A blended coal, coke and method of manufacture involving canadian coking coal having a plastic interval of < 60 degrees celsius

Abstract

This invention discloses a blended coal and coke, and a preparation method, using Canadian coking coal with a plasticity range <60℃, belonging to the field of coal blending and coking technology. It comprises 20%–24% gas coal, 4%–8% gas-rich coal, 3%–7% 1 / 3 coking coal, 9%–16% fat coal, and 25%–62% coking coal. The coking coal includes 5%–15% Canadian coking coal. The Canadian coking coal has a Kiel's flowability plasticity range of 50℃–55℃, a flowability MF of 11–37 PPM, a caking index G of 76–80, and a maximum plastic layer thickness Y of 14–18 mm. This invention replaces a portion of the coking coal with Russian fat coal in coal blending and coking, increasing its blending ratio and expanding the application range of coking coal, thus optimizing the utilization of imported coking coal resources.

Description

Technical Field

[0001] This invention belongs to the field of coal blending and coking technology, and more specifically, relates to a blended coal, coke, and preparation method of Canadian coking coal with a plasticity range of <60℃. Background Technology

[0002] Of the world's exploitable coking coal reserves, approximately half are located in Asia, one-quarter in North America, and the remaining quarter are scattered across other regions. In terms of proven coking coal reserves, my country accounts for about 25% of the world's total, giving it a comparative advantage. However, within my country's coking coal resources, low-rank, high-volatile gas coal and one-third coking coal constitute a relatively high proportion (45.73%); strongly caking coking coal accounts for 23.61%, ranking second; lean coal (including semi-lean coal) accounts for 15.89%; and strongly caking fat coal (including gas-fat coal) has the lowest proportion at 12.81%. In recent years, the exploitable reserves of high-quality coking coal (mainly coking coal and fat coal) in my country have been shrinking, and prices have continued to rise, especially with the increasingly tight supply of high-quality coking coal, a crucial type of coal for blending in coking. To expand coking coal resource channels and reduce blending costs, domestic coking enterprises are continuously increasing the proportion of imported coking coal in their blends. my country's imported coking coal mainly comes from countries such as Canada, Russia, Mongolia, and Australia. However, due to the different coal-forming environments in different regions, although the volatile matter and caking properties of coking coal meet the classification standards of domestic coking coal, their coking characteristics and geological properties have their own unique features, which to some extent restricts the efficient application of imported coking coal resources.

[0003] The literature "Research and Application of Canadian Raven Coking Coal in Meigang" states that the maximum proportion of Canadian coking coal in the blend is 9%. By stabilizing the proportion of fat coal and fine-tuning the proportions of gas coal, 1 / 3 coking coal, and lean coal, the quality indicators of coke are kept stable. However, the proportion of coking coal + fat coal in the coal blending structure has been increased from 55% to over 60%.

[0004] In daily production, using Canadian coking coal to replace domestic coking coal resulted in a decrease in the coke's shatter resistance strength (M40), and the coke quality could not meet the 3000m³ requirement. 3 The above blast furnaces meet stable production needs.

[0005] A search revealed that patent CN104232131A discloses a method for producing coke and coking using Canadian coking coal to improve the post-reaction strength (CSR) of the produced coke. It is produced by blending the following coals in the following mass percentages: 1 / 3 coking coal 10%–15%, gas coal 20%–28%, fat coal 20%–25%, coking coal 25%–35%, lean coal 5%–10%, and Canadian coking coal 5%–10%. The method utilizes the ash composition of the blended coal and substitute coal types to improve the stability of coke quality. Patent CN115044386A discloses a top-charge coking method using all imported coal, its products, and blended coal for coking. The top-charge coking coal blending method of the present invention uses the following mass percentage blending ratio to prepare the coking coal blend: 40%–60% imported coking coal, 20%–30% imported fat coal, 5%–15% imported 1 / 3 coking coal, and 10%–20% imported lean coking coal. The imported coking coal includes one or more of Australian coking coal, Mongolian coking coal, and Canadian coking coal, and the imported coking coal has a Vdaf content in the range of 20%–28%, a gluconate content (G) ≥ 80, and a coke coke CSR ≥ 60% when coked alone. Patent CN102851049A discloses a method for blending highly reactive coke, comprising blending coking coals, by weight percentage, comprising 10-40% gas coal, 10-30% 1 / 3 coking coal, 20-50% fat coal, 20-50% coking coal, and 5-15% a mixture of lean coal and iron ore powder, wherein the mixture of lean coal and iron ore powder comprises 50%-70% lean coal and 30%-50% iron ore powder by weight percentage. Alternatively, by weight percentage, the coking coals may comprise 25% Henan fat coal, 25% Canadian coking coal, 15% Shandong 1 / 3 coking coal, 25% Jiangsu gas coal, 5%-7% Shanxi lean coal, and 3%-5% iron ore powder. The cold strength index of the coke after coking is JIS drum DI. 150 15 (%)≥78, Mikum Drum M 25 (%)≥85, Mikum Drum M 10 (%)≤10. Among them, the Vdaf of Canadian coking coal is 25.4, G=88, and the maximum thickness of the plastic layer Y=14mm.

