CN-122012827-A - Method for improving blast furnace damping down material loading process and initial gas utilization rate of air supply

CN122012827ACN 122012827 ACN122012827 ACN 122012827ACN-122012827-A

Abstract

The invention relates to a blast furnace ironmaking technology, in particular to a method for improving the gas utilization rate in the blast furnace damping down material loading process and the initial air supply period, aiming at the phenomenon that the gas utilization rate is reduced by 4% -5% due to the increase of coke consumption in the blast furnace damping down material loading process and the initial air supply recovery period before long-term damping down, the distribution of gas flow in a material column is improved and optimized by adjusting the distribution mode of damping down materials, the top material distribution matrix, the air supply recovery speed and other parameters, the conditions of the gas and ore contact and reaction are improved, the minimum value of the gas utilization rate is improved to more than 44% from 42%, the average value is improved to more than 46%, the indirect reduction degree of the ore is increased, the fuel consumption is reduced, and the smooth recovery of the furnace condition is promoted.

Inventors

ZHAO XUEBIN
LI ZHUANGNIAN
SONG JIANZHONG
TANG SHUNBING
WU SHUYONG
WANG ZHAOHUI
YAN BIN
SHI QING
GONG LIWEI
ZHANG ZHI

Assignees

山西太钢不锈钢股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260206

Claims (2)

1. The method for improving the utilization rate of the blast furnace damping down material in the loading process and the initial gas in the air supply stage is characterized by comprising the following steps: firstly, maintaining the weight of ore batches unchanged in two smelting periods before blowing down of a blast furnace, and increasing 10kg/t on the basis of normal production coke ratio by increasing coke charge, wherein the normal coke ratio is determined according to the actual condition of the blast furnace operation, and the range is 320-360 kg/t; Determining a basic coke ratio of a damping down material according to the damping down time by using a formula (1), wherein the basic coke ratio of the damping down material is K Damping material ＝K Normal material ＋h When the user is on a break multiplied by 1.0 (1), the coke ratio of the damping down material is K Damping material , the coke ratio of the damping down material is kg/t, the coke ratio of the damping down material is K Normal material , the coke ratio of the damping down material is normal, the coke ratio of the damping down material is kg/t, h Duration of damping down , the number of hours from the start of the damping down to the re-blowing down is planned, h is increased by 1h, the coke ratio of the damping down material of the whole furnace is increased by 1.0kg/t, damping down materials with the coke ratio of K Damping material are filled in a smelting period before the damping down until the damping down is carried out, the weight of the damping down materials is consistent with the weight of ore batches in normal production, and the weight of the ore batches in normal production is 40-180 t; Adding the empty coke according to the length of the blowing-down time, and calculating the number n Empty coke of the empty coke according to a formula (2), wherein n Empty coke ＝h Duration of damping down /16+0.5 (2), n Empty coke , the number of the empty coke in the blowing-down material, and rounding to get an integer, h Duration of damping down , the number of hours from the start of the blowing-down to the resumption of the blowing-down, h, adding the empty coke after 12 batches of the blowing-down material are added, and after 6-8 hours, blowing-down, wherein the first batch of the empty coke is positioned at the upper part of the belly, calculating the number of the empty coke according to the formula (2), adding one empty coke every 3 batches of ores, and the distribution angle of the empty coke is consistent with the distribution angle of the middle coke of a normal material; Fourthly, maintaining 15-20 kg/tFe of the proportional coke butyl in the damping down material; After hollow coke is added into the damping down material, the furnace top distribution matrix should be correspondingly adjusted when the damping down material is loaded due to large change of ore coke ratio, a blast furnace with a central coke adding mode is adopted, the number of circles of centers Jiao Juanshu 0.2.2-0.3 is reduced, the proportion of the central coke is reduced by 1.0% -2.0%, the total weight of the central coke is kept consistent with that of normal production before damping down, and the weight is 3.5-6.5 t until damping down; and step six, rapidly adding air in the initial stage of air supply recovery.
2. The method for improving the blast furnace damping down material loading process and the initial gas utilization rate of air supply according to claim 1, wherein the air supply is quickly added in the initial stage of air supply recovery in the step six, so that the air supply ratio reaches 0.55-0.65, namely the air quantity/furnace volume reaches 0.55-0.65.

