阅读说明：本技术 一种高比例球团抽焦的布料方法 (Material distribution method for high-proportion pellet coke extraction ) 是由 姜喆 朱建伟 郭天永 车玉满 姚硕 张延辉 谢明辉 邵思维 曾宇 张磊 于 2021-07-16 设计创作，主要内容包括：本发明涉及一种高比例球团抽焦的布料方法,包括控制矿批中球团比例、采用无料钟多环布料方式向高炉中布料,每次布料时抽取焦炭批重的4％～6％,每布5～20批料后,将这些抽取的焦炭单独布到高炉中心等措施；本发明能够避免因球团比例提高造成高炉炉喉料面不稳定的情况发生,解决了由于球团易滚动造成高炉气流不稳的问题,同时提高了高炉的经济技术指标。(The invention relates to a material distribution method for high-proportion pellet coke extraction, which comprises the steps of controlling the pellet proportion in an ore batch, distributing materials into a blast furnace in a bell-less multi-ring material distribution mode, extracting 4-6% of the weight of a coke batch during material distribution, distributing the extracted coke to the center of the blast furnace independently after distributing 5-20 batches, and the like; the invention can avoid the unstable condition of the blast furnace throat charge level caused by the increased proportion of the pellets, solve the problem of unstable blast furnace gas flow caused by easy rolling of the pellets, and simultaneously improve the economic and technical indexes of the blast furnace.)

1. A material distribution method for high-proportion pellet coke extraction is characterized by comprising the following steps:

1) controlling the proportion of the pellets in the ore batch to be 30-100 percent;

2) distributing the material into the blast furnace in a bell-less multi-ring distribution mode, extracting 4-6% of the batch weight of the coke during each distribution, and independently distributing the extracted coke to the center of the blast furnace after each distribution of 5-20 batches;

3) distributing coke accounting for 10-20% of the weight of the coke batch to an outermost ring;

4) performing secondary central coking on each batch of coke according to 20-30% of the batch weight of the coke to form 'ore blocking coke';

5) controlling the inclination angle of the outermost ring of the ore to be 1-2 degrees smaller than the inclination angle of the outermost ring of the coke;

6) the feeding sequence of the ore batch on the feeding belt is as follows: sintered ore or flux, pellet;

7) controlling the difference between the angle of the outermost ring chute of the coke and the angle of the inclination angle of the secondary central chute to be 10-15 degrees, and controlling the difference between the angle of the outermost ring and the angle of the innermost ring of the ore to be 10-15 degrees; the widths of the coke terrace and the ore terrace formed at the furnace throat are greater than 1/3 and less than 2/3 of the radius of the furnace throat.

2. The burden distribution method for high-proportion pellet coke extraction as claimed in claim 1, wherein in the process 2), when coke is independently added to the center of the blast furnace, the inclination angle of the chute for coke conveying is controlled within 10 degrees.

Technical Field

The invention relates to the technical field of blast furnace material distribution, in particular to a material distribution method for high-proportion pellet coke extraction.

Background

The method has the advantages of improving the proportion of the pellets in the blast furnace burden, improving the iron-containing grade of the charged ore, reducing the ore amount per ton of iron, reducing the fuel ratio, increasing the yield, reducing the pollutant emission, promoting the energy conservation and emission reduction of an iron-making system, reducing the flue gas treatment cost of the agglomeration process, and simultaneously being an important measure for realizing the reduction and the minimum dissipation of the blast furnace production. Along with the stricter and stricter national environmental protection requirements, the pollution of the sinter production to the environment is more and more emphasized, and along with the improvement of the pellet production capacity of the domestic steel plant, the progress of the iron-making technology and the environmental protection pressure, the high-proportion pellet blast furnace smelting becomes the development trend of the blast furnace iron-making in China. However, as the pellets have the characteristics of small average particle size, uniform particle size, easy rolling, small natural stacking angle (only 24-27 °), and the like, more and more pellets will roll towards the center and the edge under the same distribution angle and distribution mode conditions with the improvement of the pellet proportion, so that two gas flows at the center and the edge of the blast furnace are gradually weakened, the pressure difference of the blast furnace is increased, the air permeability is deteriorated, and finally the negative influence is brought to the economic index of the blast furnace.

The chinese patent with patent application number 201510172312.5 discloses a method for distributing blast furnace pellets, which reasonably divides a large proportion of pellets by using different characteristics of blast furnace raw materials used by a blast furnace, so that the pellets no longer have 'fluidity' when used in a large proportion, thereby thoroughly solving the problem of unstable charge level in the blast furnace after the pellets are used in a high proportion, further stabilizing the upper airflow of the blast furnace, improving the utilization rate of blast furnace gas and reducing the production cost. However, the method needs to carry out discharging and feeding according to the manner of 'sinter + pellet + sinter + pellet …', so that the process is complex, and the operation difficulty is greatly increased.

Disclosure of Invention

The invention provides a material distribution method for high-proportion pellet coke extraction, which can avoid the occurrence of unstable charge level of a blast furnace throat caused by the increase of pellet proportion, solve the problem of unstable blast furnace gas flow caused by easy rolling of pellets, and simultaneously improve the economic and technical indexes of a blast furnace.