[0006] The Canadian coking coal mentioned in the above patents differs from the Canadian coking coal of this invention. The Canadian coking coal has a higher caking index G and is of higher quality. However, the coke made from Canadian coking coal with a lower caking index G cannot guarantee its shatter resistance. Summary of the Invention

[0007] 1. The problem to be solved

[0008] To address the issue of low shatter strength (M40) in coke produced by adding Canadian low-caking coking coal, this invention provides a blended coal containing Canadian coking coal with a plasticity range of <60℃. Coke produced using this blended coal has high shatter strength.

[0009] 2. Technical Solution

[0010] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0011] The mean random reflectance and distribution histogram of vitrinite, the plastic range of Gibbs flowability, the bonding index G, the maximum thickness of the plastic layer Y, and the mineral catalytic index MCI of Canadian coking coal were determined.

[0012]

[0013] The specific coal quality indicators of the Canadian coking coal with a plasticity range <60℃ are as follows: average maximum vitrinite reflectance Rran 1.20%–1.34%, Gibbs freeness plasticity range 50℃–55℃, freeness MF 11–37 PPM, caking index G 76–80, maximum plastic layer thickness Y 14–18 mm, mineral catalytic index MCI 1.5%–2.0%, dry ash-free volatile matter Vdaf 22%–25%, sulfur content St,d 0.30%–0.40%, dry ash content Ad 9.50%–10.50%, and coke CSR from a 40kg small coke oven: 73%–77%. This coal type belongs to coking coal according to Chinese coal classification, but the results from the 40kg test coke oven indicate that the coke has poor mechanical properties but good hot properties, unlike general domestic coking coal. Its plastic range is <60℃, resulting in a narrow temperature range and poor coal encapsulation. In daily production, when using Canadian coking coal to replace domestic coking coal, it leads to a decrease in the coke's shatter resistance strength (M40), and the coke quality cannot meet the 3000m³ requirement. 3 The above blast furnaces meet stable production needs.

[0014] Based on the random reflectance distribution of the vitrinite group of Canadian coking coal, such as Figure 1 As shown, a portion of this coal type falls into the category of coking coal, accounting for 34% to 37%. Therefore, this coal type can not only replace domestic coking coal, but also replace some coking coal, thereby reducing the impact on the quality of coal blending.

[0015] The coal is blended according to the following mass percentage composition: gas coal 20%–24%, gas-rich fat coal 4%–8%, 1 / 3 coking coal 3%–7%, and fat coal 1%–24%. # 4%–6%, coking coal 2 # 5%–10%, coking coal 1 # 5%–20%, coking coal 2 # 0%–2%, coking coal 3 #The blend consists of 15%–25% Canadian coking coal, 5%–15% lean coal, and 10%–13% lean coal. Studies of the flowability of individual coals revealed that Canadian coking coal has poor flowability, with a maximum flowability (MF) of only 11–37 ddpm and a narrow plastic range of 50–55°C. This narrow plastic range prevents sufficient bonding of inert components, affecting the coke's crush strength (M40). In the coal blending scheme, Canadian coking coal is used to replace a portion of the high-priced coking coal. # And reduce the price of high-priced coking coal by 1 # 2 coking coal # Dosage; and adjust coking coal 1 according to the blending ratio of Canadian coking coal. # Coking coal 3 # The proportions ensure that the final blended coal has a plasticity range of 75–85℃, a caking index (G) of 82–86, a maximum plastic layer thickness (Y) of 16–18 mm, a mineral catalytic index (MCI) of 2.5–3.0%, and an ash content (Ad) of 9.00%–10.00%. These coal blending quality requirements are based on research into the quality characteristics of Canadian coking coal.

[0016] The coal quality indicators for each type of coal are as follows:

[0017] Coal Fertilizer 1 # Sulfur content (St,d): 1.20%–1.60%, adhesion index (G) ≥ 90, plasticity range: 100–110℃.

[0018] Coal 2 # Sulfur content (St,d): 0.30%–0.70%, adhesion index (G) ≥ 90, plasticity range: 90–100℃.

