CN113699302A - Secondary lance discharging control method for accident lance lifting in converter smelting process - Google Patents
Secondary lance discharging control method for accident lance lifting in converter smelting process Download PDFInfo
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- CN113699302A CN113699302A CN202110887176.3A CN202110887176A CN113699302A CN 113699302 A CN113699302 A CN 113699302A CN 202110887176 A CN202110887176 A CN 202110887176A CN 113699302 A CN113699302 A CN 113699302A
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- lance
- oxygen
- accident
- converter smelting
- smelting process
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/28—Manufacture of steel in the converter
- C21C5/30—Regulating or controlling the blowing
- C21C5/35—Blowing from above and through the bath
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- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
A converter smelting process accident lance lifting secondary lance discharging control method is characterized in that after the converter smelting process accident lance lifting, an oxygen lance descends into a converter to blow nitrogen for 10-30 s, then oxygen blowing is carried out, and ferrosilicon is added when the oxygen lance reaches an oxygen opening point in the oxygen blowing process; in the oxygen blowing process, when the pressure of the oxygen lance reaches the set pressure, dolomite is added through the slag bin. The invention avoids metal loss caused by the slag pouring when the gun is started up in an accident, reduces the accident rate, is safe and reliable, has simple operation and ensures the normal and smooth operation of steel-making production.
Description
Technical Field
The invention belongs to the technical field of ferrous metallurgy, and particularly relates to a secondary lance discharging control method for an accident lance lifting in a converter smelting process.
Background
In the top-bottom combined blown converter steelmaking process, because equipment faults such as oxygen lance system, gasification cooling system, dust pelletizing system cause converter smelting process accident to carry the rifle to be a problem that sometimes takes place, such as the oxygen lance cooling advances the return water unusual, the high-voltage electric field trouble, ID fan stops etc. and all can cause this accident to take place, causes then the secondary to go down the rifle to smelt and produces very serious splash problem, produces a series of harm thereupon: (1) secondary gun-off smelting is easy to cause explosion venting accidents and environmental pollution; (2) the heavy splashing can increase the labor workload of staff in front of the furnace, and the staff is easy to scald and burn, thereby endangering the personal safety; (3) equipment damage can be caused by serious splashing, such as burning out of a motor of a fire door at the back of a stokehole furnace, large water leakage of an oxygen lance, burning out of a slag dumping operation platform and the like; (4) the severe splashing can cause the metal loss to increase and the consumption of steel materials to increase. The adverse factors seriously affect the smooth production of steelmaking, so an effective method must be adopted to inhibit the splashing problem generated by secondary lance feeding in the converter smelting process, and the method has very important practical significance.
At present, the conventional method is to pour slag after the gun is started in an accident, but the generation of splashing can not be avoided all the time when the gun is put down for the second time, and metal and heat loss are caused, so that time and labor are wasted, and the production rhythm of steelmaking is seriously influenced.
Disclosure of Invention
The invention aims to provide a method for controlling secondary lance discharge during accident lance lifting in the converter smelting process, which avoids splashing generated by secondary lance discharge in the converter smelting process.
The main reasons for severe splashing caused by secondary lance feeding of the converter are as follows: the secondary blow-on of the dry dedusting converter usually adopts a set explosion-proof mode, the oxygen ramp time is long, when the blowing oxygen pressure does not reach the set pressure, soft blowing is carried out for a long time after the converter is placed for a long time, the stirring capability of a molten pool is poor, the carbon-oxygen reaction is slow, a large amount of FeO in slag is generated, in addition, the content of the original FeO in the slag in the converter and the large amount of FeO are accumulated, until the oxygen pressure reaches the set blowing pressure, the carbon-oxygen reaction is suddenly intensified, a large amount of CO gas is instantly generated and discharged from a converter mouth, and meanwhile, a certain amount of molten steel and molten slag are carried, so that serious splashing is formed.
The technical scheme of the invention is as follows: a secondary lance discharging control method for an accident lance lifting in the converter smelting process is characterized in that after the accident lance lifting in the converter smelting process, an oxygen lance is lowered into a furnace for nitrogen blowing for 10-30 s and then oxygen blowing is carried out.
Further, in the oxygen blowing process, when the oxygen lance reaches an oxygen opening point, adding ferrosilicon; in the oxygen blowing process, when the pressure of the oxygen lance reaches the set pressure, dolomite is added through the slag bin.
Further, the oxygen blowing is carried out, when the pressure of the oxygen lance reaches the set pressure, the lance position is increased by 0.05-0.2 m.
Furthermore, after the gun is lifted in a converter smelting accident, the bottom blowing gas flow of the converter is quickly improved.
Further, in the nitrogen blowing process, front rocking furnace and rear rocking furnace are carried out for 1-2 times respectively, the front rocking furnace is rocked to the large charging face by 40-60 degrees, and the rear rocking furnace is rocked to the small face steel tapping side by 20-40 degrees.
Furthermore, in the nitrogen blowing process of the oxygen lance, the lance head is inserted into the furnace mouth for 1-1.5 m, and the nitrogen pressure is 1.2-1.6 MPa.