In order to achieve the purpose, the invention adopts the following technical scheme:

a material distribution method for high-proportion pellet coke extraction comprises the following steps:

1) controlling the proportion of the pellets in the ore batch to be 30-100 percent;

2) distributing the material into the blast furnace in a bell-less multi-ring distribution mode, extracting 4-6% of the batch weight of the coke during each distribution, and independently distributing the extracted coke to the center of the blast furnace after each distribution of 5-20 batches;

3) distributing coke accounting for 10-20% of the weight of the coke batch to an outermost ring;

4) performing secondary central coking on each batch of coke according to 20-30% of the batch weight of the coke to form 'ore blocking coke';

5) controlling the inclination angle of the outermost ring of the ore to be 1-2 degrees smaller than the inclination angle of the outermost ring of the coke;

6) the feeding sequence of the ore batch on the feeding belt is as follows: sintered ore or flux, pellet;

7) controlling the difference between the angle of the outermost ring chute of the coke and the angle of the inclination angle of the secondary central chute to be 10-15 degrees, and controlling the difference between the angle of the outermost ring and the angle of the innermost ring of the ore to be 10-15 degrees; the widths of the coke terrace and the ore terrace formed at the furnace throat are greater than 1/3 and less than 2/3 of the radius of the furnace throat.

In the process 2), when the coke is independently added to the center of the blast furnace, the inclination angle of the chute for coke conveying is controlled within 10 degrees.

Compared with the prior art, the invention has the beneficial effects that:

1) when the high-proportion pellets of the blast furnace are smelted, the rolling effect of the pellets in the blast furnace can be effectively controlled, the stability of two air flows at the edge and the center in the furnace is facilitated, the reasonable operation furnace shape is controlled, and the stable and smooth smelting of the blast furnace is ensured;

2) the blast furnace burden distribution method has strong operability and simple process;

3) the central coke adding proportion is low, the coal gas utilization rate can be effectively improved, the fuel consumption is reduced, and the purposes of energy conservation and emission reduction are achieved.

Detailed Description

The invention relates to a material distribution method for high-proportion pellet coke extraction, which comprises the following steps:

1) controlling the proportion of the pellets in the ore batch to be 30-100 percent;

2) distributing the material into the blast furnace in a bell-less multi-ring distribution mode, extracting 4-6% of the batch weight of the coke during each distribution, and independently distributing the extracted coke to the center of the blast furnace after each distribution of 5-20 batches;

3) distributing coke accounting for 10-20% of the weight of the coke batch to an outermost ring;

4) performing secondary central coking on each batch of coke according to 20-30% of the batch weight of the coke to form 'ore blocking coke';

5) controlling the inclination angle of the outermost ring of the ore to be 1-2 degrees smaller than the inclination angle of the outermost ring of the coke;

6) the feeding sequence of the ore batch on the feeding belt is as follows: sintered ore or flux, pellet;

7) controlling the difference between the angle of the outermost ring chute of the coke and the angle of the inclination angle of the secondary central chute to be 10-15 degrees, and controlling the difference between the angle of the outermost ring and the angle of the innermost ring of the ore to be 10-15 degrees; the widths of the coke terrace and the ore terrace formed at the furnace throat are greater than 1/3 and less than 2/3 of the radius of the furnace throat.

In the process 2), when the coke is independently added to the center of the blast furnace, the inclination angle of the chute for coke conveying is controlled within 10 degrees.

In the invention, the inclination angle of the outermost ring of the coke distributed by the blast furnace is controlled to be slightly larger than the limit angle of the outermost ring by 0.2-0.5 degrees, so that the coke is controlled to firstly touch the furnace wall and then fall onto the material surface of the furnace throat in the process of falling from a chute to the material surface, and 10-20 percent of the weight of the coke batch is distributed to the outermost ring, thereby ensuring the stability of the edge airflow of the blast furnace.

And performing secondary center coke addition on each batch according to 20-30% of the batch weight of coke to form 'ore blocking coke', and ensuring that the pellets cannot roll towards the center of the furnace throat.

Controlling the inclination angle of the outermost ring of the ore to be 1-2 degrees smaller than the inclination angle of the outermost ring of the coke, and avoiding the pellet from contacting the blast furnace wall; the feeding sequence of the ore batch on the large belt is as follows: sinter (or flux), pellets, ensure the position of the pellets in the furnace far from the edge of the furnace wall.

The following examples are carried out on the premise of the technical scheme of the invention, and detailed embodiments and specific operation processes are given, but the scope of the invention is not limited to the following examples.

[ example 1 ]

In a certain steelworks 2580m³For example, the blast furnace uses 70% pellet + 30% sinter as the iron-making raw material. The ironmaking raw fuel used in the present example has the following batch weights: coke batch weight 14 t; the ore batch weight is 68t (wherein the mass of the sintered ore is 20.4t, and the mass of the pellet ore is 47.6 t).

When the ore is loaded, the discharging sequence of the ore tank on the loading belt is controlled as follows: the sintered ore and the pellet ensure that the sintered ore falls into the bottom of the charging bucket, and the sintered ore can be distributed to the edge of the blast furnace during distribution.