[0019] 1 / 3 coking coal: sulfur content (St,d): 0.20%–0.40%, caking index (G) ≥ 90, plasticity range: 80–95℃.

[0020] Coking coal 1 # Sulfur content (St,d): 0.55%–0.75%, caking index (G): 85–90, plasticity range: 100–110℃, CSR of coke produced in a 40kg small coke oven: 55%–59%.

[0021] Coking coal 2 # Sulfur content (St,d): 1.20%–1.50%, caking index (G): 80–85, plasticity range: 70–80℃, CSR of coke produced in a 40kg small coke oven: 80%–84%.

[0022] Coking coal 3 # Sulfur content (St,d): 1.40%–1.80%, caking index (G): 85–90, plasticity range: 90–100℃, CSR of coke produced in a 40kg small coke oven: 67%–71%.

[0023] Gas coal: caking index G≥75; Gas fat coal: caking index G≥5; Lean coal: caking index G≥35.

[0024] After blending, the mixed coal needs to be crushed, with particles smaller than 3mm accounting for 68%–72% of its total mass. The plastic range of the blended coal after blending is 75–85℃, the caking index G is 82–86, the maximum thickness of the plastic layer Y is 16–18mm, the mineral catalytic index MCI is 2.5%–3.0%, and the ash content Ad is 9.00%–10.00%. This effectively expands the plastic range of the blended coal and enhances its fluidity.

[0025] The crushed mixed coal is fed into a 7m top-loading coke oven for coking. The standard temperatures on the machine side and coke side are 1250±10℃ and 1300±10℃, respectively, and the coking time is 26±2 hours.

[0026] Dry quenching is used, followed by cooling and coke removal. Coke quality is then tested, and indicators such as coke crush resistance (M40), abrasion resistance (M10), coke reactivity (CRI), and post-reaction strength (CSR) are measured.

[0027] This invention employs a method for blending Canadian coking coal with a plasticity range of <60℃ in coking, breaking away from traditional methods of replacing the same type of coal. It eliminates the boundary between coking coal and bituminous coal, further subdivides coking coal and bituminous coal from different mining sites, and optimizes blending by combining the plasticity range of the blended coal, the mineral catalytic index (MCI), the caking index (G), the maximum thickness of the plastic layer (Y), as well as ash, sulfur, and volatile matter content. This method utilizes more low-priced Canadian coking coal and less high-priced coking coal and bituminous coal. With a higher proportion of Canadian coking coal, the shatter resistance of the coke is effectively improved, thus reducing blending costs.

[0028] This invention develops a method for blending Canadian coking coal with a plasticity range of <60℃ into coking coal, achieving a blending ratio of up to 15% without altering the type of coal used. In a 7m top-charged coke oven, the resulting coke exhibits M40 ≥ 88%, M10 ≤ 6.0%, CSR ≥ 8%, and a coke quality meeting the requirements of 3000m³. 3 The above are the requirements for stable production of blast furnaces.

[0029] 3. Beneficial effects

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] This invention replaces a portion of coking coal and fat coal in coking blending with Canadian coking coal, increasing its blending ratio. Through research on the compatibility of different coking coals, an optimized coking coal blending ratio is proposed. By controlling the plasticity range, caking index G, and maximum plastic layer thickness Y of the blended coal, as well as optimizing ash, sulfur, and volatile matter content, the resulting coke meets the quality requirements of high-quality metallurgical coke and satisfies the 3000m³ requirement. 3The above blast furnaces meet stable production needs. Attached Figure Description

[0032] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that these drawings are designed for illustrative purposes only and are not intended to limit the scope of the present invention.

[0033] Figure 1 This is a random reflectance distribution diagram of the vitrinite group of Canadian coking coal according to the present invention. Detailed Implementation

[0034] The following detailed description of exemplary embodiments of the invention is taken with reference to the accompanying drawings, which form part of the description and illustrate exemplary embodiments in which the invention may be practiced. While these exemplary embodiments have been described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be implemented and various changes may be made to the invention without departing from the spirit and scope thereof. The more detailed description of embodiments of the invention below is not intended to limit the scope of the claimed invention, but is merely illustrative and not restrictive of the description of the features and characteristics of the invention, to suggest the best mode for carrying out the invention, and is sufficient to enable those skilled in the art to practice the invention. Therefore, the scope of the invention is defined only by the appended claims.

