CN112481432A

CN112481432A - Method for discharging lump coke in blast furnace

Info

Publication number: CN112481432A
Application number: CN202011274566.5A
Authority: CN
Inventors: 李壮年; 李宝峰; 武树永
Original assignee: Shanxi Taigang Stainless Steel Co Ltd
Current assignee: Shanxi Taigang Stainless Steel Co Ltd
Priority date: 2020-11-15
Filing date: 2020-11-15
Publication date: 2021-03-12
Anticipated expiration: 2040-11-15
Also published as: CN112481432B

Abstract

A method for discharging lump coke in a blast furnace comprises the following steps of (1) storing the lump coke in a No. 1 hopper at the near end of the blast furnace, and storing large coke in other hoppers; (2) when the discharging is started, the middle coke hopper and the large coke hopper discharge materials simultaneously, when the coke is weighed to the weight proportion of the set coke batch, the middle coke hopper stops discharging, and the large coke hopper continues discharging materials until the weight of the set coke batch is weighed; (3) when the medium lump coke accounts for less than 10.0% of the total coke amount, the medium lump coke accounts for 30% -40% of the total coke amount: when the medium coke accounts for 2.5 percent of the total coke amount, a 1# hopper is selected for 1 time; when the medium coke accounts for 5.0 percent of the total coke amount, a No. 1 hopper is selected for 2 times; (4) when the total coke content of the medium coke is required to be more than 10.0%, the No. 1 hopper is selected 4 times, and the proportion is set to be 60%. The invention reduces the coke in the middle to enter the central area, which is beneficial to keeping the smooth air flow in the center of the blast furnace and activating the furnace hearth.

Description

Method for discharging lump coke in blast furnace

Technical Field

The invention belongs to the field of blast furnace operation control.

Background

In recent years, with the increasingly competitive situation of the steel industry, various steel enterprises reduce the cost of raw fuel by various methods, and adopt a method of increasing medium coke to reduce the cost in the aspect of comprehensive utilization of coke. If the medium coke is mixed into the large coke and then charged into the blast furnace, the blast furnace has negative effects on the operation of the blast furnace: the middle coke and the large coke are mixed and loaded into the blast furnace, and the integral air permeability of the coke is reduced due to the mixing effect; the quality and the grain size difference of the large coke and the medium coke are large, the shapes of charge surfaces formed when the mixing effect is different are different, and particularly, the air flow in the center of the blast furnace is unstable, and the stability of the furnace condition is influenced.

After the medium coke enters the center of the blast furnace, the liquid permeability of dead material columns of the hearth can be influenced, and the activation of the hearth is not facilitated. Document "xuwanren, zhangyongyihong, etc. characterization and improvement approach of blast furnace hearth activity status [ J ] iron-making, 2010, 29 (3): 23-26 "the permeability of the dead mass column and the hearth activity depend mainly on the particle size of the core coke, the smaller the average particle size of the hearth coke, the more powder, the poorer the hearth permeability, so that the distribution of the medium coke to the central region of the blast furnace is to be avoided in order to ensure the hearth activity.

If the lump coke cannot be reasonably used, the activity and the airflow distribution of a blast furnace hearth can be influenced, but the stability and the smooth operation of the blast furnace are not facilitated, and the running cost of the blast furnace is reduced, so that a charging method for controlling the lump coke to enter the center of the blast furnace needs to be developed.

Coke hoppers under a blast furnace tank are usually 5-8, coke is discharged by adopting a dispersion screening and centralized weighing method, namely the selected hoppers discharge the material respectively when discharging the material, the coke is discharged to a coke belt and then weighed in a centralized manner, and the coke hoppers stop discharging the material when weighing to a set weight. The coke discharged firstly is a stub bar, the coke discharged secondly is a material tail, the coke finally enters the blast furnace through a coke belt, a main belt, a furnace top charging bucket and a discharging bucket, the stub bar firstly enters the blast furnace and is distributed to the edge position of the throat, and the material tail secondly enters the blast furnace and is distributed and rolled to the central position of the throat.

The coke can be classified into large coke and medium coke according to the particle size, the large coke is usually normal particle size coke, and the medium coke can be medium coke or coke.

The traditional discharging method comprises the following steps: the method for discharging the medium coke and the large coke has the defect that part of the medium coke enters the tail of the material and finally enters the central area of the blast furnace.

Disclosure of Invention

The invention provides a method for discharging lump coke in a blast furnace, which aims to effectively prevent the lump coke from entering the central area of the blast furnace.

