CN113106196A - Clean steel smelting system and method - Google Patents
Clean steel smelting system and method Download PDFInfo
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- CN113106196A CN113106196A CN202110525305.4A CN202110525305A CN113106196A CN 113106196 A CN113106196 A CN 113106196A CN 202110525305 A CN202110525305 A CN 202110525305A CN 113106196 A CN113106196 A CN 113106196A
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- steel
- slag
- refining
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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
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/0087—Treatment of slags covering the steel bath, e.g. for separating slag from the molten metal
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/14—Plants for continuous casting
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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
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/06—Deoxidising, e.g. killing
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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
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/10—Handling in a vacuum
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- Engineering & Computer Science (AREA)
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- Metallurgy (AREA)
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- Analytical Chemistry (AREA)
- Mechanical Engineering (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
The invention relates to a clean steel smelting system and a clean steel smelting method, which belong to the technical field of metallurgy and comprise a primary smelting furnace, a slag-steel separating device, a refining furnace and a continuous casting ladle which are sequentially arranged along the flowing direction of molten steel, wherein the slag-steel separating device is used for removing high-oxidability steel slag in the molten steel, and is not subjected to deoxidation alloying operation during primary smelting steel tapping, and is subjected to deoxidation-alloying operation during refining. According to the invention, the slag-steel separation device is arranged, so that the high-oxidability steel slag of the primary smelting furnace is prevented from entering a refining process, the possibility of pollution of the molten steel is reduced, and the alloy consumption for steel slag deoxidation is reduced; meanwhile, the alloying operation is carried out after the deoxidation in the refining furnace, thereby not only improving the alloy yield, but also inhibiting the generation of oxide inclusions from the source.
Description
Technical Field
The invention belongs to the technical field of metallurgy, and relates to a clean steel smelting system and a clean steel smelting method.
Background
The current typical clean steel smelting process comprises the following steps: molten iron pretreatment → primary smelting furnace (electric arc furnace or converter) → external refining (LF/VD/VOD/RH) → continuous casting.
1) During the primary smelting furnace tapping process, the slag tapping is controlled by measures such as a slag blocking ball, a sliding plate for slag blocking, slag tapping detection and the like. However, practical application shows that a large amount of steel slag still enters the refining process. The primary smelting steel slag with high oxidizability enters a refining process and can pollute molten steel. Oxygen in deoxidized alloy reducing slag is usually adopted to change the physical and chemical properties of the steel slag, but the production cost is increased;
2) in the molten steel at the smelting end point of the primary smelting furnace, 400-800 ppm of O is usually dissolved. Therefore, a large amount of deoxidation alloy is added to deoxidize the molten steel in the tapping process of the primary smelting furnace. On the one hand, the yield of the alloy is reduced; in addition, the alloy elements are combined with oxygen to generate a large amount of inclusions which are difficult to remove, so that the quality of molten steel is influenced;
3) when smelting high-quality steel, refining facilities such as LF + VD or LF + RH are often adopted in a duplex way, and the treatment period of a single procedure reaches more than 30min, so that the natural temperature drop of molten steel is increased;
4) the turnover mode of loading molten steel by a steel ladle and hoisting the steel ladle by a large-scale casting crane is adopted, so that the design of a bearing structure of a workshop is complicated, and the investment is increased.
Disclosure of Invention
In view of the above, an object of the present invention is to provide a clean steel smelting system and method, which can prevent the highly-oxidized steel slag from entering the subsequent refining process, and reduce the consumption of alloy for deoxidizing the steel slag.
In order to achieve the purpose, the invention provides the following technical scheme:
a clean steel smelting system comprises a primary smelting furnace, a slag-steel separation device, a refining furnace and a continuous casting ladle which are sequentially arranged along the flowing direction of molten steel, wherein the slag-steel separation device is used for removing high-oxidizability steel slag in the molten steel so as to reduce the alloy consumption for deoxidizing and alloying the steel slag in the refining furnace.
Optionally, the slag-steel separation device further comprises a first diversion trench arranged between the primary smelting furnace and the slag-steel separation device, and a second diversion trench arranged between the slag-steel separation device and the refining furnace.
Optionally, one end of the first diversion trench is positioned below the steel tapping hole of the primary smelting furnace, and the other end of the first diversion trench is positioned above the slag-steel separation device; one end of the second diversion trench is positioned below the steel tapping hole of the slag-steel separation device, and the other end of the second diversion trench is positioned above the refining furnace.
Optionally, the first guide groove and the second guide groove are arranged obliquely downwards along the flowing direction of the molten steel, and the outlet end is open.
