CN-122012851-A - Method for prolonging service life of top-bottom combined blown converter refractory material

CN122012851ACN 122012851 ACN122012851 ACN 122012851ACN-122012851-A

Abstract

The invention discloses a method for prolonging the service life of a top-bottom combined blown converter, wherein the furnace bottom and the furnace body refractory are divided into N areas according to the number of bottom blowing elements, the three-dimensional erosion condition of the converter refractory is monitored, the process is controlled according to the erosion condition of each area, when the erosion depth of the furnace bottom refractory in a certain area of the converter is more than or equal to 350mm and the erosion depth of the furnace body refractory is less than 400mm, the ratio of bottom blowing natural gas in the area is up-regulated to 13-15%, when the carbon content in the later stage of the converter smelting is less than or equal to 0.06%, the oxygen blowing from a bottom gun is switched into bottom blowing argon, when the erosion depth of the furnace bottom refractory in a certain area of the converter is more than or equal to 350mm and the erosion depth of the furnace body refractory is more than or equal to 400mm, the bottom blowing oxygen flow in the area is down-regulated by 10-15%, and the bottom blowing oxygen flow in other areas is up-regulated by 10-15%. The invention can prolong the service life of a single furnace bottom to more than 1500 furnaces, lay a foundation for the accumulated service of 4 furnace bottoms, strengthen the control of furnace body refractory materials and slow down the erosion rate of the furnace body refractory materials.

Inventors

HAN JIAN
YAN LONGGE
GAO FUBIN
MENG FANLEI
JIA GUOXIANG
ZHANG TAO
ZHOU DAN
TANG XIAOYU

Assignees

邯郸钢铁集团有限责任公司
河钢股份有限公司邯郸分公司

Dates

Publication Date: 20260512
Application Date: 20260203

Claims (4)

1. A method for prolonging service life of top-bottom combined blown converter refractory is characterized in that the furnace bottom and the furnace body refractory are divided into N areas according to the number of bottom blowing elements, three-dimensional erosion conditions of the converter refractory are monitored, and the process is controlled as follows according to the erosion conditions of the areas: When the corrosion depth of the furnace bottom refractory material in a certain area of the converter is more than or equal to 350mm and the corrosion depth of the furnace body refractory material is less than 400mm, the proportion of bottom blowing natural gas in the area is up-regulated to 13-15%, and when the carbon content in the later stage of converter smelting is less than or equal to 0.06%, bottom blowing oxygen is switched into bottom blowing argon; When the corrosion depth of the furnace bottom refractory material in a certain area of the converter is more than or equal to 350mm and the corrosion depth of the furnace body refractory material is more than or equal to 400mm, the bottom oxygen blowing flow in the area is adjusted downwards by 10-15%, and the bottom oxygen blowing flow in other areas is adjusted upwards by 10-15%; When the corrosion depth of the refractory material at the bottom of a certain area of the converter is more than or equal to 500mm, bottom blowing in the area is canceled, and the gas quantity of bottom blowing elements in other areas is increased by 15-20%.
2. The method for improving the service life of the top-bottom combined blown converter according to claim 1, wherein the zones are divided in such a way that central lines are drawn between adjacent rows and adjacent columns of bottom blowing elements, all the central lines extend to the boundary of the furnace bottom and divide the furnace bottom into N furnace bottom zones, separation lines are drawn vertically upwards from the intersection points of the central lines and the boundary of the furnace bottom and divide the furnace body into N furnace body zones, and the furnace bottom zones and the furnace body zones corresponding to the upper and lower parts are divided into one zone and the furnace interior refractory is divided into N zones.
3. The method for improving the refractory life of the top-bottom combined blown converter, as set forth in claim 1, is characterized in that the converter has a 1000-furnace bottom life less than or equal to 1500 furnaces, lime powder is blown in the later stage of smelting, the flow is controlled to be 400-600 kg/min, and the total blowing amount is 1.0-1.5 t/furnace; The service life of the bottom of the converter is more than 1500, the flow of bottom blowing lime powder in the later smelting stage is maintained at 400-600 kg/min, and the total blowing amount is 1.5-2.5 t/furnace.
4. A method for improving the life of refractory materials of a top-bottom combined blown converter according to claim 1,2 or 3, wherein when the average value of the heights of refractory materials at the gun positions at the bottom of the converter bottom is less than or equal to 500mm, the converter bottom is replaced, the masonry height h i+1 of the replaced converter bottom satisfies the following formula (1), (1) Wherein w is the converter loading, kg, ρ is the molten steel density, H i+1 is the designed height of the refractory at the (i+1) th furnace bottom of the converter, H 1 is the designed height of the refractory at the (1) st furnace bottom, mm, R 1 is the radius at the (H 1 ) position of the furnace height, mm, R i+1 is the average radius of the furnace at the (H i+1 ) position of the (i+1) th furnace bottom refractory, R 1 is the average radius of the furnace at the (H) position of the (1) st furnace bottom, R i+1 is the average radius of the furnace at the (i+1) th furnace bottom, mm, wherein H is calculated by the following formula (2), (2)。