A method for discharging lump coke in a blast furnace comprises the following steps:

(1) the coke hopper No. 1 at the near end of the blast furnace is internally provided with medium coke, and the other coke hoppers are used for storing large coke; 4 hopper selection modes (different coke hoppers can be selected respectively) are set in each period, the numbers are C1-C4, and 4 coke hoppers are selected for discharging each time;

(2) when the discharging is started, the middle coke hopper and the large coke hopper discharge materials simultaneously, when the coke is weighed to the weight proportion of the set coke batch, the middle coke hopper stops discharging, and the large coke hopper continues discharging materials until the weight of the set coke batch is weighed;

(3) when the total coke amount of the medium coke is required to be less than 10.0%, setting the proportion to be 30% -40%: when the amount of the medium coke in the total coke is required to be 2.5%, selecting a 1# coke hopper from C1-C4 for 1 time; when the amount of the medium coke accounts for 5.0 percent of the total coke, selecting a No. 1 coke hopper from C1-C4 for 2 times; when the coke in the coke blocks accounts for 7.5 percent of the total coke amount, selecting a No. 1 coke hopper from C1-C4 for 3 times; when the coke in the coke blocks accounts for 10.0 percent of the total coke amount, selecting a No. 1 coke hopper from C1-C4;

(4) when the total coke amount of the medium coke is required to be more than 10.0%, selecting a No. 1 coke hopper from C1-C4, and increasing the set proportion to meet the requirement; the proportion is usually set to not more than 60% to avoid a large amount of middle coke from entering the central region of the blast furnace.

In the test of the Tai-Steel 6# blast furnace, the invention effectively controls the middle coke to enter the central area of the blast furnace, is beneficial to keeping the smooth air flow of the center of the blast furnace, is beneficial to activating a hearth and plays an important role in the stability and smooth running of the blast furnace; meanwhile, the proper middle coke blocks are distributed on the edge of the blast furnace, and the whole granularity of the middle coke blocks is smaller, so that the control of edge airflow is facilitated, and the effects of stabilizing the edge airflow and heat load are achieved. In addition, the lump coke in a large amount of use not only can reduce the cost of per ton of iron pig iron, but also can solve the problem of production logistics balance.

After the new discharging method is adopted in 2019, the 6# blast furnace is continuously and stably operated, no furnace condition abnormality occurs, the blast furnace index is continuously and stably controlled at a better level, the fuel is reduced by about 6.5 kg/tFe in 2018 (wherein, the coal ratio is reduced from 153.5 kg/tFe to 144.6 kg/tFe, the coke ratio is increased from 352.5 kg/tFe to 353.8 kg/tFe), the coke price is about 1683 yuan/t, the coal dust price is about 813 yuan/t, the annual output of the 6# blast furnace is about 350 ten thousand tons, the technical contribution rate is 40 percent, namely the fuel ratio cost can be reduced annually:

[ (153.5-144.6) × 813+ (352.5-353.8) × 1683]/1000 × 350 × 40% =706.7 ten thousand yuan.

Detailed Description

Taking a Tai steel 6# blast furnace as an example:

(1) the 6# blast furnace is provided with 7 coke bins totally, wherein a coke hopper (1 #) at the near end of the blast furnace is internally provided with medium coke blocks (medium coke blocks), and other coke hoppers are used for storing large coke blocks (normal coke); 4 hopper selection modes (1-7 coke hoppers can be selected respectively) are set in each period, the numbers are C1-C4, and 4 coke hoppers are selected for discharging each time;

(3) when the total coke amount of the medium coke is required to be less than 10.0%, setting the proportion to be 30% -40%: when the amount of the medium coke in the total coke is required to be 2.5%, selecting a 1# coke hopper from C1-C4 for 1 time; when the amount of the medium coke accounts for 5.0 percent of the total coke, selecting a No. 1 coke hopper from C1-C4 for 2 times; by analogy, the using times of the coke hopper No. 1 are increased;

(4) when the coke in the medium coke accounts for more than 10.0 percent of the total coke, 1# coke buckets are selected from C1-C4, and the proportion is set to be 60 percent.

Claims

1. A method for discharging lump coke in a blast furnace is characterized by comprising the following steps:

(1) the 1# hopper at the near end of the blast furnace is internally provided with medium coke, and the other hoppers are used for storing large coke;

(3) when the medium lump coke accounts for less than 10.0% of the total coke amount, the medium lump coke accounts for 30% -40% of the total coke amount: when the medium coke accounts for 2.5 percent of the total coke, a 1# hopper is selected for discharging for 1 time; when the medium coke accounts for 5.0 percent of the total coke amount, a No. 1 hopper is selected for discharging for 2 times;

(4) when the total coke content of the medium coke is required to be more than 10.0%, 4 times of discharge of a No. 1 hopper is selected, and the proportion is set to be 60%.