Optionally, the upper part of the first diversion trench, the slag-steel separation device and/or the second diversion trench is provided with a heat insulation cover.
Optionally, the upper part of the slag-steel separating device is provided with a slag outlet, and a slag tank is arranged below the slag outlet so that steel slag overflowing from the slag outlet enters the slag tank.
Optionally, the refining furnace is an induction heating vacuum refining furnace, and a steel tapping hole leading to the continuous casting ladle is formed in the bottom of the refining furnace.
A clean steel smelting method comprises the following steps: primary smelting, deslagging and refining, wherein the deslagging is used for removing high-oxidability steel slag in molten steel before refining, and deoxidation alloying operation is not carried out during primary smelting steel tapping and is carried out during refining.
Optionally, during refining, carbon deoxidation is performed in a vacuum environment, and after the carbon deoxidation is finished, alloying operation is performed.
Optionally, the temperature of molten steel refining is adjusted timely according to the requirement of the subsequent continuous casting temperature.
Optionally, the highly oxidizing steel slag in the molten steel is removed by a slag-steel separating device, and the tapping rate and the feeding rate of the slag-steel separating device are equivalent.
The invention has the beneficial effects that:
1. the slag-steel separation device is arranged, so that the high-oxidizability steel slag of the primary smelting furnace is prevented from entering a refining process, the possibility of pollution of molten steel is reduced, and the alloy consumption for deoxidizing the steel slag is reduced.
2. The invention cancels the deoxidation alloying operation in the tapping process of the primary smelting furnace, and carries out alloying after the vacuum carbon deoxidation in the refining furnace is finished, thereby improving the alloy yield and inhibiting the generation of oxide inclusions from the source.
3. The invention cancels the duplex of traditional refining facilities such as LF + VD or LF + RH and the like, adopts the induction heating vacuum refining furnace, can synchronously realize the operations of vacuum degassing and molten steel temperature adjustment, and reduces the refining period and the natural temperature drop of the molten steel;
4. in the invention, the molten steel is not circulated through the steel ladle in the whole smelting process, thereby reducing the bearing requirement of the workshop factory building column and being beneficial to reducing the civil engineering investment.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.
Drawings
For the purposes of promoting a better understanding of the objects, aspects and advantages of the invention, reference will now be made to the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic structural view of a clean steel smelting system according to the present invention.
Reference numerals: the steel slag separating device comprises a primary smelting furnace 1, a first diversion trench 2, a slag-steel separating device 3, a second diversion trench 4, a refining furnace 5, a continuous casting ladle 6, a slag pot 7, a slag-steel separating device steel tapping hole 8, a slag-steel separating device slag tapping hole 9, a primary smelting furnace steel tapping hole 10, an induction heating system 11 and a refining furnace steel tapping hole 12.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention in a schematic way, and the features in the following embodiments and examples may be combined with each other without conflict.
Wherein the showings are for the purpose of illustrating the invention only and not for the purpose of limiting the same, and in which there is shown by way of illustration only and not in the drawings in which there is no intention to limit the invention thereto; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.
The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc., based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of description, but it is not an indication or suggestion that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes, and are not to be construed as limiting the present invention, and the specific meaning of the terms may be understood by those skilled in the art according to specific situations.
Referring to fig. 1, a clean steel smelting system comprises a primary smelting furnace 1, a slag-steel separating device 3, a refining furnace 5 and a continuous casting ladle 6 which are sequentially arranged along the flowing direction of molten steel, wherein the slag-steel separating device 3 is used for removing high-oxidizability steel slag in the molten steel so as to inhibit the high-oxidizability steel slag of the primary smelting furnace from entering a refining process, the deoxidation alloying operation is not performed in the primary smelting furnace tapping process, and the alloying operation is performed after the vacuum carbon deoxidation in the refining furnace is finished.
According to the invention, the slag-steel separation device 3 is arranged, so that the high-oxidizability steel slag in the primary smelting furnace 1 is prevented from entering a refining process, the possibility of pollution of the molten steel is reduced, and the alloy consumption for steel slag deoxidation is reduced.
In order to avoid the turnover of molten steel through a ladle in the whole smelting process, the invention adopts the diversion trench to convey the molten steel, namely, a first diversion trench 2 is arranged between a primary smelting furnace 1 and a slag-steel separating device 3, and a second diversion trench 4 is arranged between the slag-steel separating device 3 and a refining furnace 5. The invention also reduces the bearing requirement of the workshop factory building column by arranging the diversion trench, and is beneficial to reducing the civil engineering investment.