Description

Method for improving blast furnace damping down material loading process and initial gas utilization rate of air supply Technical Field The invention relates to a blast furnace ironmaking technology, in particular to a method for improving the blast furnace damping down material loading process and the gas utilization rate in the initial stage of air supply. Background The blast furnace is subjected to planned production stopping and damping down maintenance equipment after continuously running for a plurality of months. The furnace has no coke, coal dust burning and heat brought by hot air during the period of blowing down and stopping production, and the temperature in the furnace is gradually reduced, so that the blast furnace can improve the heat of slag iron by various measures before planned blowing down, namely during the blowing down material loading process and the initial stage of blowing-in recovery, so as to ensure that the slag iron has enough temperature to flow, and the main measures are to increase the fuel consumption, in particular the coke consumption. As the coke dosage increases, the coke ratio in the furnace gradually decreases, the gas permeability of the material column becomes better, so that the coal gas is easier to directly reach the furnace top through the coke layer to reduce the opportunity of contacting and reacting with the ore, and the CO in the coal gas cannot be fully converted into CO 2, namely the utilization rate of the coal gas is reduced. With the reduction of the gas utilization rate, iron oxide in the ore cannot be fully reduced by CO, and carbon must be consumed for direct reduction after entering a hearth, so that the fuel consumption is increased, and the hearth heat is reduced. The utilization rate of the blast furnace gas in normal production operation is generally 48% -50%, the utilization rate of the gas is generally reduced by 4% -5% in the traditional blast furnace damping down material loading process and the operation in the initial stage of air supply recovery, the utilization rate of the gas is reduced to 43% -45%, and the fuel ratio is increased by 20-30 kg/t. Through process optimization adjustment, the gas utilization rate is improved in the process of loading the damping down material and in the initial stage of air supply recovery, so that the fuel consumption can be effectively reduced, the iron slag heat is improved, and the smooth running of the recovery of the furnace condition is promoted. The method aims to provide a method for improving the gas utilization rate of a blast furnace in the blowing-down material loading process and the initial air supply stage, and aims to solve the problem that the gas utilization rate is greatly reduced due to the increase of the coke consumption in the blowing-down material loading process and the initial air supply stage before long-term blowing-down of the blast furnace, and the gas utilization rate is improved from 44% to over 46% by adjusting parameters such as the arrangement mode of the blowing-down material, a furnace top distribution matrix, the air supply speed during air supply recovery and the like, so that the fuel consumption is reduced by 10-15 kg/tFe, and the smooth recovery of the furnace condition is ensured. Disclosure of Invention The invention aims to solve the problems and provide a method for improving the gas utilization rate in the blast furnace damping down material loading process and the initial air supply stage. The method for improving the coal gas utilization rate in the blast furnace damping down material loading process and the air supply initial stage comprises the following steps that firstly, the weight of ore batches is maintained unchanged in two smelting periods before the blast furnace damping down, 10kg/t is increased on the basis of normal production coke ratio in a coke charge increasing mode, and the normal coke ratio is determined according to the actual condition of the blast furnace operation and ranges from 320 kg/t to 360kg/t; determining a basic coke ratio of a damping down material according to the damping down time by using a formula (1), wherein the basic coke ratio of the damping down material is K Damping material ＝K Normal material ＋h When the user is on a break multiplied by 1.0 (1), the basic coke ratio of the damping down material is K Damping material , the coke ratio of the damping down material is kg/t, the coke ratio of the damping down material is K Normal material , the coke ratio of the damping down material is kg/t, the number of hours from the start of the damping down to the re-blowing is h, the damping down time is increased by 1h, the damping down material with the damping down material ratio of K Damping material is increased by 1.0kg/t, the weight of the damping down material is consistent with the weight of the ore batch in normal production, the weight of the ore batch in normal production is 40-180 t, the third step is that the