Method for preparing high-quality metallurgical coke from weak caking coal

Abstract

The invention discloses a method for preparing high-quality metallurgical coke from weakly caking coal, which comprises the following steps: classifying the weakly caking coal, blending the weakly caking coal, crushing, blending the coal, charging the coal in a coke oven, leveling the coal, coking in the coke oven and quenching by a dry method, classifying the weakly caking coal according to coal types, caking indexes, vitrinite reflectance and ash alkalinity, and blending various types of weakly caking coal; the mixed weak caking coal and prime coking coal are smashed respectively, the mass ratio of the smashed prime coking coal with the granularity not exceeding 3 mm is 70%-80%, then the smashed prime coking coal is mixed with the prime coking coal in a multi-batch coal blending mode, and the proportion of the prime coking coal is controlled to be 35%-80%. According to the method, different property indexes of the weakly caking coal are subdivided, and differential blending is performed according to different properties, so that property segregation of blended coal caused by factors such as the granularity of coking coal is reduced, the accuracy and uniformity of coking coal blending are improved, large-proportion application of the weakly caking coal is realized, and high-quality metallurgical coke meeting the requirements of a blast furnace is produced.

Description

Technical Field

[0001] The invention belongs to the technical field of coking coal blending, and in particular relates to a method for preparing high-quality metallurgical coke from weakly caking coal. Background Art

[0002] Blast furnace ironmaking is the production process with the largest resource and energy consumption in the iron and steel metallurgical process, and it is also the production link with the largest carbon emissions in the iron and steel metallurgical process. Its coal-based energy consumption accounts for 70% of the energy consumption of the entire process. Coke, as the main raw material for blast furnace ironmaking, plays the role of reducing agent, material column skeleton, carburizing agent and heat supply. The stability of coke quality is crucial to the efficient operation of the blast furnace. my country is a country with large coal resource reserves, but coking coal resources are insufficient, accounting for only 9.45% of my country's coal resource reserves. High-quality coking coal represented by coking coal and fat coal only accounts for 37% of coking coal resources. The raw materials used to produce metallurgical coke are coking coal and fat coal, which have relatively small coal resource reserves. According to the current reserves and annual consumption of coking coal resources that have been explored in my country, it is estimated that domestic coking coal resources can be used for another 40-60 years. To this end, whether from the perspective of resource strategy or the urgent need to implement pollution reduction and carbon reduction in the steel industry, it is urgent to master the efficient utilization of non-high-quality coking coal and weakly adhesive coal, optimize the coking coal blending structure, save high-quality coking coal resources, and achieve sustainable development and utilization of coal resources.

[0003] Patents CN201210161209.7 and CN201410067852.2 disclose methods for blending gas coal for coking, which mainly achieve the application of gas coal blending with higher volatile matter by controlling the bonding index and the thickness of the colloid layer; Patents CN201710918977.5, CN201711041930.1 and CN201711041930.1 disclose methods for blending high-grade or highly metamorphic weakly caking coal for coking, among which CN2017109 18977.5 is controlled by the colloidal layer index, the particle size of the blended coal, the coking process index and the coke microstructure index. CN201711041930.1 discloses that high-order weakly coking coal, i.e. lean coal, is blended by adjusting the particle size to change the interface bonding force. CN201711041930.1 discloses a method for coking with the participation of high-metamorphic coking coal distinguished by the reflectivity of the vitrinite group, classifies and evaluates the high-metamorphic coking coal, and then adjusts the proportion according to the different properties of different types of coal. Patent CN202210350145.9 introduces a method for coking coal blending to improve the quality of coke, which is mainly aimed at multi-range classification of the particle size of coking coal. The purpose is to improve the coking and coking properties of coking coal caused by the change of the particle size of coking coal, make full use of high-quality coking coal, and use sticky waste such as waste plastics as a binder to mix with small-particle inert components, and finally achieve the purpose of refined coal blending and high-quality coke production. Patent CN202210350148.2 is about screening coking coal of different particle sizes, and then testing the bonding and coking properties of coking coal in different particle size ranges. According to the properties of coking coal of different particle sizes, targeted multiple screening and blending are carried out to improve the accuracy and homogeneity of coking coal blending. Neither of the above two patents involves the difference in property indicators caused by different particle sizes. By subdividing weakly coking coal by multiple factors and then blending multiple batches to complement the advantages and disadvantages of coking coal of different particle sizes.

