CN112779037A

CN112779037A - Method for improving wear resistance of coke

Info

Publication number: CN112779037A
Application number: CN202110076286.1A
Authority: CN
Inventors: 贺佳; 史永林; 李昊堃; 刘文文; 赵建伟; 张春亮; 李波
Original assignee: Shanxi Taigang Stainless Steel Co Ltd
Current assignee: Shanxi Taigang Stainless Steel Co Ltd
Priority date: 2021-01-20
Filing date: 2021-01-20
Publication date: 2021-05-11
Anticipated expiration: 2041-01-20
Also published as: CN112779037B

Abstract

The invention provides a method for improving the wear resistance of coke, which comprises the following steps: mixing 10-15 wt% of lean coal, 5-10 wt% of 1/3 coking coal, 15-20 wt% of transitional fat coal, 5-10 wt% of fat coal and 50-55 wt% of coking coal to obtain blended coal; the blended coal is adopted to smelt coke. The method of the invention can obviously improve the wear resistance M of the coke₁₀Can be 4000m³And the blast furnace provides coke with high wear resistance, thereby creating conditions for reducing the coke ratio of the large blast furnace. Meanwhile, the utilization rate of coking coal resources is also increased, and the coal blending cost is reduced.

Description

Method for improving wear resistance of coke

Technical Field

The invention relates to the technical field of coal chemical industry, in particular to a method for improving the wear-resisting strength of coke.

Background

In recent years, with the rapid development of the coking industry in China, the demand of high-quality coking coal resources is increasing day by day, but the high-quality coking coal resources are in shortage day by day, so that the price of the high-quality coking coal resources is continuously increased, and the coal blending cost of coking enterprises is continuously increased. At the same time, 4350m³Blast furnace and 5500m³A batch of large blast furnaces represented by blast furnaces are put into operation in succession at home, and the large blast furnaces put higher requirements on the quality of coke, particularly the wear resistance M of the coke₁₀. Abrasion resistance M of coke₁₀Reflecting the coke's ability to resist external friction without surface peeling to form chips or powder. The test process of the index simulates the abrasion condition of coke in the blast furnace, between coke and coke, between coke and ore, between coke and the wall of the blast furnace, in the process of moving from top to bottom. Abrasion resistance M of coke₁₀Has important influence on the stable and smooth running of the blast furnace, and the abrasion resistance M of coke₁₀High, the gas permeability of the charge column in the blast furnace is poor, the production fluctuation of the blast furnace is large, and further the coke ratio and the utilization coefficient of the blast furnace are influenced.

The Chinese patent application with the application number of 201510559282.3 discloses a coal blending method for controlling the wear resistance of coke, which comprises the following steps: (1) controlling the quality of the gas fat coal and the fat coal; (2) dividing the coking coal with weak caking property into coking coal with low metamorphism and weak caking coal with high metamorphism; (3) different coal blending systems are selected according to the blending amount of the low-metamorphic weak caking coking coal being more than 10 percent or less than or equal to 10 percent. However, among them, low-rank, high-rank, low-viscosity coal is actually gas coal and lean coal. The coal blending scheme of the patent application can lead to the increase of the volatile components of the blended coal, and the abrasion resistance M of the coke cannot be greatly improved₁₀. Furthermore, the increase in volatiles leads to an increase in cracking of the coke, resulting in a coke crushing strength M₄₀And (4) descending. In addition, the coal blending scheme of the patent application has high cost and is not beneficial to practical production and application. In addition, the coke quality cannot satisfy 4000m³The use requirements of large blast furnaces of grade and above.

The Chinese patent application with the application number of 201010600693.X discloses a coking and coal blending method, which adopts a coal blending system comprising the following steps:1-5% of gas-fat coal, 5-15% of fat coal, 25-35% of 1/3 coking coal with dry ash-free volatile component more than 29%, 3-10% of Indonesian coal, 25-35% of coking coal with dry ash-free volatile component less than 27% and 10-15% of lean coal. However, since a large proportion of 1/3 coking coal with high volatile matter and a certain amount of gas fat coal are blended, the volatile matter of the blended coal is high, and the shrinkage of the blended coal is large, so that the cold and hot strength of the coke cannot be improved. The coke quality can not meet 4000m³The use requirements of large blast furnaces of grade and above.