The first guide groove 2 and the second guide groove 4 are arranged in a downward inclined manner along the flowing direction of the molten steel, and the outlet ends of the first guide groove and the second guide groove are open, so that the guide grooves realize flowing by utilizing the gravity of the molten steel. Specifically, one end of the first diversion trench 2 is positioned below the steel tapping hole of the primary smelting furnace 1, and the other end is positioned above the slag-steel separating device 3; one end of the second diversion trench 4 is positioned below the steel tapping hole of the slag-steel separating device 3, and the other end is positioned above the refining furnace 5.
In the method, the upper parts of the first guide groove 2, the slag-steel separating device 3 and/or the second guide groove 4 are/is provided with a heat insulation cover made of refractory materials so as to reduce the natural temperature drop of the molten steel.
The slag outlet is arranged at the upper part of the slag-steel separating device 3, and the slag tank 7 is arranged below the slag outlet, so that the steel slag overflowing from the slag outlet 9 of the slag-steel separating device enters the slag tank 7, and the automatic collection of the steel slag is realized.
The refining furnace 5 in the invention is an induction heating vacuum refining furnace, and the bottom of the refining furnace 5 is provided with a refining furnace steel outlet 12 leading to the continuous casting ladle 6. The invention can synchronously realize vacuum degassing and molten steel temperature adjustment operation in the refining process.
A clean steel smelting method comprises the following steps: primary smelting, deslagging and refining, wherein the deslagging is used for removing high-oxidability steel slag in molten steel before refining, and deoxidation alloying operation is not carried out during primary smelting steel tapping and is carried out during refining. The deoxidation alloying operation comprises the following steps: during refining, the carbon deoxidation is carried out in a vacuum environment, and the alloying operation is carried out after the carbon deoxidation is finished.
In order to reduce the refining period and inhibit the natural temperature drop of the molten steel, the invention timely adjusts the refining temperature of the molten steel according to the requirement of the subsequent continuous casting temperature, and the refining process synchronously realizes the operations of vacuum degassing and molten steel temperature adjustment.
In the invention, the high-oxidability steel slag in the molten steel is removed by the slag-steel separating device 3, and the steel tapping rate and the steel feeding rate of the slag-steel separating device 3 are equivalent.
When the smelting in the primary smelting furnace 1 is finished, the molten steel flows out from a steel outlet of the primary smelting furnace, is subjected to slag removal by the slag-steel separation device 3 and then enters the refining furnace 5. After the refining is finished, the molten steel flows into the continuous casting ladle 6 from a steel outlet at the bottom of the refining furnace.
According to the invention, the slag-steel separation device 3 is arranged, so that the high-oxidability steel slag in the primary smelting furnace 1 is prevented from entering a refining process, the possibility of pollution of the steel liquid is reduced, and the alloy consumption for steel slag deoxidation is reduced; the alloying operation is carried out after the vacuum carbon deoxidation in the refining furnace is finished, so that the alloy yield is improved, and the generation of oxide inclusions is also inhibited from the source; the vacuum degassing and molten steel temperature adjusting operation is synchronously realized in the refining process, and the refining period and the natural temperature drop of the molten steel are reduced. In addition, molten steel does not need to be circulated by steel ladles in the whole smelting process, the bearing requirement of workshop plant columns is favorably reduced, and the civil engineering investment is reduced.
Examples
The utility model provides a clean steel smelting system, includes that refining furnace 1, first guiding gutter 2, slag-steel separator 3, second guiding gutter 4, refining furnace 5, continuous casting package 6 and slag ladle 7, wherein refining furnace 5 adopts induction heating vacuum refining furnace.
The first diversion trench 2 is connected with the primary smelting furnace 1 and the slag-steel separating device 3, one end of the first diversion trench is positioned below the primary smelting furnace steel tapping hole 10, and the other end of the first diversion trench is positioned above the slag-steel separating device 3.
The second diversion trench 4 is connected with the slag-steel separation device 3 and the refining furnace 5, one end of the second diversion trench is positioned below the steel outlet 8 of the slag-steel separation device, and the other end of the second diversion trench is positioned above the refining furnace 5.
When the smelting in the primary smelting furnace 1 is finished, the molten steel flows out from a steel outlet 10 of the primary smelting furnace, passes through the first diversion trench 2 and enters the slag-steel separation device 3. After the molten steel in the slag-steel separating device 3 reaches a certain depth, the steel outlet 8 of the slag-steel separating device is opened, and the flow speed of the steel outlet 8 of the slag-steel separating device is equivalent to the steel outlet speed of the steel outlet 10 of the primary smelting furnace 1.
The molten steel flowing out of the steel tapping hole 8 of the slag-steel separating device enters the refining furnace 5 through the second diversion trench 4; when the amount of the steel slag in the slag-steel separating device 3 exceeds the capacity of the slag-steel separating device, the steel slag overflows from a slag outlet 9 of the slag-steel separating device into a slag tank 7.
