A method for blending coal under low load production conditions

Abstract

The application discloses a coal blending method under low load production conditions, which is prepared from the following raw materials in percentage by mass: 25-30% of coking coal, 25-27% of fat coal, 13-18% of 1 / 3 coking coal, 13-15% of lean coal and 10-12% of poor lean coal. The optimization steps are as follows: blending: the coal in the coal blending tank is mixed according to the set proportion; crushing: the blended coal is crushed into blended coal by a crusher; coking: the crushed blended coal is loaded into a coke oven through a charging hole of the coke oven for coking; and coke quenching: the mature coke is discharged after being cooled by a dry coke quenching device to form finished coke. The performance indexes of the obtained coke meet the following requirements: ash content ≤13, sulfur content ≤0.60, drum strength ≥88%, wear resistance ≤6.2%, thermal strength ≥69% and reactivity ≤21%. The application prolongs the turnover time, adjusts the thermal system of the coke oven, optimizes the coal blending structure, reduces the sulfur content of the coke and the cost, reduces the volatile matter of the blended coal, realizes the balance of the coal gas pipe network, and ensures the relative stability of the coke quality and yield.

Description

Technical Field

[0001] This invention relates to the field of coal, and in particular to a coal blending method under low-load production conditions. Background Technology

[0002] Under normal production conditions, the coke oven turnaround time (the time interval between two coke pushes in the same carbonization chamber during coke oven operation) is relatively fixed, and the coal blending structure is also relatively stable. The turnaround time of Angang's 7-meter coke oven is 20 hours, the standard temperature is controlled at 1220℃ on the machine side and 1270℃ on the coke side. In the coal blending structure, the proportion of coking coal and fat coal is basically controlled at 65%-67% (5%-8% of high-sulfur coking coal), the proportion of lean coal is 15%-17%, the volatile matter of blended coal is controlled at 25%-27%, and the sulfur content of coke is between 0.7%-0.8%. Due to environmental protection control, some production lines have stopped production, and the coke oven turnaround time has been extended from 20 hours to 38 hours. In order to balance the gas, reduce the sulfur content of coke, and stabilize the quality of coke, it is necessary to optimize the coal blending structure, reduce the volatile matter of blended coal, and stop using high-sulfur coal.

[0003] Coke oven production restriction refers to maintaining low-load production by extending the coking time when normal production cannot be maintained for a certain period due to natural disasters or other objective reasons. The main characteristic of this extended coking time process is that the coke remains in the carbonization chamber for a period after maturation before being discharged; the longer the coking time, the longer the oven shut-in time after maturation. Calculations show that when the production capacity of a large coke oven is reduced to 10% of its design capacity, the amount of gas produced can meet the minimum heating requirements. However, because the graphite on the carbonization chamber walls has been burned off, the leakage of raw gas increases. For safety reasons, it is advisable for large coke ovens to operate at no less than 15% of their design capacity, medium-sized coke ovens at no less than 20%, and small coke ovens at no less than 25%. Therefore, we propose a coal blending method under low-load production conditions to address these issues. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, the purpose of this invention is to provide a solution for situations where coke oven turnaround time is extended from 19 hours to 38 hours due to environmental regulations, some production lines are shut down, and gas production needs to be reduced to balance the gas supply. In order to reduce coke sulfur content and costs, the invention optimizes the coal blending structure under low load conditions to ensure stable coke quality.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0006] A coal blend for low-load production conditions comprises, by mass percentage, the following raw materials: 25-30% coking coal, 25-27% fat coal, 13-18% 1 / 3 coking coal, 13-15% lean coal, and 10-12% semi-lean coal.

[0007] A coal blending method under low-load production conditions, characterized in that the optimization steps are as follows:

[0008] (1) Batching: The coal types in the coal mixing tank are mixed in the set proportions: 30% coking coal, 27% fat coal, 18% 1 / 3 coking coal, 14% lean coal, and 11% semi-lean coal;

[0009] (2) Crushing: The blended coal is fed into a crusher and crushed to form blended coal;

[0010] (3) Coking: The crushed blended coal is loaded into the coking oven through the coking oven charging hole for coking;

[0011] (4) Quenching: Mature coke is cooled and discharged as finished coke through a dry quenching device.

[0012] Furthermore, the performance indicators of the obtained coke are as follows: ash content 12.44%, sulfur content 0.53%, drum strength 89.5%, abrasion resistance 6.0%, thermal strength 71.1%, and reactivity 19.85%.