The Chinese patent application with the application number of 201410067852.2 discloses a coal blending method for refining coking coal with high volatile content in a large proportion, which adopts a coal blending system that: 15-20% of gas coal, 27-30% of 1/3 coking coal, 10-16% of fat coal, 26-29% of coking coal and 10-15% of lean coal, wherein the sum of the weight percentages of the above coal is 100%, the sum of the gas coal in the blended coal and the 1/3 coking coal is more than or equal to 40%, and the blending ratio of the coking coal in the blended coal is less than 30%. However, because a large proportion of 1/3 coking coal with high volatile matter and a certain amount of gas coal are mixed, the volatile matter of the mixed coal is very high, basically more than 30 percent, the shrinkage of the mixed coal is very large, and the cold and hot states of coke are not very high. The coke quality can not meet 4000m³The use requirements of large blast furnaces of grade and above.

In general, no method for effectively improving the wear resistance of the coke exists at present.

Disclosure of Invention

In order to solve all or part of the above problems, the present invention aims to provide a method for improving the abrasion resistance of coke.

The invention realizes the above purposes by the following technical scheme:

a method of increasing the attrition resistance of coke comprising: mixing 10-15 wt% of lean coal, 5-10 wt% of 1/3 coking coal, 15-20 wt% of transitional fat coal, 5-10 wt% of fat coal and 50-55 wt% of coking coal to obtain blended coal; the blended coal is adopted to smelt coke.

Optionally, the transition fat coal: dry ashless based volatile V_dafNot more than 25%, the bonding index G is not less than 90, and the average value of the maximum reflectivity of the vitrinite

The standard deviation S of the vitrinite reflectivity is less than or equal to 0.15 percent.

Optionally, the lean coal: dry ashless based volatile V_dafLess than or equal to 16 percent, and the bonding index G is more than or equal to 25.

Alternatively, the 1/3 coking coal: dry ashless based volatile V_dafLess than or equal to 33 percent, and the bonding index G is more than or equal to 85.

Alternatively, the fat coal: dry ashless based volatile V_dafLess than or equal to 31 percent and the bonding index G is more than or equal to 90.

Optionally, the coking coal: dry ashless based volatile V_dafLess than or equal to 22 percent and the bonding index G is more than or equal to 85.

Optionally, the blended coal: dry ashless based volatile V_dafLess than or equal to 24 percent, the bonding index G is more than or equal to 78 percent, and the water content is 9.0 to 9.5 weight percent.

Optionally, the step of smelting coke by using the blended coal adopts a coking heating system that: the coking time is 25.5-32 hours, and the standard temperature is 1265-1330 ℃; the coke quenching mode is dry coke quenching.

According to the technical scheme, the method for improving the wear resistance of the coke has the following advantages:

the method of the invention can obviously improve the wear resistance M of the coke₁₀Can be 4000m³And the blast furnace provides coke with high wear resistance, thereby creating conditions for reducing the coke ratio of the large blast furnace. Meanwhile, the utilization rate of coking coal resources is also increased, and the coal blending cost of coking enterprises is reduced.

Drawings

FIG. 1 is a vitrinite maximum reflectance distribution diagram of the transition fat coal in the example.

FIG. 2 is a vitrinite maximum reflectance distribution diagram of the fat coal in the example.

Detailed Description

The present invention will be described in detail with reference to the following embodiments in order to fully understand the objects, features and effects of the invention. The process of the present invention employs conventional methods or apparatus in the art, except as described below.

Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. For example, the following references provide the person skilled in the art with a basic guidance on the technical terms used in the present invention: "coal chemistry", metallurgical industry press, second edition, 2010; chinese coal Classification Standard GB/T5751-2009; chinese coal classification summary, 1989; maishichang, dictionary of chemical substances, Shanxi science and technology Press, 1999; lincong, encyclopedia of metallurgy of China, Metallurgical Press, 1998.

The invention particularly adopts transitional fat coal. The transitional coal type is a 'mixed coal' formed by two adjacent coals with different coal grades, and is characterized in that the coal type is divided according to process properties, and the brand of the coal type is a certain coal type. The coal rank (brand) is another coal according to the reflectivity of the vitrinite body of the coal rock, and the coal quality has the process property of two adjacent coals with different coal ranks or more approaches to the process property of a certain coal rank. The transitional fat coal adopted by the invention is divided according to the process property, the grade is fat coal, the grade is divided according to the reflectivity of the vitrinite body of the coal rock, and the coal rank (grade) is coking coal.