The deoxidation alloying operation is not carried out in the primary refining furnace tapping process, and alloying is carried out after the vacuum carbon deoxidation period in the refining furnace 5 is finished. In the refining process, the temperature of the molten steel is adjusted in time by the induction heating system 11 of the refining furnace 5 according to the requirement of continuous casting corresponding to steel grades. After the refining is completed, the molten steel flows into the continuous casting ladle 6 from the refining furnace tap hole 12 located at the bottom of the refining furnace.
Finally, the above embodiments are only intended to illustrate the technical solutions of the present invention and not to limit the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all of them should be covered by the claims of the present invention.
Claims (10)
1. A clean steel smelting system is characterized in that: the steel slag deoxidation and alloying device comprises a primary smelting furnace, a slag steel separation device, a refining furnace and a continuous casting ladle which are sequentially arranged along the flowing direction of molten steel, wherein the slag steel separation device is used for removing high-oxidability steel slag in the molten steel so as to reduce the alloy consumption for deoxidation and alloying of the steel slag in the refining furnace.
2. The clean steel smelting system according to claim 1, wherein: the slag-steel separation device is characterized by also comprising a first diversion trench arranged between the primary smelting furnace and the slag-steel separation device, and a second diversion trench arranged between the slag-steel separation device and the refining furnace.
3. The clean steel smelting system according to claim 2, wherein: one end of the first diversion trench is positioned below a steel tapping hole of the primary smelting furnace, and the other end of the first diversion trench is positioned above the slag-steel separation device; one end of the second diversion trench is positioned below the steel tapping hole of the slag-steel separation device, and the other end of the second diversion trench is positioned above the refining furnace.
4. The clean steel smelting system according to claim 2, wherein: the first guide groove and the second guide groove are obliquely arranged downwards along the flowing direction of the molten steel, and the outlet ends of the first guide groove and the second guide groove are open.
5. The clean steel smelting system according to claim 2, wherein: and the upper parts of the first diversion trench, the slag-steel separation device and/or the second diversion trench are/is provided with a heat insulation cover.
6. The clean steel smelting system according to claim 1, wherein: the upper part of the slag-steel separating device is provided with a slag outlet, and a slag tank is arranged below the slag outlet so that steel slag overflowing from the slag outlet enters the slag tank.
7. The clean steel smelting system according to claim 1, wherein: the refining furnace is an induction heating vacuum refining furnace, and the bottom of the refining furnace is provided with a steel tapping hole leading to a continuous casting ladle.
8. The clean steel smelting method is characterized by comprising the following steps: primary smelting, deslagging and refining, wherein the deslagging is used for removing high-oxidability steel slag in molten steel before refining, and deoxidation alloying operation is not carried out during primary smelting steel tapping and is carried out during refining.
9. The clean steel smelting method according to claim 8, characterized by comprising the following steps: and adjusting the refining temperature of the molten steel in time according to the requirement of the subsequent continuous casting temperature.
10. The clean steel smelting method according to claim 8, characterized by comprising the following steps: the high-oxidizability steel slag in the molten steel is removed by a slag-steel separating device, and the tapping rate and the steel feeding rate of the slag-steel separating device are equivalent.
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| CN202110525305.4A CN113106196A (en) | 2021-05-11 | 2021-05-11 | Clean steel smelting system and method |
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| CN202110525305.4A CN113106196A (en) | 2021-05-11 | 2021-05-11 | Clean steel smelting system and method |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060272447A1 (en) * | 2005-05-06 | 2006-12-07 | Peaslee Kent D | Continuous steel production and apparatus |
| CN111172355A (en) * | 2020-01-10 | 2020-05-19 | 中冶赛迪工程技术股份有限公司 | Induction heating single-nozzle vacuum refining furnace and clean steel smelting process |
| CN214781960U (en) * | 2021-05-11 | 2021-11-19 | 中冶赛迪工程技术股份有限公司 | Clean steel smelting system |
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- 2021-05-11 CN CN202110525305.4A patent/CN113106196A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060272447A1 (en) * | 2005-05-06 | 2006-12-07 | Peaslee Kent D | Continuous steel production and apparatus |
| CN111172355A (en) * | 2020-01-10 | 2020-05-19 | 中冶赛迪工程技术股份有限公司 | Induction heating single-nozzle vacuum refining furnace and clean steel smelting process |
| CN214781960U (en) * | 2021-05-11 | 2021-11-19 | 中冶赛迪工程技术股份有限公司 | Clean steel smelting system |
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