Extracting 5 percent of the normal batch weight of each batch of coke, namely 0.7t for standby;

controlling the outermost ring angle of the coke to be 43.3 degrees (0.3 degrees larger than the limit angle of the coke on the outermost ring of the blast furnace by 43 degrees); controlling the difference between the angle of the outermost ring chute of the coke distribution and the inclination angle of the secondary center chute to be 14.2 degrees; the inclination angle of the chute at the outermost ring of coke distribution is 1.6 degrees larger than that of the chute at the outermost ring of ore.

The difference between the outermost ring angle and the innermost ring angle of the ore is controlled to be 12.6 degrees.

2 circles of coke are distributed on the outermost ring (the 11 th ring position in the embodiment) and account for 13.3 percent of the coke weight; in the secondary central part (5 th ring position in the embodiment), 3 circles of coke are distributed, and the coke accounts for 20 percent of the batch weight.

In this example, the blast furnace burden distribution matrix is shown in table 1:

TABLE 1

Gear position	11	10	9	8	7	6	5	4	3	2	1	Batch weight
													Angle of rotation	43.3°	41.7°	39.5°	37.1°	34.6°	31.9°	29.1°	29.0°	22.3°	15.0°	10.0°	-
Mine	-	2	3	2	2	2	2	-	-	-	-	68 ton of
													Coke (coke)	2	2	2	2	2	2	3	-	-	-	-	13.3 ton

After each 20 batches of the coke are distributed, the coke extracted in the front is distributed into the center of the blast furnace in a clean coke form as a central coke; the matrix of the blast furnace center plus clean coke is shown in table 2:

TABLE 2

Gear position	11	10	9	8	7	6	5	4	3	2	1
												Angle of rotation	43.3°	41.7°	39.5°	37.1°	34.6°	31.9°	29.1°	29.0°	22.3°	15.0°	10.0°
Coke (coke)	0	0	0	0	0	0	0	-	-	-	14 ton of

In the embodiment, the method is adopted to carry out high-proportion pellet distribution, the continuous production lasts for 180 days, the charge level and the gas flow of the blast furnace are stable, the thermal load of the furnace body of the blast furnace does not fluctuate obviously, the blast furnace runs stably and smoothly, and the economic and technical indexes of the blast furnace are improved obviously.

[ example 2 ]

This example uses a Steel works 3200m³For example, the blast furnace uses 100% pellet + 0% sinter as the raw materials for iron making. The iron-making raw fuel used in the embodiment has the following batch weights: coke batch weight 17 t; the ore batch weight is 90t, and all are pellets.

When the ore is loaded, the discharging sequence of the ore tank on the belt is controlled as follows: fusing agent and pellet ore, ensuring the fusing agent to fall into the bottom of the ore tank, and distributing the fusing agent to the edge of the blast furnace.

And extracting 5 percent of the normal batch weight of each batch of coke, namely 0.85t for standby.

Controlling the outermost ring angle of the coke to be 42.2 degrees (0.2 degrees larger than the limit angle 42 degrees of the outermost ring coke of the blast furnace); controlling the difference between the angle of the outermost ring chute of the coke distribution and the inclination angle of the secondary center chute to be 13.3 degrees; the inclination angle of the chute at the outermost ring of coke distribution is 1 degree larger than that of the chute at the outermost ring of ore.

The difference between the outermost ring angle and the innermost ring angle of the ore is controlled to be 12.3 degrees.

3 circles of coke are distributed on the outermost ring (the 11 th ring position in the embodiment) and account for 17.6 percent of the coke batch weight; in the secondary central part (5 th ring position in the embodiment), 3 circles of coke are distributed, and the coke accounts for 20 percent of the batch weight.

The matrix when the blast furnace normally distributes materials is shown in table 3:

TABLE 3

Gear position	11	10	9	8	7	6	5	4	3	2	1	Batch weight
													Angle of rotation	42.2°	41.2°	39°	36.7°	34.3°	31.7°	28.9°	25.9°	22.9°	17.2°	13.0°	-
Mine	-	2	3	2	2	2	2	-	-	-	-	90 ton of
													Coke (coke)	3	2	2	2	2	2	4	-	-	-	-	-

After each 10 batches, the previously extracted coke was distributed as a central coke in the form of a clean coke into the center of the blast furnace.

The matrix for blast furnace center plus clean coke is shown in table 4:

TABLE 4

Gear position	11	10	9	8	7	6	5	4	3	2	1
												Angle of rotation	42.2°	41.2°	39°	36.7°	34.3°	31.7°	28.9°	25.9°	22.9°	17.2°	13.0°
Coke (coke)	0	0	0	0	0	0	0	-	-	-	8.5 ton

In the embodiment, 3200m is obtained after high-proportion pellet distribution by adopting the method disclosed by the invention³The blast furnace can be continuously produced for 30 days, the charge level and the gas flow of the blast furnace are stable, the heat load of the furnace body of the blast furnace is not obviously fluctuated, and the blast furnace is stable and smooth.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.