CN110923404A - Low-cost desulfurization process for molten steel outside furnace - Google Patents
Low-cost desulfurization process for molten steel outside furnace Download PDFInfo
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- CN110923404A CN110923404A CN201911298021.5A CN201911298021A CN110923404A CN 110923404 A CN110923404 A CN 110923404A CN 201911298021 A CN201911298021 A CN 201911298021A CN 110923404 A CN110923404 A CN 110923404A
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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
- C21C7/064—Dephosphorising; Desulfurising
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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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- 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
- C21C7/064—Dephosphorising; Desulfurising
- C21C7/0645—Agents used for dephosphorising or desulfurising
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- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Analytical Chemistry (AREA)
- Treatment Of Steel In Its Molten State (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
The invention is applicable to the technical field of steelmaking process, provides a low-cost desulfurization process for molten steel outside a furnace, by adding the desulfurizer and the deoxidization alloy when tapping the steel for 1min by the converter and utilizing the strong stirring energy of high-temperature molten steel, calcium oxide and aluminum oxide slag are quickly formed at the molten steel flow rate of 300-450L/min, under the combined action of bottom blowing argon, upward bubble floating and downward steel flow, molten steel forms turbulent flow, the reaction area is enlarged, the mass transfer of sulfur on the steel slag interface is promoted, the reaction tends to be balanced, the tapping time is not less than 4min, and the desulfurizing agent comprises calcium oxide, silicon dioxide, aluminum oxide, aluminum and calcium fluoride.
Description
Technical Field
The invention belongs to the technical field of steelmaking processes, and particularly relates to a low-cost desulfurization process for molten steel outside a furnace.
Background
Sulfur is a harmful element in the steel making process, and is brought by molten iron. When the sulfur content of the metallurgical steel seed finished product is high, on one hand, cracks are easily generated on the surface of a casting blank; on the other hand, sulfur is easy to enrich to the center of the casting blank in the process of casting blank solidification, and the center quality of the casting blank is deteriorated. Therefore, the sulfur content as a harmful element in molten steel must be strictly controlled.
At present, the domestic steel-making link generally adopts a desulfurization process flow as follows: molten iron desulphurization → desulphurization in the smelting process after the molten iron enters the converter → desulphurization after the molten steel is refined into LF. Although the sulfur content in the molten steel can be controlled within 0.010 percent by the conventional desulfurization process, the total production flow is long, the production cost is high, and the reduction of the cost of steel per ton is not facilitated.
Disclosure of Invention
The invention provides a low-cost desulfurization process for molten steel outside a furnace, and aims to solve the problems of long overall production process, high production cost and inconvenience for reducing the cost of steel per ton.
The invention is realized in this way, a low-cost desulfurization process of molten steel outside the furnace, including the following steps:
1) and (3) adding a desulfurizer and a deoxidation alloy when tapping of the converter is carried out for 1min, and rapidly forming calcium oxide and aluminum oxide slag at the flow rate of the molten steel of 300-450L/min by utilizing the strong stirring energy of the high-temperature molten steel.
2) Under the combined action of bottom blowing argon, upward bubble floating and downward steel flow, molten steel forms turbulent flow, the reaction area is enlarged, the mass transfer of sulfur on the steel slag interface is promoted, the reaction tends to be balanced, and the steel tapping time is not less than 4 min.
Preferably, the desulfurizing agent comprises: calcium oxide, silicon dioxide, aluminum oxide, aluminum and calcium fluoride.
Preferably, the mass of the calcium oxide is not less than 40% of the total mass of the desulfurizer, the mass of the silicon dioxide is not more than 4% of the total mass of the desulfurizer, the mass of the aluminum oxide is 20% -35% of the total mass of the desulfurizer, the mass of the aluminum is not less than 12% of the total mass of the desulfurizer, and the mass of the calcium fluoride is not more than 3% of the total mass of the desulfurizer.
Preferably, the diameter of the particles in the desulfurizing agent is 5 mm-20 mm.