[0035] A method for blending Canadian coking coal with a plasticity range of <60℃ into coking coal includes the following steps:

[0036] Based on the current national standard testing methods, the mean random reflectance and distribution histogram of vitrinite, the plastic range of Gibbs flowability, the bonding index G, the maximum thickness of the plastic layer Y, and the mineral catalytic index MCI of Canadian coking coal were determined.

[0037] The specific coal quality indicators of the Canadian coking coal with a plasticity range <60℃ are as follows: average maximum reflectance Rran of vitrinite group is 1.20% to 1.34%, Gibbs freeness plasticity range is 50 to 55℃, freeness MF is 11 to 37 ddpm, caking index G is 76 to 80, maximum thickness of plastic layer Y is 14 to 18 mm, mineral catalytic index MCI is 1.5% to 2.0%, dry ash-free volatile matter Vdaf is 22% to 25%, sulfur content St,d is 0.30% to 0.40%, dry ash content Ad is 9.50% to 10.50%, and coke CSR of 40kg small coke oven is 73% to 77%.

[0038] Classify and select coal types for production:

[0039] Coal Fertilizer 1 #Sulfur content (St,d): 1.20%–1.60%, adhesion index (G) ≥ 90, plasticity range: 100–110℃.

[0040] Coal 2 # Sulfur content (St,d): 0.30%–0.70%, adhesion index (G) ≥ 90, plasticity range: 90–100℃.

[0041] 1 / 3 coking coal: sulfur content (St,d): 0.20%–0.40%, caking index (G) ≥ 90, plasticity range: 80–95℃.

[0042] Coking coal 1 # Sulfur content (St,d): 0.55%–0.75%, caking index (G): 85–90, plasticity range: 100–110℃, CSR of coke produced in a 40kg small coke oven: 55%–59%.

[0043] Coking coal 2 # Sulfur content (St,d): 1.20%–1.50%, caking index (G): 80–85, plasticity range: 70–80℃, CSR of coke produced in a 40kg small coke oven: 80%–84%.

[0044] Coking coal 3 # Sulfur content (St,d): 1.40%–1.80%, caking index (G): 85–90, plasticity range: 90–100℃, CSR of coke produced in a 40kg small coke oven: 67%–71%.

[0045] Gas coal: caking index G≥75; Gas-rich coal: caking index G≥85; Lean coal: caking index G≥35.

[0046] The coal blend should be made according to the following mass percentages: gas coal 20%–24%, gas-rich coal 4%–8%, 1 / 3 coking coal 3%–7%, and fat coal 1%–24%. # 4%–6%, coking coal 2 # 5%–10%, coking coal 1 # 5%–20%, coking coal 2 # 0%–2%, coking coal 3 # 15%–25%, Canadian coking coal 5%–15%, lean coal 10%–13%.

[0047] In the coal blending scheme, Canadian coking coal will be used to replace part of the high-priced coking coal. # And reduce the price of high-priced coking coal by 2 # Dosage; and adjust coking coal 1 according to the blending ratio of Canadian coking coal. # Coking coal 3 #The proportions ensure that the final blended coal has a plasticity range of 75–85℃, a bonding index G of 82–86, a maximum plastic layer thickness Y of 16–18 mm, a mineral catalytic index MCI of 2.5%–3.0%, and an ash content Ad of 9.00%–10.00%.

[0048] The specific coal blending ratios are shown in Table 1. Scheme 1 does not use Canadian coking coal. Scheme 2 directly replaces 5% of domestic coking coal with Canadian coking coal. Scheme 3 uses 5% Canadian coking coal according to the technology. Scheme 4 uses 10% Canadian coking coal according to the technology. Scheme 5 uses 15% Canadian coking coal according to the technology. The coke obtained by coking in a 7m top-charged coke oven has a crush resistance M40 of 88% to 89%, an abrasion resistance M10 of 5% to 6%, and a post-reaction strength (CSR) of 68% to 70%.

[0049] After blending, the mixed coal needs to be crushed. The mixed coal is fed into a crusher by conveyor belt and crushed. The mixed coal with a particle size of less than 3mm accounts for 68% to 72% of its total mass.

[0050] Coking is carried out by feeding crushed mixed coal into a 7m top-loading coke oven. The standard temperatures on the machine side and coke side are 1250℃ and 1300℃, respectively, and the coking time is 26 hours.

[0051] Dry quenching was used, followed by cooling and coking. Coke quality was tested, and indicators such as coke crush resistance (M40), abrasion resistance (M10), coke reactivity (CRI), and post-reaction strength (CSR) were measured. The measurement results are shown in Table 1.

[0052] Table 1. Data on coking coal blending (mass percentage) and coke quality in embodiments of the present invention.

