CN111944945A

CN111944945A - Direct tapping method for converter without turning up converter

Info

Publication number: CN111944945A
Application number: CN202010759804.5A
Authority: CN
Inventors: 王玉刚; 段永卿; 师艳秋; 赵广勋; 宋依新; 张进红; 樊赛
Original assignee: Handan Iron and Steel Group Co Ltd; HBIS Co Ltd Handan Branch
Current assignee: Handan Iron and Steel Group Co Ltd; HBIS Group Hansteel Co; HBIS Co Ltd Handan Branch
Priority date: 2020-07-31
Filing date: 2020-07-31
Publication date: 2020-11-17

Abstract

The invention relates to a direct tapping method without turning over a converter after a converter rises a lance, belonging to the technical field of metallurgy.A converter blowing end point oxygen lance is lifted to a waiting position automatically, an oxygen lance control mode is switched to realize manual control of the lance position, the head of the oxygen lance is inserted into a furnace opening for 1.0-1.5m through manual control, and the depth of the head of the oxygen lance entering the furnace opening is judged according to the difference between the absolute height of the oxygen lance and the absolute height of the furnace opening. And opening the nitrogen stop valve, opening the flow regulating valve to 100 percent, and continuously blowing nitrogen for 10-30 s. The damage of steel-making equipment caused by the slag overflowing from the steel tapping furnace mouth is avoided, and the quality accident that the molten steel quality is influenced by rephosphorization caused by the splashing of the steel slag into the steel ladle is also reduced.

Description

Direct tapping method for converter without turning up converter

Technical Field

The invention belongs to the technical field of metallurgy, and particularly relates to a converter lance-lifting direct tapping method without turning over a converter.

Background

The converter steelmaking of steel enterprises in China mainly adopts a constant-voltage variable lance operation mode, namely, the early slagging, the middle decarburization heating and the later intensified stirring are realized by controlling the oxygen supply lance position.

Aiming at the problems that the existing steel market situation is poor continuously, each large steel factory thinks about the best method to reduce the cost, some steel factories adopt a mode of eating more low-price iron-containing cold materials to reduce the steel-making cost of a converter, so that the converter operation is difficult, a large amount of iron-containing cold materials are added, the slag quantity of the converter is increased, the converter equipped with a sublance is difficult to start up to discharge steel, the converter with a large slag quantity in the converter directly discharges steel, a large amount of slag overflows from a furnace opening frequently, steel-making equipment is damaged, the slag splashes into a steel ladle to cause rephosphorization to influence the quality of molten steel, the composition of the molten steel exceeds the standard when the rephosphorization is serious, the large amount of slag overflowed out after the converter threatens the safety of workers behind the converter, and the labor intensity of the workers is greatly increased. In order to avoid the situations, an operator often adopts the operation of reversing the furnace and deslagging before tapping, and although a large amount of slag is prevented from overflowing from a furnace opening in the tapping process, the temperature in the furnace is lost in the reversing and deslagging process, the power consumption of the LF furnace is increased, and the production rhythm is influenced.

Disclosure of Invention

The invention aims to solve the technical problems that the converter has large end-point slag amount and a large amount of slag overflows from a converter mouth for direct converter reversing and steel tapping.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a converter lance lifting and direct steel tapping method without turning over is characterized in that after a converter blowing end point oxygen lance is lifted, a lance head is inserted into a furnace mouth for 1.0-1.5m, a nitrogen cut-off valve is opened, and nitrogen is continuously blown for 10-30 s.

The insertion depth of the oxygen lance is 1.0-1.5m below the furnace mouth. The slag pressing effect is achieved by blowing nitrogen, and tapping operation is performed after nitrogen blowing, so that direct tapping without turning over the furnace and deslagging is realized.

Preferably, the slag layer in the furnace is blown away by blowing nitrogen.

Preferably, the lance tip is inserted into the furnace mouth for 1.0-1.5m and is manually controlled.

Preferably, after the oxygen lance is lifted at the blowing end point of the converter, the oxygen lance is automatically lifted to a waiting position, and the control mode of the oxygen lance is switched to realize manual control of the lance position.

The control mode of the converter oxygen lance comprises automatic control and manual control, and after the converter blowing end point oxygen lance is lifted, the oxygen lance is automatically lifted to a waiting position, and the control mode of the oxygen lance is switched to the manual control mode.

Preferably, the depth of the oxygen lance head entering the furnace mouth is judged according to the difference value of the absolute height of the oxygen lance and the absolute height of the furnace mouth.

Preferably, the nitrogen flow rate is: the nitrogen flow regulating valve was opened to 100%.