[0013] Furthermore, in the crushing step, the fineness of the crushed coal reaches more than 78%, and the various coal types are mixed evenly during the crushing process to ensure the uniformity and stability of the coal quality.

[0014] Furthermore, in the coking step, mature coke is obtained after 38 hours of high-temperature dry distillation, with the standard temperature controlled at 1170℃ on the machine side and 1190℃ on the coke side.

[0015] Furthermore, under minimum load conditions, the turnaround time is extended, and the standard temperature of the coke oven is correspondingly reduced; the volatile matter content of the blended coal decreases from 25-26% to about 24%, reducing the amount of coal gas produced and stabilizing the coal gas balance; the coke strength index remains stable above 89%; and under environmental protection control, the coke sulfur content is controlled below 0.6%.

[0016] In summary, the present invention has the following beneficial effects:

[0017] 1. The turnaround time has been significantly extended, so the standard temperature has been appropriately reduced to ensure the stability of the coke oven thermal regime;

[0018] 2. To reduce gas production, the proportion of coking coal and fat coal in the coal blending structure will be reduced by 1 / 3, and the proportion of lean coal will be increased accordingly.

[0019] 3. To reduce costs, extending the turnover time helps increase the proportion of cheaper 1 / 3 coking coal and lean coal, thereby reducing coke costs. Attached Figure Description

[0020] Figure 1 This is an overall structural diagram of a coal blending method under low-load production conditions according to the present invention. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to the accompanying drawings.

[0022] Identical parts are indicated by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, while the terms "bottom surface," "top surface," "inner," and "outer" refer to directions toward or away from the geometric center of a specific part, respectively.

[0023] Example 1

[0024] Reference Figure 1 As shown, this is a preferred embodiment of the present invention, a coal blending method under low-load production conditions, comprising the following raw materials prepared by mass percentage: 30% coking coal, 25% fat coal, 18% 1 / 3 coking coal, 15% lean coal, and 12% semi-lean coal.

[0025] A coal blending method under low-load production conditions, characterized in that the optimization steps are as follows:

[0026] (1) Batching: The coal types in the coal mixing tank are mixed in the set proportions: 30% coking coal, 25% fat coal, 18% 1 / 3 coking coal, 15% lean coal, and 12% semi-lean coal;

[0027] (2) Crushing: The blended coal is fed into the crusher for crushing. The fineness of the crushed blended coal reaches more than 78%. During the crushing process, the various coal types are mixed evenly to ensure the uniformity and stability of the coal quality.

[0028] (3) Coking: The crushed blended coal is loaded into the coking oven through the coking oven charging hole for coking;

[0029] (4) Quenching: The mature coke is discharged as finished coke through a dry quenching device and then undergoes 38 hours of high-temperature dry distillation. The standard temperature is controlled at 1170℃ on the machine side and 1190℃ on the coke side to obtain coke.

[0030] The performance indicators of the obtained coke are as follows: ash content 12.47%, sulfur content 0.52%, drum strength 90.0%, abrasion resistance 5.5%, thermal strength 70.2%, and reactivity 20.35%.

[0031] Example 2

[0032] Reference Figure 1 As shown, this is a preferred embodiment of the present invention, a coal blending method under low-load production conditions, comprising the following raw materials prepared by mass percentage: 28% coking coal, 27% fat coal, 17% 1 / 3 coking coal, 16% lean coal, and 12% semi-lean coal.

[0033] A coal blending method under low-load production conditions, characterized in that the optimization steps are as follows:

[0034] (1) Batching: The coal types in the coal mixing tank are mixed in the set proportions: coking coal 29%, fat coal 26%, 1 / 3 coking coal 17%, lean coal 16%, and semi-lean coal 12%;

[0035] (2) Crushing: The blended coal is fed into the crusher for crushing. The fineness of the crushed blended coal reaches more than 78%. During the crushing process, the various coal types are mixed evenly to ensure the uniformity and stability of the coal quality.

[0036] (3) Coking: The crushed blended coal is loaded into the coking oven through the coking oven charging hole for coking;

[0037] (4) Quenching: The mature coke is discharged as finished coke through a dry quenching device and then undergoes 38 hours of high-temperature dry distillation. The standard temperature is controlled at 1170℃ on the machine side and 1190℃ on the coke side to obtain coke.

