CN-122012826-A - Method for quickly recovering short-term damping-down furnace condition of blast furnace

Abstract

The invention relates to the field of iron making of a ferrous metallurgy blast furnace, in particular to a method for quickly recovering a short-term damping-down furnace condition of the blast furnace. The short-term damping-down (less than or equal to 4 hours) furnace condition quick recovery technology of the blast furnace is mainly technically characterized by comprising the steps of 1) adding Jiao Bure of decoking load, improving the coke ratio by 10-15kg/t, adding 2-3t of coke (or adding coke charge% -30% of coke) for supplementing heat each time 3-4 hours and 1-2 hours earlier than the damping-down time, and 2) damping down by a normal stockline, wherein the stockline is not more than 2.0m. 3) And (3) during air supply, the ore batch is removed to 80% -85% of the normal ore batch, the coke ratio is maintained to 355-365kg/t, the material is discharged after the material is moved, the air is added to 1500-1800m 3 /min (40% -50% of the normal air quantity), coal injection and oxygen enrichment are started, the air quantity is recovered to be normal for 1-2 h, and the oxygen enrichment is normal for 2-4 h. 4) And the accumulated air quantity reaches 15-20 ten thousand m 3 after air supply to obtain the first furnace iron.

Inventors

• TANG SHUNBING
• LIU LANPENG
• ZHAO XUEBIN
• ZHANG ZHI
• SONG JIANZHONG
• GONG LIWEI
• WANG ZHAOHUI
• QIAO SHI
• HE MINGZHENG
• WU SHUYONG

Assignees

• 山西太钢不锈钢股份有限公司

Dates

Publication Date

20260512

Application Date

20260205

Claims (1)

1. 1. A method for quickly recovering short-term damping-down furnace conditions of a blast furnace is characterized by comprising the following steps: (1) Adding Jiao Bure to 1) maintaining ore batches when the furnace condition is stable, adding coke charge to 400kg of decoking load, increasing the coke ratio to 10 to 15kg/t, increasing the coke ratio to 355 to 365kg/t, controlling the coke ratio to not more than 170kg/t according to the coal ratio, heating to 0.5 to 0.6, reducing the slag alkalinity to 1.15 to 1.20, 2) adding 2 to 3t coke or coke charge to 30 percent of coke before blowing down for 3 to 5 hours and 1 to 2 hours respectively, adding 1 to 2t of silica to balance the slag alkalinity to 1.15 to 1.20, and adding 1 to 2t center coke or coke charge to 30 percent of coke in the process of reducing the blowing down; (2) The furnace temperature is raised to reduce the alkalinity, the slag alkalinity is regulated to be 0.02-0.04 in 6-8h before the blowing down, the furnace temperature is raised to be 0.55-0.60 in 2-4h before the blowing down, and the molten iron temperature is measured to be 1480-1520 ℃; (3) Adding coal injection, namely adding coal injection amount by 2-3t/h 1-2h before damping down; (4) The iron outlet and wind reduction arrangement comprises 1) keeping the iron outlet of a 2-furnace permeable before the wind break, calculating whether iron deficiency and slag discharge occur, and calculating that the deviation between the volume of the generated slag iron and the volume of the actual discharged slag iron is within 50m 3 according to the discharging theory of the furnace top, 2) opening the first iron outlet for 30-40 minutes after the wind break, and then opening the other iron outlet for iron simultaneously, 3) reducing wind, wherein the iron outlet is blown to a slag skimmer to start wind reduction, the wind break time is controlled to be 50-60 minutes, 4) observing the condition of the front end of the wind gap when water is seen in the wind reduction process, the front end of the wind gap is bright and active, no slag is gushed, and the wind filling is prevented; (5) A material line is used for damping down when damping down, and the material line is no more than 2.0m; (6) Cleaning the tuyere 1) if a tuyere with slag is found in the blowing-down process, organizing the tuyere in front of the furnace, and 2) before air supply, poking out the blocking mud before replacing the tuyere in front of the furnace to see red coke; (7) The air supply is recovered, namely, the ore batch is returned to 80% -85% of the normal ore batch, namely 50t-52t, the coke ratio is maintained to 355-365kg/t, the material is discharged after the material is moved, the air is added to 1500-1800m 3 /min to start coal injection and oxygen enrichment, the air quantity is recovered to be normal, namely 3600-3800m 3 /min for 1-2 h, and the oxygen enrichment quantity is normal, namely 12000-16000m 3 /h for 2-4 h; (8) When the first furnace iron is discharged, the accumulated air quantity reaches 15-20 ten thousand m 3 after air supply, and the first furnace iron is discharged in front of the furnace.