Preferably, the nitrogen blowing time is determined according to the condition that the furnace slag is splashed out of the furnace mouth, and after the nitrogen blowing is started, if a large number of dense slag sheets appear at the furnace mouth, the nitrogen blowing time is controlled according to the upper limit of 30 s; if only a few slag sheets are splashed at the furnace mouth, the air blowing time is controlled according to the lower limit of 10 s.

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in: the invention relates to a direct steel tapping method without turning over a converter during converter lance lifting, which completely eradicates the damage of steel-making equipment caused by slag overflow at a steel tapping furnace mouth. The quality accident that rephosphorization affects the molten steel quality caused by splashing of the steel slag into the steel ladle is reduced, the amount of the steel slag in the steel ladle is obviously reduced, the alloy consumption is saved, impurities in the molten steel are reduced, and the molten steel quality is improved. The slag is not overflowed at the furnace mouth in the tapping process, the safety of workers behind the furnace is guaranteed, and the working environment is relatively improved. And the labor intensity of workers is reduced. And the converter is not turned over at the end point of the converter, so that the temperature loss is reduced, and the power consumption of the LF furnace is saved. Sixthly, the production rhythm is improved, and the slag pouring time is saved for 3-5min for each furnace. The advantages of the converter equipped with the sublance are fully exerted, the later-stage dynamic control is realized, and the direct steel tapping without turning over the converter after the sublance is started is realized.

Detailed Description

The invention relates to a method for directly tapping steel without turning over a converter after a converter is started, wherein after an oxygen lance is lifted at the blowing end point of the converter, the oxygen lance is automatically lifted to a waiting position, the control mode of the oxygen lance is switched, the lance position is manually controlled, the head of the oxygen lance is inserted into a furnace opening for 1.0-1.5m through manual control, and the depth of the head of the oxygen lance entering the furnace opening is judged according to the difference value of the absolute height of the oxygen lance and the absolute height of the furnace opening. And opening the nitrogen stop valve, opening the flow regulating valve to 100%, continuously blowing nitrogen for 10-30s, and blowing the slag layer in the furnace open. The time for blowing the nitrogen is determined according to the condition that the furnace slag is splashed out of the furnace mouth, and after the nitrogen is blown, if a large number of dense slag sheets appear at the furnace mouth, the time for blowing is controlled according to the upper limit of 30 s; if only a few slag sheets are splashed at the furnace mouth, the air blowing time is controlled according to the lower limit of 10 s.

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

Examples 1-6 production was carried out in the above-described manner, and the depth of insertion of the lance tip into the mouth, the number of slag pieces at the mouth after the start of nitrogen blowing, and the duration of nitrogen blowing were as shown in Table 1.

TABLE 1

In the examples 1-6, after the gun is started, the steel is directly tapped without turning over the furnace and deslagging, and the condition that the molten steel is rephosphorized due to the fact that slag overflows from a furnace mouth and slag splashes to a ladle does not occur in the tapping process.

Although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: modifications and equivalents may be made thereto without departing from the spirit and scope of the invention and it is intended to cover in the claims the invention as defined in the appended claims.

Claims

1. A converter lance lifting and direct steel tapping method without turning over is characterized in that after a converter blowing end point oxygen lance is lifted, a lance head is inserted into a furnace mouth for 1.0-1.5m, a nitrogen cut-off valve is opened, and nitrogen is continuously blown for 10-30 s.

2. The method for direct tapping without turning over a converter according to claim 1, wherein a slag layer in the converter is blown off by blowing nitrogen gas.

3. The method for direct tapping without turning over a converter according to claim 1, wherein the lance tip is inserted into the mouth for 1.0 to 1.5m by manual control.

4. The method for direct tapping of steel without turning over the converter after lance lifting in the converter blowing end point of claim 3, wherein the lance is automatically lifted to a waiting position after the lance lifting in the converter blowing end point, and the lance position is manually controlled by switching the lance control mode.

5. The method for direct tapping without turning over the converter during lance lifting according to claim 1, wherein the depth of the lance tip entering the converter mouth is determined according to the difference between the absolute height of the lance and the absolute height of the converter mouth.

6. The method for direct tapping without turning over a converter during converter lance lifting according to claim 1, wherein the nitrogen flow rate is controlled by: the nitrogen flow regulating valve was opened to 100%.

7. The method for directly tapping steel from a converter without turning over a converter as claimed in claim 1, wherein the time for blowing nitrogen is determined according to the condition that slag splashes from the converter mouth, and after the nitrogen is blown, if a large number of dense slag fragments appear at the converter mouth, the blowing time is controlled according to an upper limit of 30 s; if only a few slag sheets are splashed at the furnace mouth, the air blowing time is controlled according to the lower limit of 10 s.