Preferably, the mass content of water in the desulfurizing agent is less than 0.5%.
Preferably, the time for blowing the argon is not less than 8 min.
Preferably, in the step 2), during tapping, a slag blocking plug or a slag blocking ball is arranged at the tapping hole to reduce the slag dropping amount.
Preferably, the melting point of the desulfurizing agent is not higher than 1380 ℃.
Compared with the prior art, the invention has the beneficial effects that: the low-cost desulfurization process for the molten steel outside the converter fully utilizes the strong impact stirring kinetic energy of the high-temperature molten steel on deoxidation and slagging materials in the tapping process of the converter to form high-alkalinity low-melting-point desulfurization slag, so that a slag washing effect is generated on the molten steel, and the end-point sulfur content is controlled at a lower level.
Drawings
FIG. 1 is a schematic process flow diagram of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and 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.
Example one
Referring to fig. 1, an embodiment provides a technical solution: a low-cost desulfurization process for molten steel outside a furnace comprises the following steps:
1) preparing a desulfurizing agent, wherein the desulfurizing agent comprises the following components in percentage by mass: 50 parts of calcium oxide, 4 parts of silicon dioxide, 30 parts of aluminum oxide, 12 parts of aluminum and 4 parts of calcium fluoride, the diameter of particles in the desulfurizer is 5-20 mm, the mass content of water in the desulfurizer is less than 0.5%, and the melting point of the desulfurizer is not higher than 1380 ℃. And (3) adding a desulfurizer and a deoxidation alloy when tapping of the converter is carried out for 1min, and rapidly forming calcium oxide and aluminum oxide slag at the flow rate of the molten steel of 300-450L/min by utilizing the strong stirring energy of the high-temperature molten steel.
2) Under the combined action of bottom blowing argon, floating bubbles and downward flowing steel flow, molten steel forms turbulent flow, the reaction area is enlarged, the mass transfer of sulfur on the steel slag interface is promoted, the reaction tends to be balanced, the steel tapping time is not less than 4min, the argon blowing time is not less than 8min, a slag blocking plug or a slag blocking ball is arranged at a steel tapping hole to reduce the slag dropping amount, and the thickness of the steel slag is not more than 5 mm.
The good steel slag mixing and flushing effect is created, and top slag with strong desulfurization capability is formed. The sulfur content ratio between slag and steel is gradually increased along with the increase of the sulfur capacity and is gradually reduced along with the increase of the oxidizing property of slag. Therefore, partial calcium oxide can be properly supplemented when the alkalinity of the slag is improved, and aluminum powder can be properly supplemented when the iron oxide in the slag is reduced, so that the iron oxide and the manganese oxide in the slag are reduced, the activity of the calcium oxide is improved, and the desulfurization reaction can be carried out towards the direction favorable for desulfurization.
The low-cost desulfurization process for the molten steel outside the converter fully utilizes the strong impact stirring kinetic energy of the high-temperature molten steel on deoxidation and slagging materials in the tapping process of the converter to form high-alkalinity low-melting-point desulfurization slag, so that a slag washing effect is generated on the molten steel, and the end-point sulfur content is controlled at a lower level.
Example two
The embodiment provides a technical scheme: a low-cost desulfurization process for molten steel outside a furnace comprises the following steps:
1) preparing a desulfurizing agent, wherein the desulfurizing agent comprises the following components in percentage by mass: 60 parts of calcium oxide, 4 parts of silicon dioxide, 20 parts of aluminum oxide, 12 parts of aluminum and 4 parts of calcium fluoride, wherein the diameter of particles in the desulfurizer is 5-20 mm, the mass content of water in the desulfurizer is less than 0.5%, and the melting point of the desulfurizer is not higher than 1380 ℃. And (3) adding a desulfurizer and a deoxidation alloy when tapping of the converter is carried out for 1min, and rapidly forming calcium oxide and aluminum oxide slag at the flow rate of the molten steel of 300-450L/min by utilizing the strong stirring energy of the high-temperature molten steel.
