阅读说明：本技术 一种转炉浪涌式溅渣护炉法 (Surging slag splashing furnace protection method for converter ) 是由 *** 王兴 李成龙 许维康 周明 代平 郭传奇 于刚 高波 朱鹏 于 2019-10-17 设计创作，主要内容包括：一种转炉浪涌式溅渣护炉方法,包括如下步骤：(1)在执行完成传统的转炉溅渣护炉操作后,将顶吹氧枪高度调整至相对于炉底液位1.5米处；(2)氧枪定位后,重复进行开关高压氮气的操作；(3)操作完成后,就可以进行转炉倒渣作业或直接开始下一周期的冶炼。本发明的一种转炉浪涌式溅渣护炉方法,解决了转炉冶炼生产中所遇到的转炉熔池炉衬出现侵蚀不均衡的问题。该法具有成本低,操作简单,效果显著的特点。(A converter surging slag splashing protection method comprises the following steps: (1) after the traditional converter slag splashing protection operation is finished, the height of the top-blown oxygen lance is adjusted to be 1.5 meters relative to the liquid level of the bottom of the converter; (2) after the oxygen lance is positioned, the operation of switching on and off the high-pressure nitrogen is repeated; (3) after the operation is finished, the converter slag dumping operation can be carried out or the smelting of the next period can be directly started. The surging slag splashing furnace protection method for the converter solves the problem of unbalanced erosion of the converter molten pool furnace lining in the smelting production of the converter. The method has the characteristics of low cost, simple operation and remarkable effect.)

1. A converter surging slag splashing protection method is characterized by comprising the following steps:

(1) after the traditional converter slag splashing protection operation is finished, the height of the top-blown oxygen lance is adjusted to be 1.5 meters relative to the liquid level of the bottom of the converter;

(2) after the oxygen lance is positioned, the operation of switching on and off the high-pressure nitrogen is repeated;

(3) after the operation is finished, the converter slag dumping operation can be carried out or the smelting of the next period can be directly started.

2. The surge type slag splashing protection method for the converter according to claim 1, wherein the slag adjusting process for the converter splashing protection operation in the step (1) is a direct slag splashing process or a slag adjusting process after steel tapping.

3. The surge type slag splashing protection method for the converter according to claim 1, wherein the high-pressure nitrogen gas in the step (2) is repeatedly operated for 5-7 times, and the time for each switching is 4-6 seconds.

4. The surge type slag splashing furnace protection method for the converter according to claim 1 or 3, wherein when the high-pressure nitrogen is repeatedly top-blown, the instantaneous nitrogen blowing pressure is 1.25-1.4 MPa, and the flow rate is 65000-75000 Nm³/h。

5. The method for protecting a converter by surging slag splashing of the converter as claimed in claim 1, wherein the selection of the converter deslagging operation in the step (3) or the direct start of the smelting in the next period is based on the raw material conditions of the next molten steel and the composition requirements of the finished product.

Technical Field

The invention belongs to the technical field of maintenance processes of converter conditions of converter steelmaking, and particularly relates to a surging type slag splashing converter protection method for a converter.

Background

The maintenance of the converter lining is a great problem in the steel-making industry, and particularly the maintenance of the converter molten bath lining is difficult. Converter smelting is a series of physical and chemical reaction processes under high temperature conditions, and in the process, a furnace lining of a molten pool is corroded by a series of strong mechanical, physical and chemical actions. The main mechanism is as follows: 1) mechanical shock erosion. The operations of adding scrap steel, adding molten iron and the like are directly opposite to a large-surface furnace lining of a converter molten pool, and strong impact, abrasion and scouring are generated on the large-surface furnace lining, and are main factors of the corrosion of refractory materials of the furnace lining of the molten pool. 2) And (4) physical action. And in the smelting process, the molten steel and the furnace slag in the furnace melt and scour the furnace lining of the molten pool, and in the smelting process, the high-temperature reaction melts and damages the furnace lining of the molten pool. 3) Chemical action. The working layer of the converter lining is generally built by magnesia carbon bricks, and the magnesia carbon bricks contain a certain amount of graphite carbon which has poor wettability with slag and can block the penetration of the slag into the brick body; the thermal conductivity is good, the thermal shock resistance of the lining brick can be greatly improved, and the service life of the magnesia carbon brick lining is longer. However, the converter is in a strong oxidizing atmosphere, and high-temperature oxidizing gas can oxidize and remove part of carbon in the brick in the smelting process, so that the brick body structure is loosened and embrittled and is lost and damaged under fluid scouring.