[0004] The above method mainly mixes weakly caking coal with different property indicators with main coking coal. The ash composition and alkalinity limits are not considered in the coal blending process, especially the sub-classification of different weakly caking coals, differential blending of weakly caking coals and mixing operations are not involved. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing high-quality metallurgical coke from weakly caking coal. By subdividing the weakly caking coal into different property indicators and performing differential blending according to different properties, the segregation of the properties of the blended coal caused by factors such as the particle size of coking coal can be reduced, the accuracy and uniformity of the coking coal blending can be improved, and a large proportion of weakly caking coal can be used to produce high-quality metallurgical coke that meets the requirements of blast furnaces. Furthermore, the weakly caking coking coal can be used to optimize cost control, thereby providing new methods and ideas for the production of coking coal blending.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing high-quality metallurgical coke from weakly caking coal comprises the following steps: classifying the weakly caking coal, mixing the weakly caking coal, crushing, mixing and blending the coal, charging the coke oven with coal and leveling the coal, coking the coke oven, and dry quenching the coke, specifically:

[0008] Weakly caking coal is classified according to coal type, caking index, vitrinite reflectance, and ash alkalinity, and multiple types of weakly caking coal are mixed; the mixed weakly caking coal and main coking coal are crushed separately, and the main coking coal with a particle size of no more than 3 mm accounts for 70% to 80% by weight after crushing, and then mixed with the main coking coal in multiple batches, and the main coking coal ratio is controlled at 35% to 80%; if the volatile matter V daf ≥27%, the mass proportion of the weakly caking coal after crushing with a particle size of 1 to 3 mm is greater than 50%, and the coal blending ratio is controlled at 5% to 25%; if the volatile matter V daf <27%, the mass proportion of the mixed weakly caking coal with a particle size of 1-3mm after crushing does not exceed 50%, and the coal blending ratio is controlled at 15% to 35%. Differential crushing is carried out for weakly caking coal with different property indicators, that is, low-metamorphic coal with higher volatile matter is appropriately crushed to achieve full separation of low-metamorphic coal colloids; and high-metamorphic coal with lower volatile matter is finely crushed to achieve effective bonding and coking of high-metamorphic coal by main coking coal. The mixed coal includes mixed weakly caking coal, coking coal, fat coal, and 1 / 3 coking coal. The mass proportion of the mixed coal is 5% to 35% of weakly caking coal, 15% to 50% of coking coal, 20% to 30% of fat coal, and 5% to 30% of 1 / 3 coking coal.

[0009] Furthermore, weakly caking coal is classified into three types: lean coal, lean coal and lean coal as C1, gas coal, 1 / 2 medium caking coal and weakly caking coal as C2, non-caking coal and long flame coal as C3; weakly caking coal is classified into three types according to the caking index: 65≥G>50, 50≥G≥25, G<25 as S1, S2 and S3 respectively; weakly caking coal is classified into three types according to the vitrinite reflectance: Rmax≤0.8 and Rmax≥1.7 as P1 and P2 respectively; weakly caking coal is classified into two types according to the ash alkalinity: 0.1≥B>0.086 and 0.13≥B>0.1 as L1 and L2 respectively. Differential utilization of weakly caking coal with different properties can maximize the advantages of weakly caking coal.

[0010] Furthermore, the loading order of multiple types of weakly caking coal mixtures is batch A → batch B → batch C → batch D. The four batches of weakly caking coal, batch A, batch B, batch C, and batch D, are mixed with the main coking coal through the coal blending plate through the main feeding belt in sequence, and finally the coking blending coal is transported to the coke oven coal tower through the belt.

[0011] Furthermore, batch A is composed of a mixture of weakly caking coal of type C1 and weakly caking coal of type S3; batch B is composed of a mixture of weakly caking coal of type C3, weakly caking coal of type S2 and weakly caking coal of type P2; batch C is composed of a mixture of weakly caking coal of type C2 and weakly caking coal of type L1; batch D is composed of a mixture of weakly caking coal of type C2, weakly caking coal of type S1, weakly caking coal of type P1 and weakly caking coal of type L2, and each batch has no less than 2 types of coal. By crushing weakly caking coal and mixing and blending coal in multiple batches, the properties and particle size distribution of weakly caking coal can be uniformed, and the segregation of the properties of the blended coal caused by simple blending can be reduced.