2) Under the combined action of bottom blowing argon, floating bubbles and downward flowing steel flow, molten steel forms turbulent flow, the reaction area is enlarged, the mass transfer of sulfur on the steel slag interface is promoted, the reaction tends to be balanced, the steel tapping time is not less than 4min, the argon blowing time is not less than 8min, a slag blocking plug or a slag blocking ball is arranged at a steel tapping hole to reduce the slag dropping amount, and the thickness of the steel slag is not more than 5 mm.
The good steel slag mixing and flushing effect is created, and top slag with strong desulfurization capability is formed. The sulfur content ratio between slag and steel is gradually increased along with the increase of the sulfur capacity and is gradually reduced along with the increase of the oxidizing property of slag. Therefore, partial calcium oxide can be properly supplemented when the alkalinity of the slag is improved, and aluminum powder can be properly supplemented when the iron oxide in the slag is reduced, so that the iron oxide and the manganese oxide in the slag are reduced, the activity of the calcium oxide is improved, and the desulfurization reaction can be carried out towards the direction favorable for desulfurization.
Compared with the first embodiment, the content of calcium oxide and aluminum in the desulfurizing agent is increased, so that the alkalinity of the steel slag can be increased, and the content of iron oxide in the steel slag can also be reduced.
EXAMPLE III
The embodiment provides a technical scheme: a low-cost desulfurization process for molten steel outside a furnace comprises the following steps:
1) preparing a desulfurizing agent, wherein the desulfurizing agent comprises the following components in percentage by mass: 40 parts of calcium oxide, 4 parts of silicon dioxide, 35 parts of aluminum oxide, 17 parts of aluminum and 4 parts of calcium fluoride, the diameter of particles in the desulfurizer is 5-20 mm, the mass content of water in the desulfurizer is less than 0.5%, and the melting point of the desulfurizer is not higher than 1380 ℃. And (3) adding a desulfurizer and a deoxidation alloy when tapping of the converter is carried out for 1min, and rapidly forming calcium oxide and aluminum oxide slag at the flow rate of the molten steel of 300-450L/min by utilizing the strong stirring energy of the high-temperature molten steel.
2) Under the combined action of bottom blowing argon, floating bubbles and downward flowing steel flow, molten steel forms turbulent flow, the reaction area is enlarged, the mass transfer of sulfur on the steel slag interface is promoted, the reaction tends to be balanced, the steel tapping time is not less than 4min, the argon blowing time is not less than 8min, a slag blocking plug or a slag blocking ball is arranged at a steel tapping hole to reduce the slag dropping amount, and the thickness of the steel slag is not more than 5 mm.
The good steel slag mixing and flushing effect is created, and top slag with strong desulfurization capability is formed. The sulfur content ratio between slag and steel is gradually increased along with the increase of the sulfur capacity and is gradually reduced along with the increase of the oxidizing property of slag. Therefore, partial calcium oxide can be properly supplemented when the alkalinity of the slag is improved, and aluminum powder can be properly supplemented when the iron oxide in the slag is reduced, so that the iron oxide and the manganese oxide in the slag are reduced, the activity of the calcium oxide is improved, and the desulfurization reaction can be carried out towards the direction favorable for desulfurization.
Compared with the first embodiment, the content of aluminum oxide and aluminum oxide in the desulfurizer is increased, so that the content of iron oxide and manganese oxide in slag can be further reduced, the activity of calcium oxide is improved, and the desulfurization reaction is carried out towards the direction more favorable for desulfurization.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (8)
1. A low-cost desulfurization process for molten steel outside a furnace is characterized in that: the method comprises the following steps:
1) and (3) adding a desulfurizer and a deoxidation alloy when tapping of the converter is carried out for 1min, and rapidly forming calcium oxide and aluminum oxide slag at the flow rate of the molten steel of 300-450L/min by utilizing the strong stirring energy of the high-temperature molten steel.