According to the classification standard of Chinese coal classification standard GB/T5751-2009, transitional fat coal V_dafThe content of the transition fat coal is 20.0-28.0, the G value is more than or equal to 85, the Y value is more than 25, and the transition fat coal belongs to 26-coded fat coal. The frequency of the vitrinite maximum reflectance value in the interval of 1.2% -1.5% is 63.3%, the most of the metamorphic grade is V, and the coking coal is judged. The process property of the transitional fat coal used by the invention is the properties of both fat coal and coking coal.

Currently, gas coal, gas fat coal or some weak caking coking coal is usually adopted in the coal blending process in the coking process. However, the inventor of the present invention found through research that gas coal, gas fat coal or some coking coal with weak caking property have high volatile components, low degree of coalification and poor coking property, and the blended coal has high volatile components and large shrinkage after blending. After the coal is heated by isolating air, the formed semicoke layer becomes thin, the semicoke shrinkage is large, more gaseous products are still separated out when the semicoke is solidified, the semicoke porosity is increased, the strength is reduced, the capability of resisting thermal polycondensation in and between layers is low, and more cracks are generated. The cold strength of the coke is not very high.

In order to solve the problems, the inventor of the invention researches and improves the single coal type of the blended coal, the content ratio of each single coal and the coking system, thereby creatively providing a method for improving the abrasion resistance of the coke. The problems caused by adopting gas coal, gas fat coal or certain coking coal with weak caking property and the like can be solved by using the transitional fat coal with low volatile content and excellent coking property and using the blended coal with low volatile content after blending.

The method for improving the wear resistance of the coke specifically comprises the following steps:

(1) preparing the blended coal

Mixing 10-15 wt% of lean coal, 5-10 wt% of 1/3 coking coal, 15-20 wt% of transitional fat coal, 5-10 wt% of fat coal and 50-55 wt% of coking coal to obtain blended coal.

The single coal adopted by the invention has the following properties:

transition fat coal: dry ashless based volatile V_dafNot more than 25%, the bonding index G is not less than 90, and the average value of the maximum reflectivity of the vitrinite

Lean coal: dry ashless based volatile V_dafLess than or equal to 16 percent, and the bonding index G is more than or equal to 25.

1/3 coking coal: dry ashless based volatile V_dafLess than or equal to 33 percent, and the bonding index G is more than or equal to 85.

Coal fertilizing: dry ashless based volatile V_dafLess than or equal to 31 percent and the bonding index G is more than or equal to 90.

Coking coal: dry ashless based volatile V_dafLess than or equal to 22 percent and the bonding index G is more than or equal to 85.

The dry ash-free base volatile matter V of the blended coal is obtained by mixing the single coals according to the proportion_dafLess than or equal to 24 percent, the bonding index G is more than or equal to 78 percent, and the water content is 9 percent.0～9.5wt％。

(2) Coking

The blended coal smelting coke obtained in the step (1) is specially provided with a coking heating system matched with a coal blending scheme, and specifically comprises the following steps: the coking time is 25.5-32 hours, the standard temperature is 1265-1330 ℃, and the coke quenching mode is dry coke quenching.

In the invention, by adding transitional fat coal and combining the transitional fat coal with other coal types according to a specific proportion, on one hand, the coke blocks can be more compact and the wear-resisting strength of the coke can be improved, and on the other hand, the capability of resisting the thermal polycondensation in and between layers of the mixed coal can be improved, so that the cracks generated by the coke are less, and the cold strength of the coke is improved.

In addition, the invention also adopts a coking heating system matched with the coal blending scheme, and avoids coking caused by non-volatilization of a large amount of residual volatile components in the coke or increased cracks of coke cakes due to over-maturity of the coke by controlling the moisture and volatile components of the blended coal, thereby being beneficial to improving the coke strength, shortening the coking time, improving the smelting strength and increasing the discharge number.

In the present invention, each of the above-mentioned individual coals is commercially available, and the present invention has no particular requirement for each individual coal other than the above-mentioned ones.

Examples

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.

The detection methods employed in the following examples:

crushing strength M₄₀And abrasion resistance M₁₀: the method for measuring the mechanical strength of the coke is in accordance with GB/T2006-2008.

The transition fat coal and fat coal quality analyses used in the following examples are shown in table 1:

TABLE 1

The vitrinite maximum reflectance analysis of the transitional and fat coals used in the following examples is shown in table 2:

TABLE 2

The vitrinite maximum reflectance profiles of the transition fat coal and the fat coal used in the following examples are shown in fig. 1 and 2, respectively.