The current converter steelmaking furnace condition maintenance process mainly adopts a mode of combining slag splashing furnace protection, gunning and fettling repair to maintain the converter lining. However, the current maintenance process for the converter steelmaking conditions is not suitable for maintaining the lining of the converter molten bath for two reasons. Firstly, the slag splashing furnace protection process is influenced by the factors of slag components, slag viscosity, oxygen lance position, nitrogen flow and slag splashing time, so that the slag is difficult to be uniformly and effectively splashed and adhered to the surface of a furnace lining of a molten pool. Secondly, gunning and fettling repair furnace maintains the furnace linings of the molten pool at the steel tapping side, the slag pouring side and the furnace bottom through fettling or raw dolomite, and the molten pool part at the trunnion side can only maintain the molten pool through gunning. The wet spray repair and the semi-dry spray repair commonly used for a molten pool can only maintain 3-furnace smelting generally, and the effect of maintaining a furnace lining is poor in continuity. In addition, the maintenance of the furnace lining is restricted by the production rhythm, so that effective and repeated spray repair cannot be guaranteed in the actual production. In conclusion, in the actual smelting production of the converter, the problem of unbalanced erosion of the converter molten pool furnace lining occurs, the service life of the converter furnace lining is greatly shortened, and the hidden danger of production halt caused by local over-fast erosion of the converter molten pool furnace lining is buried. Therefore, the current maintenance process of the converter steelmaking furnace condition is not suitable for maintaining the converter molten bath lining.

Disclosure of Invention

The invention aims to provide a surging slag splashing furnace protection method for a converter, which solves the problem of unbalanced erosion of a converter molten pool furnace lining in the smelting production of the converter. The method has the characteristics of low cost, simple operation and remarkable effect.

In order to achieve the purpose, the invention adopts the following technical scheme:

a converter surging slag splashing protection method comprises the following steps:

(1) after the traditional converter slag splashing protection operation is finished, the height of the top-blown oxygen lance is adjusted to be 1.5 meters relative to the liquid level of the bottom of the converter;

(2) after the oxygen lance is positioned, the operation of switching on and off the high-pressure nitrogen is repeated;

(3) after the operation is finished, the converter slag dumping operation can be carried out or the smelting of the next period can be directly started.

Further, the slag adjusting process for the converter splashing and protecting operation in the step (1) is a direct splashing process or a slag adjusting process after tapping steel.

Furthermore, the repeated operation times of the high-pressure nitrogen in the step (2) are 5-7 times, and the time for switching on and off each time is 4-6 seconds.

Further, when the high-pressure nitrogen is repeatedly top-blown, the instantaneous nitrogen-blowing pressure is 1.25 to 1.4MPa, and the flow rate is 65000 to 75000Nm³/h。

Further, the slag removal operation of the converter in the step (3) or the smelting selection of the next period is directly started according to the raw material conditions of the next molten steel and the component requirements of the finished product.

The invention has the following beneficial effects: the surge type slag splashing furnace protection method for the converter is simple to operate (1). The method is characterized in that after the traditional slag splashing process, the operation of repeatedly switching on and off the nitrogen switch with certain flow and certain gun position is added.

(2) The cost is low. The nitrogen used in the process is a byproduct of the oxygen production process. Compared with the traditional slag splashing furnace protection method, the operation only consumes 540-630 Nm in volume³Of nitrogen (c).

(3) The effect is obvious. The method effectively protects the furnace lining of the molten pool, slows down the erosion rate of the furnace lining, and the erosion rate of the molten pool is generally more than 0.1 mm/furnace before the method is used, but the erosion rate of the molten pool can be reduced to 0.085 mm/furnace or below after the furnace is protected by the method, so that the method solves the problem of unbalanced erosion of the furnace lining of the molten pool of the converter, prolongs the service life of the furnace lining of the converter to the maximum extent, and avoids the production stop accident caused by over-quick local erosion of the furnace lining of the molten pool of the converter.

Detailed Description

A converter surging slag splashing protection method comprises the following steps:

(1) after the traditional converter slag splashing protection operation is finished, the height of the top-blown oxygen lance is adjusted to be 1.5 meters relative to the liquid level of the bottom of the converter;

(2) after the oxygen lance is positioned, the operation of switching on and off the high-pressure nitrogen is repeated;

(3) after the operation is finished, the converter slag dumping operation can be carried out or the smelting of the next period can be directly started.

Further, the slag adjusting process for the converter splashing and protecting operation in the step (1) is a direct splashing process or a slag adjusting process after tapping steel.

Furthermore, the repeated operation times of the high-pressure nitrogen in the step (2) are 5-7 times, and the time for switching on and off each time is 4-6 seconds.

Further, when the high-pressure nitrogen is repeatedly top-blown, the instantaneous nitrogen-blowing pressure is 1.25 to 1.4MPa, and the flow rate is 65000 to 75000Nm³/h。

Further, the slag removal operation of the converter in the step (3) or the smelting selection of the next period is directly started according to the raw material conditions of the next molten steel and the component requirements of the finished product.