[0012] Furthermore, the weakly caking coal refers to any one of lean coal, lean and lean coal, lean coal, gas coal, 1 / 2 medium-caking coal, weakly caking coal, non-caking coal, and long flame coal, and the weakly caking coal has a G value ≤65.

[0013] Furthermore, the weakly caking coal ash has FeO≤4.95%, K2O≤0.94%, Na2O≤0.43%, and basicity Controlled within the range of 0.086 to 0.13. Weakly caking coal is a single type of coal, that is, a single source, a single coal seam or a single origin of coal, the distribution diagram of the vitrinite reflectance of the coal rock has only one convex peak, and the vitrinite reflectance Rmax ≤ 0.8 or Rmax ≥ 1.7.

[0014] Furthermore, the coke oven coal loading and coal leveling refers to loading the coke oven coal tower and coal into the coke oven through the coal loading car. During the coal loading, multiple coal loading ports of the coke oven are loaded with coal at the same time. When the coal loading height reaches different positions, the coal is repeatedly leveled through the coal leveling rod until the coal loading operation is completed and the coal leveling rod is withdrawn from the carbonization chamber. The coal loading height refers to the distance between the peak of the coal loading pile and the bottom of the carbonization chamber, and the different positions are 1 / 3 and 2 / 3 of the height of the carbonization chamber.

[0015] Furthermore, after the coal loading is completed, the mixed coal is carbonized in a closed carbonization chamber for 19 to 24 hours, the coke cake temperature eventually reaches 1100°C, and the standard fire channel temperature of the carbonization chamber is controlled at 1290 to 1350°C.

[0016] Furthermore, a dry quenching coke oven is used to cool the red coke after dry distillation and coking. The cooling medium is N2. The N2 is used to exchange heat with the red coke and then to exchange heat with boiler steam. Finally, steam with a temperature of 450-540°C and a pressure of 4.5-9.5MPa is produced for power generation.40 85% to 90%, CSR 65% to 70%, meeting 3200m 3 And above blast furnace production requirements.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1) By classifying different kinds of weakly caking coal, including coal type, caking index, vitrinite reflectance, ash alkalinity, etc., different utilization of weakly caking coal of different properties is achieved, and the low-cost advantage of weakly caking coal is maximized; 2) The weakly caking coal is crushed and blended in multiple batches, which can improve the properties and particle size distribution uniformity of the weakly caking coal, reduce the segregation of the property indicators of the blended coal caused by simple mixing, and achieve accurate coal blending; 3) Differential crushing is performed for weakly caking coal with different property indicators, that is, low-metamorphic coal with higher volatile matter is crushed to achieve full separation of low-metamorphic coal colloids; and high-metamorphic coal with lower volatile matter is finely crushed to achieve effective bonding and coking of main coking coal to high-metamorphic coal; 4) The present invention realizes the large-scale application of weakly caking coal in the preparation of metallurgical coke, and the maximum coal blending ratio reaches more than 35%, thereby optimizing cost control by using weakly caking coking coal, and the coke quality M 40 The highest reaches 90%, CSR reaches 70%, and there is sustainable development in the utilization of my country's coal resources. DETAILED DESCRIPTION

[0019] The present invention is described in more detail below through examples.

[0020] Embodiment 1:

[0021] A method for preparing high-quality metallurgical coke from weakly caking coal, the specific contents are as follows:

[0022] 1. Classification and blending of weakly caking coal.

[0023] 1) Weakly caking coal is classified into three types: lean coal, lean and lean coal, and lean coal as C1; gas coal, 1 / 2 medium caking coal, and weakly caking coal as C2; and non-caking coal and long flame coal as C3;

[0024] 2) The weakly caking coal is classified by caking index, 65≥G>50, 50≥G≥25, G<25 are S1, S2, S3 respectively;

[0025] 3) The weakly caking coal is classified by vitrinite reflectance, Rmax≤0.8 and Rmax≥1.7 are classified as P1 and P2 respectively;

[0026] 4) Classify weakly caking coal by ash content and alkalinity. 0.1≥B>0.086 and 0.13≥B>0.1 are classified as L1 and L2 respectively;

[0027] 5) Use multiple weakly-bonded single-type coal belts to mix and blend weakly-bonded coals with multiple properties. The loading order is batch A → batch B → batch C → batch D. The four batches of weakly-bonded coal, batch A, batch B, batch C, and batch D, are mixed with the main coking coal through the coal blending plate through the main loading belt in turn, and finally the coking blending coal is transported to the coke oven coal tower through the belt.