The coal quality analyses of the lean coal, 1/3 coking coal and coking coal used in the following examples are shown in Table 3:

TABLE 3

Example 1

In this example, a 7.63m coke oven was used. The process of this example is as follows:

(1) mixing 50 wt% of coking coal, 15 wt% of transitional fat coal, 10 wt% of 1/3 coking coal and 15 wt% of lean coal to obtain blended coal, wherein the indexes of the blended coal are as follows: v of blended coal_daf23.6 percent, the caking index G value of the blended coal is 78, and the moisture content of the blended coal is 9.3 percent by weight.

(2) Coking, a coking heating system: the coking time is 31.5h, and the standard temperature is 1265 ℃. The coke quenching mode is dry coke quenching.

The coke strength obtained in this example is: crushing strength M₄₀A value of 89.8%, abrasion resistance M₁₀The value was 4.7%.

Example 2

(1) mixing 55 wt% of coking coal, 15 wt% of transitional fat coal, 5 wt% of fat coal, 10 wt% of 1/3 coking coal and 15 wt% of lean coal to obtain blended coal, wherein the indexes of the blended coal are as follows: v of blended coal_daf23.2%, and the caking index G of the blended coal was78, the water content of the blended coal is 9.4 wt%.

(2) Coking, a coking heating system: the coking time is 30.5h, and the standard temperature is 1275 ℃. The coke quenching mode is dry coke quenching.

The coke strength obtained in this example is: crushing strength M₄₀A value of 89.9%, abrasion resistance M₁₀The value was 4.7%.

Example 3

(1) mixing 52 wt% of coking coal, 17 wt% of transitional fat coal, 8 wt% of fat coal, 9 wt% of 1/3 coking coal and 14 wt% of lean coal to obtain blended coal, wherein the indexes of the blended coal are as follows: v of blended coal_daf23.4%, the caking index G of the blended coal was 78, and the moisture of the blended coal was 9.2 wt%.

(2) Coking, a coking heating system: the coking time is 29.5h, and the standard temperature is 1285 ℃. The coke quenching mode is dry coke quenching.

The coke strength obtained in this example is: crushing strength M₄₀A value of 89.6%, abrasion resistance M₁₀The value was 4.8%.

Example 4

(1) mixing 50 wt% of coking coal, 20 wt% of transitional fat coal, 10 wt% of 1/3 coking coal and 10 wt% of lean coal to obtain blended coal, wherein the indexes of the blended coal are as follows: v of blended coal_daf24.0 percent, the caking index G value of the blended coal is 79, and the moisture content of the blended coal is 9.0 percent by weight.

(2) Coking, a coking heating system: the coking time is 26.5h, and the standard temperature is 1315 ℃. The coke quenching mode is dry coke quenching.

The coke strength obtained in this example is: crushing strength M₄₀A value of 89.5%, abrasion resistance M₁₀The value was 4.9%.

Example 5

(1) 55 wt% of coking coal, 20 wt% of transitional fat coal, 5 wt% of fat coal and 1/3 cokeMixing 5 wt% of coal and 15 wt% of lean coal to obtain blended coal, wherein the indexes of the blended coal are as follows: v of blended coal_daf22.7 percent, the caking index G value of the blended coal is 79, and the moisture content of the blended coal is 9.2 percent by weight.

(2) Coking, a coking heating system: the coking time is 25.5h, and the standard temperature is 1325 ℃. The coke quenching mode is dry coke quenching.

The coke strength obtained in this example is: crushing strength M₄₀A value of 89.6%, abrasion resistance M₁₀The value was 4.9%.

Example 6

(1) mixing 54 wt% of coking coal, 19 wt% of transitional fat coal, 6 wt% of fat coal, 8 wt% of 1/3 coking coal and 13 wt% of lean coal to obtain blended coal, wherein the indexes of the blended coal are as follows: v of blended coal_daf23.2 percent, the caking index G value of the blended coal is 80, and the water content of the blended coal is 9.3 percent by weight.

(2) Coking, a coking heating system: the coking time was 27.5h and the standard temperature was 1305 ℃. The coke quenching mode is dry coke quenching.

The coke strength obtained in this example is: crushing strength M₄₀Value of 90.0%, abrasion resistance M₁₀The value was 4.6%.