2) Under the combined action of bottom blowing argon, upward bubble floating and downward steel flow, molten steel forms turbulent flow, the reaction area is enlarged, the mass transfer of sulfur on the steel slag interface is promoted, the reaction tends to be balanced, and the steel tapping time is not less than 4 min.
2. The process for low-cost desulfurization of molten steel outside a furnace of claim 1, characterized in that: the desulfurizing agent comprises: calcium oxide, silicon dioxide, aluminum oxide, aluminum and calcium fluoride.
3. The process for low-cost desulfurization of molten steel outside a furnace of claim 2, characterized in that: the mass of the calcium oxide is not less than 40% of the total mass of the desulfurizer, the mass of the silicon dioxide is not more than 4% of the total mass of the desulfurizer, the mass of the aluminum oxide is 20% -35% of the total mass of the desulfurizer, the mass of the aluminum is not less than 12% of the total mass of the desulfurizer, and the mass of the calcium fluoride is not more than 3% of the total mass of the desulfurizer.
4. The process for low-cost desulfurization of molten steel outside a furnace of claim 2, characterized in that: the diameter of the granules in the desulfurizer is 5 mm-20 mm.
5. The process for low-cost desulfurization of molten steel outside a furnace of claim 1, characterized in that: the mass content of water in the desulfurizer is less than 0.5%.
6. The process for low-cost desulfurization of molten steel outside a furnace of claim 1, characterized in that: the time for blowing argon is not less than 8 min.
7. The process for low-cost desulfurization of molten steel outside a furnace of claim 1, characterized in that: in the step 2), during tapping, a slag blocking plug or a slag blocking ball is arranged at the tapping hole to reduce the slag discharge.
8. The process for low-cost desulfurization of molten steel outside a furnace of claim 1, characterized in that: the melting point of the desulfurizer is not higher than 1380 ℃.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911298021.5A CN110923404A (en) | 2019-12-17 | 2019-12-17 | Low-cost desulfurization process for molten steel outside furnace |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201911298021.5A CN110923404A (en) | 2019-12-17 | 2019-12-17 | Low-cost desulfurization process for molten steel outside furnace |
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| CN110923404A true CN110923404A (en) | 2020-03-27 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114622053A (en) * | 2022-03-31 | 2022-06-14 | 宝武集团鄂城钢铁有限公司 | Smelting method for efficient desulfurization at converter end point |
Citations (3)
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|---|---|---|---|---|
| CN101798612A (en) * | 2010-04-12 | 2010-08-11 | 首钢总公司 | Process for washing, pre-desulfurizing and refining tapping steel slag of converter |
| CN103233098B (en) * | 2013-05-13 | 2016-01-20 | 涟源市飞达冶金炉料厂 | A kind of straight upper using method of wash heat mixing material in converter tapping |
| CN105803148A (en) * | 2016-03-22 | 2016-07-27 | 首钢总公司 | Smelting method for low-sulfur steel |
-
2019
- 2019-12-17 CN CN201911298021.5A patent/CN110923404A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101798612A (en) * | 2010-04-12 | 2010-08-11 | 首钢总公司 | Process for washing, pre-desulfurizing and refining tapping steel slag of converter |
| CN103233098B (en) * | 2013-05-13 | 2016-01-20 | 涟源市飞达冶金炉料厂 | A kind of straight upper using method of wash heat mixing material in converter tapping |
| CN105803148A (en) * | 2016-03-22 | 2016-07-27 | 首钢总公司 | Smelting method for low-sulfur steel |
Non-Patent Citations (3)
| Title |
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| 张伟 等: "转炉钢水炉外脱硫剂成分优化及应用实践", 《中国新技术新产品》 * |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114622053A (en) * | 2022-03-31 | 2022-06-14 | 宝武集团鄂城钢铁有限公司 | Smelting method for efficient desulfurization at converter end point |
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