阅读说明：本技术 一种转炉炉底修补方法 (Converter bottom repairing method ) 是由 邓长付 林伟忠 赵科 马欢 刘志明 *** 覃小峰 谢杰智 于 2019-05-29 设计创作，主要内容包括：本发明涉及一种转炉炼钢的技术领域,更具体地说,它涉及一种转炉炉底修补方法,其技术方案要点是：转炉出钢结束后,翻空熔渣；将补炉料翻入炉内；摇炉；调节转炉底吹参数；加入冶金焦炭；静置烧结；加入石灰覆盖。本发明通过加入额外助燃升温材料并快速燃烧升温,进而提高补炉料烧结温度,提高补炉效果,并缩短转炉炉底修补时间,使炉底与炉衬其它部位侵蚀速度相当,避免漏钢事故,实现炉衬长寿化。(The invention relates to the technical field of converter steelmaking, in particular to a converter bottom repairing method, which has the technical scheme key points that: after tapping of the converter is finished, emptying the slag; turning the repairing mass into the furnace; shaking the furnace; adjusting bottom blowing parameters of the converter; adding metallurgical coke; standing and sintering; and adding lime for covering. The invention adds extra combustion-supporting temperature-raising material and rapidly burns and raises temperature, thereby improving the sintering temperature of the fettling material, improving the fettling effect, shortening the repairing time of the converter bottom, ensuring that the erosion speed of the converter bottom is equal to that of other parts of the furnace lining, avoiding steel leakage accidents and realizing the long service life of the furnace lining.)

1. The method for repairing the converter bottom is characterized by comprising the following steps of:

(1) after the converter tapping is finished and slag splashing is finished, emptying slag in the converter;

(2) turning the repairing mass into the furnace through a waste steel groove, wherein the quantity of the repairing mass is 10-20 kg/t steel;

(3) after the repairing mass is turned into the converter, swinging the converter which is vertically arranged by taking the swing angle as front and back 30 degrees, and paving the repairing mass to the position needing repairing;

(4) the bottom blowing parameters of the converter are adjusted as follows: after the repairing mass enters the furnace for 5 minutes, oxygen lance oxygen blowing and sintering are adopted, wherein the oxygen flow is 2600 m/h, the oxygen pressure is 0.1MPa and the gun position is 3.3 m;

(5) blowing oxygen for 3min, adding 260-310 kg of metallurgical coke, blowing oxygen for 3min, continuously adding 260-310 kg of metallurgical coke, and then blowing oxygen for 3 min;

(6) lifting the oxygen lance and standing and sintering for 15 to 20 minutes;

(7) and 2 tons of lime is added to cover the repairing mass before the repairing is finished.

2. The method for repairing a converter bottom according to claim 1, wherein: the parameters of the repairing mass are as follows: MgO is more than or equal to 72 percent; c is less than or equal to 5.2 percent; carrying out bulk density cultivation on the seeds at a rate of more than or equal to 2.0 g/cm; the apparent porosity is less than or equal to 40 percent; the compressive strength is more than or equal to 4 MPa.

Technical Field

The invention relates to the technical field of converter steelmaking, in particular to a converter bottom repairing method.

Background

The supply side of the steel industry is reformed, so that the proportion of low-carbon and low-phosphorus steel products smelted by a converter is increased; the converter low-molten iron ratio smelting is the requirement of energy conservation, consumption reduction and cost reduction in the steel industry, and the phenomenon of insufficient smelting heat source is caused. The high-temperature and high-oxidizability molten steel at the end point of the converter has double influences on stirring, scouring and erosion of the molten steel on the furnace lining, so that the erosion rate of refractory materials at the bottom of the converter is higher than that of other parts of the furnace lining, and the risk of steel leakage at the bottom of the converter is higher. The following modes are commonly used for maintaining the converter bottom at present:

the first is the traditional pouring and fettling process: the method is characterized in that after slag in the furnace is emptied, the repairing mass is turned into the furnace through a scrap steel groove, the furnace is shaken to the position to be repaired, and the repairing mass is naturally sintered by means of the residual temperature of the furnace lining, so that the process cannot provide an additional heat source for the repairing mass, the sintering temperature is low, the sintering time is long, the sintering time of the repairing mass is as long as more than 45 minutes, the sintering quality is poor, and the problem of material collapse is easy to occur.