[0028] Batch A is composed of a mixture of C1 weakly caking coal and S3 weakly caking coal;

[0029] Batch B is composed of a mixture of C3 weakly caking coal, S2 weakly caking coal, and P2 weakly caking coal;

[0030] Batch C is composed of a mixture of C2 weakly caking coal and L1 weakly caking coal;

[0031] Batch D is composed of a mixture of C2 weakly caking coal, S1 weakly caking coal, P1 weakly caking coal and L2 weakly caking coal.

[0032] 2. Crushing. The mixed weakly caking coal and main coking coal are crushed separately, and the main coking coal with a particle size of no more than 3mm accounts for 75% of the total mass. Then, the main coking coal is mixed with the main coking coal in 4 batches, and the main coking coal ratio is controlled at 60%. The volatile matter V of the mixed weakly caking coal is daf The weight ratio of the mixed weakly caking coal with a particle size of 1 to 3 mm after crushing is 60%, and the coal blending ratio is controlled at 15%.

[0033] 3. Mixed coal blending. The mixed weakly caking coal is mixed with coking coal, fat coal, and 1 / 3 coking coal through a coal blending plate and the main coking coal, and finally the coking blended coal is transported to the coke oven coal tower through a belt. The blending ratio of the mixed weakly caking coal, coking coal, fat coal, and 1 / 3 coking coal is 15%:40%:20%:25%. The method of multi-batch batching is adopted, the main coking coal is mixed through a coal blending plate, and finally the coking blended coal is transported to the coke oven coal tower through a belt. The above process improves the properties of the weakly caking coal and the uniformity of the particle size distribution, and reduces the segregation of the properties of the blended coal caused by simple blending.

[0034] 4. Coal loading and leveling in the coke oven. The mixed coal is loaded into the coke oven through the coal loading car. When loading, multiple coal loading ports of the coke oven are loaded with coal at the same time. When the coal loading height reaches 1 / 3 of the height of the carbonization chamber, the coal leveling rod is used to level the coal twice, and then the coal loading continues. When the height reaches 2 / 3 of the height of the carbonization chamber, the coal leveling rod is used to level the coal several times, and the coal loading operation is carried out at the same time. After the completion, the coal leveling rod is withdrawn from the carbonization chamber.

[0035] 5. Coking in coke ovens. After the coal is loaded, the mixed coal is dry distilled in a closed carbonization chamber for 19 hours. The coke cake temperature eventually reaches 1100°C, and the standard fire channel temperature of the carbonization chamber is controlled at 1350°C.

[0036] 6. Dry quenching. The dry quenching coke oven is used to cool the red coke after dry distillation. The cooling medium is N2. The N2 is used to exchange heat with the red coke and then the boiler steam is used to exchange heat. Finally, steam with a temperature of 450°C and a pressure of 4.5MPa is produced for power generation. 40 89% to 90%, CSR 69% to 70%, meeting 4000m 3 Blast furnace production requirements.

[0037] Embodiment 2:

[0038] A method for preparing high-quality metallurgical coke from weakly caking coal, the specific contents are as follows:

[0039] 1. Classification and blending of weakly caking coal.

[0040] 1) Weakly caking coal is classified into three types: lean coal, lean and lean coal, and lean coal as C1; gas coal, 1 / 2 medium caking coal, and weakly caking coal as C2; and non-caking coal and long flame coal as C3;

[0041] 2) The weakly caking coal is classified by caking index, 65≥G>50, 50≥G≥25, G<25 are S1, S2, S3 respectively;

[0042] 3) The weakly caking coal is classified by vitrinite reflectance, Rmax≤0.8 and Rmax≥1.7 are classified as P1 and P2 respectively;

[0043] 4) Classify weakly caking coal by ash content and alkalinity. 0.1≥B>0.086 and 0.13≥B>0.1 are classified as L1 and L2 respectively;