[0038] The performance indicators of the obtained coke are as follows: ash content 12.52%, sulfur content 0.52%, drum strength 89.7%, abrasion resistance 6.1%, thermal strength 72.7%, and reactivity 18.97%.

[0039] Example 3

[0040] Reference Figure 1 As shown, this is a preferred embodiment of the present invention, a coal blending method under low-load production conditions, comprising the following raw materials prepared by mass percentage: 30% coking coal, 27% fat coal, 18% 1 / 3 coking coal, 14% lean coal, and 11% semi-lean coal.

[0041] A coal blending method under low-load production conditions, characterized in that the optimization steps are as follows:

[0042] (1) Batching: The coal types in the coal mixing tank are mixed in the set proportions: 30% coking coal, 27% fat coal, 18% 1 / 3 coking coal, 14% lean coal, and 11% semi-lean coal;

[0043] (2) Crushing: The blended coal is fed into the crusher for crushing. The fineness of the crushed blended coal reaches more than 78%. During the crushing process, the various coal types are mixed evenly to ensure the uniformity and stability of the coal quality.

[0044] (3) Coking: The crushed mixture is loaded into the coking oven through the coking oven charging hole for coking;

[0045] (4) Quenching: The mature coke is discharged as finished coke through a dry quenching device and then undergoes 38 hours of high-temperature dry distillation. The standard temperature is controlled at 1170℃ on the machine side and 1190℃ on the coke side to obtain coke.

[0046] The performance indicators of the obtained coke are as follows: ash content 12.44%, sulfur content 0.53%, drum strength 89.5%, abrasion resistance 6.0%, thermal strength 71.1%, and reactivity 19.85%.

[0047] This embodiment sets up a control group with the following ingredients: 31% coking coal, 29% fat coal, 13% 1 / 3 coking coal, 16% lean coal, and 11% semi-lean coal; other operating parameters are the same as in this embodiment. This embodiment increases the proportion of coking coal by 1% and the proportion of fat coal by 2%.

[0048] Compared to the control group, the coke ash content in this embodiment was 12.64%, sulfur content was 0.53%, drum strength was 89.9%, abrasion resistance was 5.9%, thermal strength was 73.3%, and reactivity was 17.95%.

[0049] The specific components of the ingredients in the examples are shown in the table below:

[0050] Chemical composition of coking coal / %

[0051] Coal type <![CDATA[H2O]]> Ad <![CDATA[S tad ]]> <![CDATA[V daf ]]> G [S] Y b <![CDATA[R max ]]> Coking coal 1 11.19 11.05 0.51 23.54 89.80 0.18 16.56 73.21 1.33 Coking coal 2 11.77 10.10 1.13 22.76 84.56 0.19 15.00 19.90 1.40 coking coal 11.68 10.74 0.44 28.75 91.45 0.17 24.33 133.03 1.08 1 / 3 coking coal 9.63 6.49 0.27 36.84 86.14 0.17 15.20 36.62 0.86 lean coal 11.57 9.53 0.39 17.13 62.70 lean coal 12.28 10.00 0.32 15.38 26.18

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0053] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A coal blending method under low-load production conditions, characterized in that: It is prepared from the following raw materials by mass percentage: 30% coking coal, 27% fat coal, 18% 1 / 3 coking coal, 14% lean coal, and 11% semi-lean coal.

2. The coal blending method under low-load production conditions according to claim 1, characterized in that: The optimization steps are as follows: (1) Batching: The coal types in the coal mixing tank are mixed according to the set proportions; (2) Crushing: The blended coal is fed into a crusher and crushed to form blended coal; (3) Coking: The crushed blended coal is loaded into the coke oven through the coke oven charging hole for coking; (4) Quenching: The mature coke is cooled and discharged as finished coke through a dry quenching device.

3. The coal blending method under low-load production conditions according to claim 2, characterized in that: The performance indicators of the obtained coke are as follows: drum strength 89.5%, abrasion resistance 6.0%, thermal strength 71.1%, and reactivity 19.85%.

4. A coal blending method under low-load production conditions according to claim 2, characterized in that: In the crushing step, the various coal types are mixed evenly during the crushing process to ensure the uniformity and stability of the coal quality.

5. A coal blending method under low-load production conditions according to claim 2, characterized in that: In the coking process, mature coke is obtained after 38 hours of high-temperature dry distillation, with the standard temperature controlled at 1170℃ on the machine side and 1190℃ on the coke side.

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