blast furnace is inferred from theory and experience, without the need for comparative image libraries.

[0011] 3. This invention solves the problem of deviation in the determination of the proportion of unburned coal powder and coke powder in gas ash.

[0012] 4. This invention consists of steps such as the preparation of comparative samples, the construction of a comparative image library, and the measurement of samples. It can provide timely and accurate results in production and guide production operations. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the invention.

[0014] Example 1 A method for determining unburned coal powder and coke powder in gas ash includes the following steps: S1. Select commonly used pulverized anthracite, crush the anthracite to a particle size of less than 3 mm, then dry it in an oven at 105℃ for 24 hours to remove moisture, then grind it finely, and then sieve it using a 2 mm standard sieve to ensure that 85% of the particles are 2 mm. Collect the powder that passes through the sieve for later use. S2. Select a high-temperature muffle furnace that can regulate the atmosphere. Take 100g of anthracite powder from step S1 and put it into a high-temperature resistant ash pan. First, heat it to 900℃ under nitrogen protection, then introduce compressed air for 10 minutes to simulate the combustion behavior of commonly injected anthracite in the combustion zone. Then, heat it to 1100℃ under carbon dioxide atmosphere, with the heating time controlled within half an hour, and then cool it to room temperature under nitrogen protection. S3. The powder processed in step S2 is made into a light slide. A 10x eyepiece and a 50x oil immersion lens are used to observe its morphology, extract characteristic images, and create a comparison library of unburned coal powder. S4. Select metallurgical coke, crush it to a particle size of less than 5mm, react it with carbon dioxide at 1100℃ for 2 hours, and then cool it to room temperature to obtain coke powder. Take the coke powder with a particle size of <1mm for later use. S5. Take the coke powder from step S4, make it into a light film, use a 10x eyepiece and a 50x oil immersion lens to observe its morphology, extract characteristic images, and make a coke powder comparison image library. S6. Take blast furnace gas ash as a sample, prepare a smooth film, use a 10x eyepiece and a 50x oil immersion lens to observe its morphology, and compare it with images in the unburned coal powder comparison image library and the coke powder comparison image library to determine its proportion.

[0015] In step S1, the industrial analysis results of the injected anthracite are: volatile matter 9%, ash 10%, and fixed carbon 70%.

[0016] In step S1, a planetary ball mill is used for fine grinding.

[0017] Example 2 A method for determining unburned coal powder and coke powder in gas ash includes the following steps: S1. Select commonly used pulverized anthracite, crush the anthracite to a particle size of less than 3 mm, then dry it in an oven at 105℃ for 24 hours to remove moisture, then grind it finely, and then sieve it using a 2 mm standard sieve to ensure that 85% of the particles are 1 mm. Collect the powder that passes through the sieve for later use. S2. Select a high-temperature muffle furnace that can regulate the atmosphere. Take 100g of anthracite powder from step S1 and put it into a high-temperature resistant ash pan. First, heat it to 900℃ under nitrogen protection, then introduce compressed air for 10 minutes to simulate the combustion behavior of commonly injected anthracite in the combustion zone. Then, heat it to 1100℃ under carbon dioxide atmosphere, with the heating time controlled within half an hour, and then cool it to room temperature under nitrogen protection. S3. The powder processed in step S2 is made into a light slide. A 10x eyepiece and a 50x oil immersion lens are used to observe its morphology, extract characteristic images, and create a comparison library of unburned coal powder. S4. Select metallurgical coke, crush it to a particle size of less than 5mm, react it with carbon dioxide at 1100℃ for 2 hours, and then cool it to room temperature to obtain coke powder. Take the coke powder with a particle size of <1mm for later use. S5. Take the coke powder from step S4, make it into a light film, use a 10x eyepiece and a 50x oil immersion lens to observe its morphology, extract characteristic images, and make a coke powder comparison image library. S6. Take blast furnace gas ash as a sample, prepare a smooth film, use a 10x eyepiece and a 50x oil immersion lens to observe its morphology, and compare it with images in the unburned coal powder comparison image library and the coke powder comparison image library to determine its proportion.

[0018] In step S1, the industrial analysis results of the injected anthracite are: volatile matter 12%, ash 13%, and fixed carbon 75%.

[0019] In step S1, a planetary ball mill is used for fine grinding.

[0020] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A method for determining unburned coal powder and coke powder in gas ash, characterized in that, Includes the following steps: S1. Select commonly used pulverized anthracite, crush the anthracite to a particle size of less than 3 mm, then dry it in an oven at 105℃ for 24 hours to remove moisture, then grind it finely, and then sieve it using a 2 mm standard sieve to ensure that 85% of the particles are 2-1 mm. Collect the powder under the sieve for later use. S2. Select a high-temperature muffle furnace that can regulate the atmosphere. Take 100g of anthracite powder from step S1 and put it into a high-temperature resistant ash pan. First, heat it to 900℃ under nitrogen protection, then introduce compressed air for 10 minutes to simulate the combustion behavior of commonly injected anthracite in the combustion zone. Then, heat it to 1100℃ under carbon dioxide atmosphere, with the heating time controlled within half an hour, and then cool it to room temperature under nitrogen protection. S3. The powder processed in step S2 is made into a light slide. A 10x eyepiece and a 50x oil immersion lens are used to observe its morphology, extract characteristic images, and create a comparison library of unburned coal powder. S4. Select metallurgical coke, crush it to a particle size of less than 5mm, react it with carbon dioxide at 1100℃ for 2 hours, and then cool it to room temperature to obtain coke powder. Take the coke powder with a particle size of <1mm for later use. S5. Take the coke powder from step S4, make it into a light film, use a 10x eyepiece and a 50x oil immersion lens to observe its morphology, extract characteristic images, and make a coke powder comparison image library. S6. Take blast furnace gas ash as a sample, prepare a smooth film, use a 10x eyepiece and a 50x oil immersion lens to observe its morphology, and compare it with images in the unburned coal powder comparison image library and the coke powder comparison image library to determine its proportion.

2. The method for determining unburned coal powder and coke powder in gas ash according to claim 1, characterized in that, In step S1, the industrial analysis results of the injected anthracite are: volatile matter 9-12%, ash content 10-13%, and fixed carbon 70-75%.

3. The method for determining unburned coal powder and coke powder in gas ash according to claim 1, characterized in that, In step S1, a planetary ball mill is used for fine grinding.