[0044] 5) Multiple weakly-bonded single-species coal belts are used to mix and blend weakly-bonded coals of multiple properties. The loading order is batch A → batch B → batch C → batch D. The four batches of weakly-bonded coals of batch A, batch B, batch C, and batch D are mixed with the main coking coal through the coal blending plate through the main feeding belt in turn, and finally the coking blended coal is transported to the coke oven coal tower through the belt;

[0045] Batch A is composed of a mixture of C1 weakly caking coal and S3 weakly caking coal;

[0046] Batch B is composed of a mixture of C3 weakly caking coal, S2 weakly caking coal, and P2 weakly caking coal;

[0047] Batch C is composed of a mixture of C2 weakly caking coal and L1 weakly caking coal;

[0048] Batch D is composed of a mixture of C2 weakly caking coal, S1 weakly caking coal, P1 weakly caking coal and L2 weakly caking coal.

[0049] 2. Crushing. The mixed weakly caking coal and main coking coal are crushed separately, and the main coking coal with a particle size of no more than 3mm accounts for 70% of the total mass. Then, the main coking coal is mixed with the main coking coal in 4 batches, and the main coking coal ratio is controlled at 60%. The volatile matter V of the mixed weakly caking coal is daf The weight ratio of the mixed weakly caking coal with a particle size of 1-3 mm after crushing is 50%, and the coal blending ratio is controlled at 35%.

[0050] 3. Mixed coal blending. The mixed weakly caking coal is mixed with coking coal, fat coal, and 1 / 3 coking coal through a coal blending plate and the main coking coal, and finally the coking blended coal is transported to the coke oven coal tower through a belt. The blending ratio of the mixed weakly caking coal, coking coal, fat coal, and 1 / 3 coking coal is 35%:40%:20%:5%. The batching is carried out in multiple batches, and the main coking coal is mixed through a coal blending plate, and finally the coking blended coal is transported to the coke oven coal tower through a belt. The above process improves the properties of the weakly caking coal and the uniformity of the particle size distribution, and reduces the segregation of the properties of the blended coal caused by simple blending.

[0051] 4. Coal loading and leveling in the coke oven. The mixed coal is loaded into the coke oven through the coal loading car. During the loading, multiple coal loading ports of the coke oven are loaded with coal at the same time. When the coal loading height reaches 2 / 3 of the height of the carbonization chamber, the coal leveling rod repeatedly levels the coal and performs the coal loading operation at the same time. After the completion, the coal leveling rod is withdrawn from the carbonization chamber.

[0052] 5. Coking in coke ovens. After the coal is loaded, the mixed coal is dry distilled in a closed carbonization chamber for 19 hours. The coke cake temperature eventually reaches 1100°C, and the standard fire channel temperature of the carbonization chamber is controlled at 1290°C.

[0053] 6. Dry quenching. The dry quenching coke oven is used to cool the red coke after dry distillation. The cooling medium is N2. The N2 is used to exchange heat with the red coke and then the boiler steam is used to exchange heat. Finally, steam with a temperature of 540°C and a pressure of 9.5MPa is produced for power generation. 40 85%~88%, CSR 65%~68%, meeting 2850m 3 Blast furnace production requirements.

[0054] Embodiment 3:

[0055] A method for preparing high-quality metallurgical coke from weakly caking coal, the specific contents are as follows:

[0056] 1. Classification and blending of weakly caking coal.

[0057] 1) Weakly caking coal is classified into three types: lean coal, lean and lean coal, and lean coal as C1; gas coal, 1 / 2 medium caking coal, and weakly caking coal as C2; and non-caking coal and long flame coal as C3;

[0058] 2) The weakly caking coal is classified by caking index, 65≥G>50, 50≥G≥25, G<25 are S1, S2, S3 respectively;

[0059] 3) The weakly caking coal is classified by vitrinite reflectance, Rmax≤0.8 and Rmax≥1.7 are classified as P1 and P2 respectively;

[0060] 4) Classify weakly caking coal by ash content and alkalinity. 0.1≥B>0.086 and 0.13≥B>0.1 are classified as L1 and L2 respectively;

[0061] 5) Multiple weakly-bonded single-species coal belts are used to mix and blend weakly-bonded coals of multiple properties. The loading order is batch A → batch B → batch C → batch D. The four batches of weakly-bonded coals of batch A, batch B, batch C, and batch D are mixed with the main coking coal through the coal blending plate through the main feeding belt in turn, and finally the coking blended coal is transported to the coke oven coal tower through the belt;

[0062] Batch A is composed of a mixture of C1 weakly caking coal and S3 weakly caking coal;

[0063] Batch B is composed of a mixture of C3 weakly caking coal, S2 weakly caking coal, and P2 weakly caking coal;

[0064] Batch C is composed of a mixture of C2 weakly caking coal and L1 weakly caking coal;

[0065] Batch D is composed of a mixture of C2 weakly caking coal, S1 weakly caking coal, P1 weakly caking coal and L2 weakly caking coal.