Example 7

(1) mixing 55 wt% of coking coal, 20 wt% of transitional fat coal, 5 wt% of fat coal, 8 wt% of 1/3 coking coal and 12 wt% of lean coal to obtain blended coal, wherein the indexes of the blended coal are as follows: v of blended coal_daf23.1 percent, the caking index G value of the blended coal is 80, and the water content of the blended coal is 9.1 percent by weight.

(2) Coking, a coking heating system: the coking time is 25.5h, and the standard temperature is 1295 ℃. The coke quenching mode is dry coke quenching.

The coke strength obtained in this example is: crushing strength M₄₀A value of 90.2%, abrasion resistance M₁₀The value was 4.6%.

Comparative example 1

The comparative example used a 7.63m coke oven, the process was as follows:

(1) mixing 48 wt% of coking coal, 30 wt% of fat coal, 9 wt% of 1/3 coking coal and 13 wt% of lean coal to obtain blended coal, wherein the indexes of the blended coal are as follows: v of blended coal_daf24.9%, the caking index G of the blended coal was 78, and the moisture of the blended coal was 9.3 wt%.

(2) Coking, a coking heating system: the coking time is 26h, and the standard temperature is 1310 ℃. The coke quenching mode is dry coke quenching.

The coke strength obtained in this example is: crushing strength M₄₀Value of 88%, abrasion resistance M₁₀The value was 6.5%.

Comparative example 2

The comparative example used a 7.63m coke oven, the process was as follows:

(1) mixing 50 wt% of coking coal, 10 wt% of transitional fat coal, 15 wt% of fat coal, 10 wt% of 1/3 coking coal and 15 wt% of lean coal to obtain blended coal, wherein the indexes of the blended coal are as follows: v of blended coal_daf24.2 percent, the caking index G value of the blended coal is 75, and the water content of the blended coal is 9.8 percent by weight.

The coke strength obtained in this example is: crushing strength M₄₀A value of 89.1%, abrasion resistance M₁₀The value was 5.8%.

Comparative example 3

The comparative example used a 7.63m coke oven, the process was as follows:

(1) mixing 50 wt% of coking coal, 25 wt% of transitional fat coal, 5 wt% of fat coal, 6 wt% of 1/3 coking coal and 14 wt% of lean coal to obtain blended coal, wherein the indexes of the blended coal are as follows: v of blended coal_daf23.5%, the caking index G of the blended coal was 77, and the moisture of the blended coal was 10.3 wt%.

The coke strength obtained in this example is: crushing strength M₄₀Value of 88.7%, abrasion resistance M₁₀The value was 6.1%.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other substitutions, modifications, combinations, changes, simplifications, etc., which are made without departing from the spirit and principle of the present invention, should be construed as equivalents and included in the protection scope of the present invention.

Claims

1. A method for improving the abrasion resistance of coke, comprising:

mixing 10-15 wt% of lean coal, 5-10 wt% of 1/3 coking coal, 15-20 wt% of transitional fat coal, 5-10 wt% of fat coal and 50-55 wt% of coking coal to obtain blended coal;

the blended coal is adopted to smelt coke.

2. The method for improving coke abrasion resistance according to claim 1, wherein the transition fat coal: dry ashless based volatile V_dafNot more than 25%, the bonding index G is not less than 90, and the average value of the maximum reflectivity of the vitrinite

3. The method for improving the abrasion resistance of coke according to claim 1, wherein the lean coal: dry ashless based volatile V_dafLess than or equal to 16 percent, and the bonding index G is more than or equal to 25.

4. The method for improving the attrition strength of coke of claim 1 wherein the 1/3 coking coal: dry ashless based volatile V_dafLess than or equal to 33 percent, and the bonding index G is more than or equal to 85.

5. The method of increasing coke attrition resistance of claim 1 wherein the fat coal: dry ashless based volatile V_dafLess than or equal to 31 percent and the bonding index G is more than or equal to 90.

6. According toThe method of increasing the attrition resistance of coke of claim 1 wherein the coking coal: dry ashless based volatile V_dafLess than or equal to 22 percent and the bonding index G is more than or equal to 85.

7. The method for improving coke abrasion resistance according to claim 1, wherein the blended coal: dry ashless based volatile V_dafLess than or equal to 24 percent, the bonding index G is more than or equal to 78 percent, and the water content is 9.0 to 9.5 weight percent.

8. The method for improving the abrasion resistance of the coke according to claim 1, wherein the step of smelting the coke by using the blended coal adopts a coking heating system comprising: the coking time is 25.5-32 hours, and the standard temperature is 1265-1330 ℃; the coke quenching mode is dry coke quenching.