The second is a process for repairing the bottom of the furnace by remaining thick slag: and (3) completely discharging molten steel in the furnace during tapping, only leaving half of slag for slag splashing, shaking the furnace front and back to hang slag, and shaking the furnace to maintain the furnace bottom by utilizing high-melting-point substances precipitated after the slag is condensed. Because the time for condensing and separating out high-melting-point substances from the slag is long, the time for replenishing the furnace bottom by remaining the thick slag is usually longer than 3 hours, the MgO of the final slag of the converter is generally 8-12%, the melting point of the final slag is lower, the slag is not resistant to corrosion, and the furnace replenishing effect is poor.

The third is that Chinese patent with publication number CN107012289A discloses a method for repairing the bottom of a converter, which comprises the following main process steps: after steel is discharged from the furnace, more than 45Kg/t of slag is left in the furnace, after the fettling material with the quantity of 4.8Kg/t to 5.2 Kg/t of steel is directly added, slag is splashed for 3 minutes from high to low according to the position of a slag splashing gun, and the slag is left and stands for more than 30 minutes. The disadvantages of this process are: firstly, as the repairing mass is diluted by the slag, the MgO content in the repairing mass is about 18 percent and is lower than 70 percent of the MgO content of a furnace lining brick, thus influencing the erosion resistance of the furnace repairing mass; and secondly, in the fettling process, the fettling material is sintered by utilizing the residual heat of the furnace slag, the sintering temperature is low, and the sintering effect is poor.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a method for repairing the bottom of a converter, which improves the sintering temperature of repairing materials and the repairing effect by adding additional combustion-supporting heating materials and quickly burning and heating, shortens the repairing time of the bottom of the converter, ensures that the corrosion speed of the bottom of the converter is equal to that of other parts of a furnace lining, avoids steel leakage accidents and realizes the long service life of the furnace lining.

The technical purpose of the invention is realized by the following technical scheme: a converter bottom repairing method comprises the following steps:

(1) after the converter tapping is finished and slag splashing is finished, emptying slag in the converter;

(2) the repairing mass is turned into the furnace through the scrap steel groove, and the quantity of the repairing mass is 10-20 kg/t steel;

(3) after the repairing mass is turned into the converter, swinging the converter which is vertically arranged by taking the swing angle as front and back 30 degrees, and paving the repairing mass to the position needing repairing;

(4) the bottom blowing parameters of the converter are adjusted as follows: after the repairing mass enters the furnace for 5 minutes, oxygen lance oxygen blowing and sintering are adopted, wherein the oxygen flow is 2600 m/h, the oxygen pressure is 0.1MPa and the gun position is 3.3 m;

(5) blowing oxygen for 3min, adding 260-310 kg of metallurgical coke, blowing oxygen for 3min, continuously adding 260-310 kg of metallurgical coke, and then blowing oxygen for 3 min;

(6) lifting the oxygen lance and standing and sintering for 15 to 20 minutes;

(7) and 2 tons of lime is added to cover the repairing mass before the repairing is finished.

The invention is further configured to: the parameters of the repairing mass are as follows: MgO is more than or equal to 72 percent; c is less than or equal to 5.2 percent; carrying out bulk density cultivation on the seeds at a rate of more than or equal to 2.0 g/cm; the apparent porosity is less than or equal to 40 percent; the compressive strength is more than or equal to 4 MPa.

In conclusion, the invention has the following beneficial effects:

firstly, the problem of thermal compensation sintering on a fettling part when the fettling is fettled is effectively solved, fettling materials are firmly and quickly bonded on the fettling part of the furnace bottom, the fettling effect of the furnace bottom is obviously improved, and steel leakage accidents of the furnace bottom are avoided;

secondly, the erosion of the converter bottom is basically synchronous with other erosion, thereby realizing the consistency of the erosion speed of the converter lining and the long service life of the lining.

Detailed Description

The present invention will be described in detail with reference to examples.

The embodiment of the method for repairing the bottom of a converter is a 120-ton converter, and the main technical parameters of the repairing mass are as follows: MgO is more than or equal to 72 percent; c is less than or equal to 5.2 percent; carrying out bulk density cultivation on the seeds at a rate of more than or equal to 2.0 g/cm; the apparent porosity is less than or equal to 40 percent; the compressive strength is more than or equal to 4 MPa.