Description

Method for quickly recovering short-term damping-down furnace condition of blast furnace Technical Field The invention relates to the field of iron making of a ferrous metallurgy blast furnace, in particular to a method for quickly recovering a short-term damping-down furnace condition of the blast furnace. Background The blast furnace smelting production unit is used as an important link with the specific cost and the energy consumption of 60-70% in the long process of the steel industry, and the economic index of the production technology needs to be continuously improved to reflect the economical efficiency. The blast furnace is produced for 24 hours at a continuous high temperature and high pressure, during which the fault of production and equipment is unavoidable, temporary short-term (less than or equal to 4 hours) damping down treatment is required, and the short-term damping down and the rapid recovery of the blowing-in furnace condition are important manifestations of the blast furnace production operation and manager level. After the blast furnace is in a short-term damping down, the air supply recovery difficulty is high, and the main reason is that after the blast furnace is in a damping down state, the slag iron heat quantity is poor (the temperature of molten iron is measured to 1400-1450 ℃), the flow is difficult, the cleaning workload in front of the furnace is high, the in-furnace ventilation recovery process is slow, the recovery time is generally more than 8 hours, and the yield and quality losses are huge. A technique for quickly recovering the condition of blast furnace for short-term damping-down (4 hr or less) is disclosed, which can realize the safe, stable and quick recovery of the condition of blast furnace for 4 hr and the recovery of coke load to normal level. The method aims at providing a rapid recovery technology for the blast furnace short-term damping-down (less than or equal to 4 hours) constant-temperature furnace condition, through the technology, the safety, stability and rapid recovery of the constant-temperature furnace condition can be realized, the air, oxygen and top pressure are recovered to the normal production level within 1-2 hours of air supply, and the coke load is recovered to the normal level within 4 hours. The method reduces the recovery loss of the furnace condition during short-term damping down, reduces the water-taking frequency of the furnace top, protects the furnace top and furnace body cooling equipment, realizes reasonable gas flow distribution in the furnace as soon as possible, and promotes the return of the blast furnace to a normal production track with safety, stability, economy and long service life. Disclosure of Invention The invention aims to solve the problems and provides a method for quickly recovering the short-term damping-down furnace condition of a blast furnace. The invention aims to realize the method for quickly recovering the short-term damping-down furnace condition of a blast furnace, which comprises the following steps of (1) maintaining a mine batch when the furnace condition is stable, adding coke charge-400 kg of a decoking load to improve the coke ratio by 10-15kg/t, improving the coke ratio to 355-365kg/t, controlling the coke ratio to not more than 170kg/t according to the coal ratio, heating to the silicon content of 0.5-0.6, reducing the slag alkalinity by 1.15-1.20, 2) adding 2-3t coke or coke charge-30% of coke before damping-down for 3-5h and 1-2h respectively, adding silica to balance the slag alkalinity to 1.15-1.20, and adding 1-2t center coke or coke charge-30% of coke in the damping-down process; the method comprises (2) regulating slag alkalinity 0.02-0.04 down 6-8h before blowing down, (3) increasing coal injection amount 2-3t/h 1-2h before blowing down, (4) ventilation and reducing arrangement 1) keeping iron mouth of 2 furnaces before blowing down, calculating whether iron deficiency and slag discharge conditions are met, according to the theoretical iron content volume of slag generated by furnace top blanking calculation and the actual iron content of slag discharged are within 50m 3, (2) opening the first iron mouth for 30-40 min during blowing down, then opening the other iron mouth for iron discharge simultaneously, 3) reducing air, blowing the iron mouth to the slag skimmer to start reducing air, controlling the blowing down time to be 50-60 min, 4) observing the front end condition of the air mouth in the air reducing process, the front end of the tuyere is bright and active, no slag is gushed, the tuyere is prevented from being irrigated, (5) a normal stockline is used for blowing down when the tuyere is in a blowing down state, the stockline is not more than 2.0m, (6) the tuyere is cleaned, (1) the tuyere with slag gushed in the blowing down process is cleaned up before the tuyere is organized, 2) the blocking mud before the tuyere is replaced is poked to see red coke before the tuyere is blown