Further, in the oxygen lance oxygen blowing process, the lance position is set to be 1.5-1.7 m, the oxygen pressure is set to be 0.6-0.7 MPa, and the flow rate is 400-500 Nm3/h。
Further, the adding amount of the ferrosilicon is 0.7-1.2 kg per ton of steel.
Furthermore, the addition amount of the dolomite is 2-3 kg per ton of steel.
And further, after the flame at the furnace mouth is normal, the normal converter bottom blowing flow and the oxygen lance position are recovered, and normal smelting is carried out.
In the nitrogen blowing process, the depth of the oxygen lance head inserted into 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.
The front rocking furnace laterally rocks 40-60 degrees towards the charging large surface, the rear rocking furnace laterally rocks 20-40 degrees towards the facet steel tapping, and the angle of inclination of 40-60 degrees relative to the vertical direction from the converter to the charging large surface is 40-60 degrees; the inclination angle of 20-40 degrees, namely the inclination angle of the converter to the facet tapping side relative to the vertical direction is 20-40 degrees.
The flame at the furnace mouth of the invention is normal, namely the flame is thick and powerful, is relatively soft, looks regular and stretches and contracts, the slag has no overflow trend, and microscopically shows that the carbon-oxygen reaction in a molten pool is carried out evenly, namely the smelting is carried out normally.
Adopt the produced beneficial effect of above-mentioned technical scheme to lie in:
the method for preventing splashing by lifting the lance and putting the lance twice in the converter smelting process has the main reason that the secondary lance is put to cause excessive accumulation of FeO in slag and violent carbon-oxygen reaction. Therefore, the method is used as a trigger, the bottom blowing gas flow of the converter is increased after the gun is started in an accident, the gun is manually lowered to blow the slag surface by nitrogen, the furnace is shaken back and forth, the dynamic condition of the carbon-oxygen reaction is improved, bubbles on the surface of the slag are damaged, the carbon-oxygen reaction is promoted to be carried out, the content of FeO in the slag is reduced, the secondary gun-off oxygen blowing is equivalent to soft blowing, and in order to prevent the excessive accumulation of FeO in the slag caused by soft blowing, the generated FeO is reduced by adding ferrosilicon, so that the carbon-oxygen reaction is delayed, the gun is lifted and added with dolomite in order to improve the viscosity and the melting point of the slag, so that the carbon-oxygen uniform reaction is realized, and the splashing is further prevented.
Detailed Description
Embodiments of the present invention will be described below. The present invention is not limited to the following embodiments.
A method for preventing splashing by secondary lance discharge during converter smelting process in accident lance lifting comprises the following specific operation steps:
(1) after the converter smelting accident gun is lifted, the bottom blowing gas flow of the converter is rapidly improved to 400-500 Nm3H, and selecting the oxygen lance operation mode as manual;
(2) manually descending the oxygen lance into a descending furnace, inserting a lance head into a furnace mouth for 1-1.5 m, manually opening a nitrogen cut-off valve to blow nitrogen, wherein the nitrogen pressure is 1.2-1.6 MPa, the nitrogen blowing time is 10-30 s, and then lifting the lance to a waiting position;
(3) shaking the furnace 1-2 times in front and at back, shaking the furnace to the large surface of the charge by 40-60 degrees, shaking the steel from the small surface by 20-40 degrees, and then shaking the furnace body;
(4) selecting the operation mode of the oxygen lance as 'automatic', clicking 'start blowing' to carry out secondary lance discharging, setting the lance position to be 1.5-1.7 m, setting the oxygen pressure to be 0.6-0.7 MPa, and setting the flow to be 400-500 Nm3/h；
(5) And when the position of the oxygen lance reaches an oxygen opening point, adding ferrosilicon, wherein the adding amount of the ferrosilicon is 0.7-1.2 kg per ton of steel.
(6) When the pressure of the oxygen lance reaches the set pressure, the lance position is increased by 0.05-0.2 m, and dolomite is added through a slag bin, wherein the addition amount of the dolomite is 2-3 kg per ton of steel.
(7) And after the flame at the furnace mouth is normal, recovering the normal converter bottom blowing flow and the oxygen lance position, and smelting normally.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Examples 1 to 5
In the examples 1-5, the converter smelting process has accident gun lifting, and the reasons for the accident gun lifting are shown in Table 1. After the gun is lifted in an accident, the operation is carried out according to the embodiment, the flow is shown in a table 2 after the flow of bottom blowing nitrogen is improved, the depth of the gun head of the oxygen gun inserted into a furnace mouth in the nitrogen blowing process, the nitrogen pressure and the nitrogen blowing time are shown in a table 2, the oxygen gun is secondarily lowered to the oxygen blowing process, the gun position set value, the flow set value and the pressure set value are shown in a table 2, the furnace shaking times and the front furnace shaking angle are shown in a table 3, the silicon iron adding amount and the dolomite adding amount are shown in a table 3, and the gun lifting height is shown in a table 3 when the pressure of the oxygen gun reaches the set pressure in the oxygen blowing process.