[0066] 2. Crushing. The weakly caking coal and the main coking coal are crushed separately, and the main coking coal with a particle size of no more than 3 mm accounts for 80% of the total mass. Then, the main coking coal is mixed with the main coking coal in 4 batches, and the main coking coal ratio is controlled at 65%. The volatile matter V of the weakly caking coal after mixing is da The weight ratio of the mixed weakly caking coal with a particle size of 1 to 3 mm after crushing is 65%, and the coal blending ratio is controlled at 25%.

[0067] 3. Mixed coal blending. The mixed weakly caking coal is mixed with coking coal, fat coal, and 1 / 3 coking coal through a coal blending plate and the main coking coal, and finally the coking blended coal is transported to the coke oven coal tower through a belt. The blending ratio of the mixed weakly caking coal, coking coal, fat coal, and 1 / 3 coking coal is 25%: 45%: 20%: 10%. The batching is carried out in multiple batches, and the main coking coal is mixed through a coal blending plate, and finally the coking blended coal is transported to the coke oven coal tower through a belt. The above process improves the properties of the weakly caking coal and the uniformity of the particle size distribution, and reduces the segregation of the properties of the blended coal caused by simple blending.

[0068] 4. Coal loading and leveling in the coke oven. The mixed coal is loaded into the coke oven through the coal loading car. When loading, multiple coal loading ports of the coke oven are loaded with coal at the same time. When the coal loading height reaches 1 / 3 of the height of the carbonization chamber, the coal leveling rod is used to level the coal twice, and the coal loading operation is carried out at the same time. After the completion, the coal leveling rod is withdrawn from the carbonization chamber.

[0069] 5. Coking in coke ovens. After the coal is loaded, the mixed coal is dry distilled in a closed carbonization chamber for 22 hours. The coke cake temperature eventually reaches 1100°C, and the standard fire channel temperature of the carbonization chamber is controlled at 1290°C.

[0070] 6. Dry quenching. The dry quenching coke oven is used to cool the red coke after dry distillation. The cooling medium is N2. The N2 is used to exchange heat with the red coke and then to exchange heat with boiler steam. Finally, steam with a temperature of 500°C and a pressure of 6MPa is produced for power generation. 40 87% to 88%, CSR 68% to 70%, meeting 3200m 3 Blast furnace production requirements.

[0071] It is to be noted that the above embodiments are only for illustrating the technical concept and features of the present invention, and are not intended to limit the present invention. Any equivalent replacement or modification that does not deviate from the essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for preparing high-quality metallurgical coke from weakly caking coal, characterized in that: The invention comprises the classification of weakly caking coal, blending of weakly caking coal, crushing, blending of coal, coke oven charging, flat coal, coke oven coking, and dry quenching. The weakly caking coal is classified according to the type of coal, the caking index, the reflectance of the vitrinite group, and the ash alkalinity, and multiple types of weakly caking coal are blended; the blended weakly caking coal and the main coking coal are crushed respectively, and the main coking coal with a particle size of no more than 3 mm accounts for 70% to 80% by weight after the crushing, and then the main coking coal is mixed in a multi-batch blending method, and the proportion of the main coking coal is controlled at 35% to 80%; if the volatile matter V of the weakly caking coal after blending is less than 3 mm, the main coking coal is blended in a multi-batch blending method, and the proportion of the main coking coal is controlled at 35% to 80%; if the volatile matter V daf ≥27%, the mass proportion of the weakly caking coal after crushing with a particle size of 1 to 3 mm is greater than 50%, and the coal blending ratio is controlled at 5% to 25%; if the volatile matter V daf <27%, the mass proportion of the mixed weakly caking coal with a particle size of 1 to 3 mm after crushing does not exceed 50%, and the coal blending ratio is controlled at 15% to 35%; the mass proportion of the mixed blended coal is 5% to 35% of weakly caking coal, 15% to 50% of coking coal, 20% to 30% of fat coal, and 5% to 30% of 1 / 3 of coking coal.