Description

Method for prolonging service life of top-bottom combined blown converter refractory material Technical Field The invention relates to the technical field of converter smelting, in particular to a method for prolonging the service life of a top-bottom combined blown converter refractory. Background The top-bottom combined blowing converter (KOBM converter) is used for realizing top-bottom combined blowing by blowing oxygen at the top and blowing gas (such as oxygen, argon or nitrogen) at the bottom simultaneously and spraying powder. ‌ is to realize the high-efficiency smelting targets of uniform temperature and rapid reaction of a large converter molten pool, the industry generally adopts a mode of enhancing the strength of bottom blowing to improve the metallurgical dynamic conditions of the molten pool, and the bottom blowing gas comprises oxygen, nitrogen, argon and the like. The bottom blowing amount of the conventional converter is controlled below 0.15Nm 3/(min.t), and the bottom blowing amount of the KOBM converter can reach 0.55-1.0 Nm 3/(min.t), which is about 10 times of that of the conventional converter. Although the smelting efficiency can be remarkably improved, the problem of serious refractory erosion is caused, and the service life of the converter refractory, particularly the converter bottom refractory, is seriously insufficient. In the prior art, the average service life of a single furnace bottom of a KOBM converter is about 1200 furnaces, and the international common practice is matched with 3 furnace bottom replacement at most because the service life of furnace body refractory is insufficient, so that the whole service life of the converter is generally 4000-5000 furnaces and is far lower than 6000-8000 furnaces of a conventional converter. The cost of the converter refractory is obviously increased, and the popularization and the application of the strong bottom blowing smelting process are severely restricted. The core contradiction of the problem is that under the strong bottom blowing working condition, strong flow of molten steel and high-temperature oxidation environment form severe scouring and chemical erosion on furnace bottom refractory, partial erosion pits are easily caused by uneven bottom blowing flow distribution, the service life of the furnace bottom refractory is shortened, and the service life of the furnace bottom refractory is shortened due to poor synergism of the furnace bottom and the furnace bottom refractory, namely abnormal flow field of a molten pool is caused by the partial erosion of the furnace bottom, the corrosion of the furnace bottom partial refractory is aggravated, and the service life of the furnace bottom refractory is shortened. In the prior art, the control of the furnace body refractory materials is lacking, the new furnace bottom design is not optimized according to the corrosion state of the furnace body, so that the furnace body refractory materials are severely corroded after 3 furnace bottoms are in service, the 4 th furnace bottom can not be supported for replacement, the converter can only be stopped for maintenance, and the service life of the converter is limited. In the prior art, the service life of refractory materials is prolonged by single means of improving the MgO content in slag, strengthening slag splashing protection, and the like, but the methods cannot solve the problems that the refractory materials of a furnace body are rapidly lost under the strong bottom blowing working condition, a furnace bottom partition bottom blowing control method based on the erosion condition of the refractory materials is not established, the matching mechanism of the building height of the furnace bottom and the erosion condition of the refractory materials of the furnace body cannot break through 'local strong erosion + the non-cooperation of the service life of the furnace body', and the maximum matching of 3 furnace bottoms is caused. The industry faces the technical bottleneck that the high-efficiency smelting with strong bottom blowing and the long-service-life operation of the converter cannot be considered for a long time. Therefore, a comprehensive scheme for improving the service life of a single furnace bottom, cooperatively controlling furnace body-furnace bottom refractory and accurately matching the furnace bottom and the furnace body is needed. Disclosure of Invention The invention aims to provide a method for improving the service life of a top-bottom combined blown converter by cooperatively controlling a furnace body and a furnace bottom refractory. In order to solve the technical problems, the invention adopts the technical scheme that the furnace bottom and furnace body refractory are divided into N areas according to the number of bottom blowing elements, the three-dimensional erosion condition of the converter refractory is monitored, and the process is controlled as follows according to the erosion condition of each ar