TABLE 1
In Table 1, SWRCH35K and SWRCH8A are both Japanese Standard JIS G3507-1: 2010 steel grade designation. The HRB400EB and the HRB400EC are both steel grade marks in GB 1499.2-2007 Hot rolled ribbed steel for reinforced concrete, and the Q355B is a steel grade mark in GB/T1591-2018 Low-alloy high-strength structural Steel.
TABLE 2
TABLE 3
In the examples 1-5, after the above operations, the flame at the furnace mouth is normal, and then the normal converter bottom blowing flow and the oxygen lance position are recovered, so that the normal smelting is realized, and no splashing accident occurs.
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 (10)
1. A secondary lance discharging control method for an accident lance lifting in the converter smelting process is characterized in that after the accident lance lifting in the converter smelting process, an oxygen lance is lowered into a furnace for nitrogen blowing for 10-30 s and then oxygen blowing is carried out.
2. The secondary lance discharging control method for the accident lance lifting in the converter smelting process according to claim 1, characterized in that ferrosilicon is added when the oxygen lance reaches the oxygen opening point in the oxygen blowing process; in the oxygen blowing process, when the pressure of the oxygen lance reaches the set pressure, dolomite is added through the slag bin.
3. The method for controlling secondary lance dropping in the converter smelting process according to claim 2, wherein the lance position is increased by 0.05-0.2 m when the pressure of the oxygen lance reaches the set pressure by oxygen blowing.
4. The method for controlling secondary lance discharge in the converter smelting process by accident lance lifting according to claim 1, wherein the flow rate of the converter bottom blowing gas is rapidly increased after the converter smelting accident lance lifting.
5. The method for controlling secondary lance discharge in an accident lance lifting manner in the converter smelting process according to claim 1, wherein the nitrogen blowing process is performed for 1-2 times respectively in a front rocking furnace and a rear rocking furnace, the front rocking furnace is rocked to the large charging surface by 40-60 degrees, and the rear rocking furnace is rocked to the small surface steel discharging side by 20-40 degrees.
6. The secondary lance dropping control method for the accident lance lifting in the converter smelting process according to any one of claims 1 to 6, wherein in the nitrogen blowing process of the oxygen lance, the lance head is inserted into a furnace mouth for 1 to 1.5m, and the nitrogen pressure is 1.2 to 1.6 MPa.
7. The method for controlling secondary lance discharging of the emergency lance in the converter smelting process according to any one of claims 1 to 6, wherein in the oxygen lance oxygen blowing process, the lance position is set to be 1.5 to 1.7m, the oxygen pressure is set to be 0.6 to 0.7MPa, and the flow rate is 400 to 500Nm3/h。
8. The method for controlling secondary lance discharge in the converter smelting process according to claim 2, wherein the addition amount of the ferrosilicon is 0.7-1.2 kg per ton of steel.
9. The method for controlling secondary lance discharge in the converter smelting process according to claim 2, wherein the addition amount of dolomite is 2-3 kg/ton of steel.
10. The method for controlling secondary lance discharge in the converter smelting process according to claim 7, wherein the normal converter bottom blowing flow and the normal oxygen lance position are recovered after the flame at the converter mouth is normal, and normal smelting is performed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110887176.3A CN113699302A (en) | 2021-08-03 | 2021-08-03 | Secondary lance discharging control method for accident lance lifting in converter smelting process |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202110887176.3A CN113699302A (en) | 2021-08-03 | 2021-08-03 | Secondary lance discharging control method for accident lance lifting in converter smelting process |
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| CN113699302A true CN113699302A (en) | 2021-11-26 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202110887176.3A Withdrawn CN113699302A (en) | 2021-08-03 | 2021-08-03 | Secondary lance discharging control method for accident lance lifting in converter smelting process |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103074463A (en) * | 2013-01-04 | 2013-05-01 | 宣化钢铁集团有限责任公司 | Operation method of lifting lance in the midway of converter steelmaking under dry dedusting condition |
| CN110735014A (en) * | 2019-10-29 | 2020-01-31 | 攀钢集团西昌钢钒有限公司 | method for blowing steel in furnace to reduce explosion and deflagration rate and explosion venting rate by dry dedusting |
-
2021
- 2021-08-03 CN CN202110887176.3A patent/CN113699302A/en not_active Withdrawn
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103074463A (en) * | 2013-01-04 | 2013-05-01 | 宣化钢铁集团有限责任公司 | Operation method of lifting lance in the midway of converter steelmaking under dry dedusting condition |
| CN110735014A (en) * | 2019-10-29 | 2020-01-31 | 攀钢集团西昌钢钒有限公司 | method for blowing steel in furnace to reduce explosion and deflagration rate and explosion venting rate by dry dedusting |
Non-Patent Citations (1)
| Title |
|---|
| 于春强: "转炉中途提枪后干法除尘系统防泄爆方法", 《河北冶金》 * |
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Application publication date: 20211126 |