2. The method for preparing high-quality metallurgical coke from weakly caking coal according to claim 1, characterized in that: The weakly coking coal is classified into three categories: lean coal, lean coal and lean coal as C1, gas coal, 1 / 2 medium coking coal and weakly coking coal as C2, and non-coking coal and long flame coal as C3. The weakly coking coal is classified by coking index as 65≥G>50, 50≥G≥25, and G<25 as S1, S2, and S3 respectively. The weakly coking coal is classified by vitrinite reflectance as Rmax≤0.8 and Rmax≥1.7 as P1 and P2 respectively. The weakly coking coal is classified by ash alkalinity as 0.1≥B>0.086 and 0.13≥B>0.1 as L1 and L2 respectively.

3. The method for preparing high-quality metallurgical coke from weakly caking coal according to claim 1, characterized in that: The loading order of multiple types of weakly caking coal mixtures is batch A → batch B → batch C → batch D. The four batches of weakly caking coal, batch A, batch B, batch C, and batch D, are mixed with the main coking coal through the coal blending plate through the main feeding belt in sequence, and finally the coking blending coal is transported to the coke oven coal tower through the belt.

4. The method for preparing high-quality metallurgical coke from weakly caking coal according to claim 3, characterized in that: Batch A is composed of a mixture of Class C1 weakly caking coal and Class S3 weakly caking coal; Batch B is composed of a mixture of Class C3 weakly caking coal, Class S2 weakly caking coal and Class P2 weakly caking coal; Batch C is composed of a mixture of Class C2 weakly caking coal and Class L1 weakly caking coal; Batch D is composed of a mixture of Class C2 weakly caking coal, Class S1 weakly caking coal, Class P1 weakly caking coal and Class L2 weakly caking coal, and each batch contains no less than two types of coal.

5. The method for preparing high-quality metallurgical coke from weakly caking coal according to claim 1, characterized in that: The weakly caking coal is any one of lean coal, lean and lean coal, lean coal, gas coal, 1 / 2 medium-caking coal, weakly caking coal, non-caking coal, and long flame coal, and the G value of the weakly caking coal is ≤65.

6. The method for preparing high-quality metallurgical coke from weakly caking coal according to claim 1 or 2, characterized in that: The weakly caking coal ash contains FeO≤4.95%, K2O≤0.94%, Na2O≤0.43%, and basicity Controlled within the range of 0.086 to 0.13; weakly coking coals are all single coal species, that is, single mineral source, single coal seam coal or single origin coal species, the vitrinite reflectance distribution diagram of the coal rock has only one convex peak, and the vitrinite reflectance Rmax≤0.8 or Rmax≥1.

7.

7. The method for preparing high-quality metallurgical coke from weakly caking coal according to claim 1, characterized in that: The coke oven coal loading and coal leveling is to load the mixed mixed coal into the coke oven through a coal loading car. During coal loading, multiple coal loading ports of the coke oven are loaded with coal at the same time. When the coal loading height reaches different positions, the coal is repeatedly leveled through the coal leveling rod until the coal loading operation is completed and the coal leveling rod is withdrawn from the carbonization chamber.

8. The method for preparing high-quality metallurgical coke from weakly caking coal according to claim 7, characterized in that: The coal loading height refers to the distance between the peak of the coal pile and the bottom of the carbonization chamber, and the different positions are 1 / 3 and 2 / 3 of the height of the carbonization chamber.

9. The method for preparing high-quality metallurgical coke from weakly caking coal according to claim 1, characterized in that: After the coal is loaded, the mixed coal is distilled in a closed carbonization chamber for 19 to 24 hours. The coke temperature eventually reaches 1100°C, and the standard fire channel temperature of the carbonization chamber is controlled at 1290 to 1350°C.

10. The method for preparing high-quality metallurgical coke from weakly caking coal according to claim 1, characterized in that: The dry quenching coke oven is used to cool the red coke after dry distillation and the waste heat is utilized after the cooling medium exchanges heat with the red coke.

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