[0053]

[0054]

[0055] As can be seen from the five schemes in Table 1, in Comparative Example 2, simply replacing domestic coking coal with Canadian coking coal in the same proportion resulted in a decrease in the coke's crush resistance strength M40 to below 88%. This was mainly because the caking index G and the maximum thickness Y of the plastic layer in the blended coal both decreased, especially the plasticity range narrowed by 12°C. This indicates that Canadian coking coal cannot fully play its role in the coking process and cannot be simply replaced by traditional coal blending methods. Therefore, Examples 1-3 adopted the Canadian coking coal replacement scheme of this invention, optimizing the coal blending based on the plasticity range, mineral catalytic index MCI, caking index G, maximum thickness Y of the plastic layer, as well as ash, sulfur, and volatile matter content, thereby replacing the corresponding high-priced coking coal and fat coal, achieving the goal of reducing coal blending costs and stabilizing coke quality.

[0056] The above description is only a specific example of the present invention. It should be noted that the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the technical concept and technical solution of the present invention, or the direct application of the technical concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A blended coal containing Canadian coking coal with a plasticity range <60℃, characterized in that, It includes 20%–24% gas coal, 4%–8% gas-rich coal, 3%–7% 1 / 3 coking coal, 9%–16% fat coal, and 25%–62% coking coal. Among them, the coking coal includes 5%–15% Canadian coking coal. The Canadian coking coal has the following characteristics: its plastic range of Kiel's fluidity is 50℃–55℃, its fluidity MF is 11–37 PPM, its caking index G is 76–80, and its maximum plastic layer thickness Y is 14–18 mm. The Canadian coking coal described has the following characteristics: average maximum reflectance (Rran) of vitrinite group 1.20%~1.34%, mineral catalytic index (MCI) 1.5%~2.0%, dry ash-free volatile matter (Vdaf) 22%~25%, sulfur content (St,d) 0.30%~0.40%, dry ash content (Ad) 9.50%~10.50%, and coke CSR (coke smelting rate) of 40kg small coke oven 73%~77%. The blended coal has the following characteristics: a plasticity range of 75-85℃, a caking index (G) of 82-86, a maximum plastic layer thickness (Y) of 16-18 mm, a mineral catalytic index (MCI) of 2.5%-3.0%, and an ash content (Ad) of 9.00%-10.00%. The fat coal includes fat coal 1 # 4%–6%, coking coal 2 # 5% to 10%, wherein the coking coal includes coking coal 1 # 5%–20%, coking coal 2 # 0%~2%, coking coal 3 # 15%–25%, Canadian coking coal 5%–15%; Wherein, MCI satisfies: 。 2. The blended coal containing Canadian coking coal with a plasticity range <60℃ as described in claim 1, characterized in that, Coal Fertilizer 1 # Sulfur content (St,d): 1.20%~1.60%, adhesion index (G) ≥ 90, plasticity range: 100~110℃; Coal 2 # Sulfur content (St,d): 0.30%~0.70%, adhesion index (G) ≥ 90, plasticity range: 90~100℃; 1 / 3 coking coal: sulfur content (St,d): 0.20~0.40%, caking index (G) ≥ 90, plasticity range: 80~95℃; Coking coal 1 # Sulfur content (St,d): 0.55~0.75%, caking index (G): 85~90, plasticity range: 100~110℃, CSR of coke produced in a 40kg small coke oven: 55%~59%; Coking coal 2 # Sulfur content (St,d): 1.20%~1.50%, caking index (G): 80~85, plasticity range: 70~80℃, CSR of coke produced in a 40kg small coke oven: 80%~84%; Coking coal 3 # Sulfur content (St,d): 1.40%~1.80%, caking index (G): 85~90, plasticity range: 90~100℃, CSR of coke produced in a 40kg small coke oven: 67%~71%; Gas coal: Caking index G≥75; Gas-rich coal: Caking index G≥85; Lean coal: Caking index G≥35.

3. The coke obtained from the blended coal according to any one of claims 1-2, characterized in that, The coke's crush resistance strength M40 ≥ 88%.

4. The coke according to claim 3, characterized in that, The coke has M10 ≤ 6.0% and CSR ≥ 68%.

5. A method for preparing the coke according to any one of claims 3-4, characterized in that, The coal is crushed and fed into a 7m top-loading coke oven for coking. The standard temperatures on the machine side and coke side are 1250±10℃ and 1300±10℃, respectively, and the coking time is 26±2 hours.

6. The method according to claim 5, characterized in that, After crushing, the blended coal with a particle size of less than 3mm accounts for 68% to 72% of its total mass.

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