CN1087034C - Technology for desulfurizing molten steel in enclosed ladle by spraying powder - Google Patents
Technology for desulfurizing molten steel in enclosed ladle by spraying powder Download PDFInfo
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- CN1087034C CN1087034C CN99122341A CN99122341A CN1087034C CN 1087034 C CN1087034 C CN 1087034C CN 99122341 A CN99122341 A CN 99122341A CN 99122341 A CN99122341 A CN 99122341A CN 1087034 C CN1087034 C CN 1087034C
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- steel
- cover
- molten steel
- impregnating cover
- powder
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Abstract
The present invention relates to a metallurgy of iron and steel technique which belongs to the field of secondary refining processing. When liquid steel is secondarily refined, a fire-resistant material cover is immersed in a steel storage tank; the residual slag in the cover is processed into reducing slag, the slag is removed from the immersion cover by argon blown from the bottom, and nitrogen partial pressure in the cover is reduced to a certain limit by argon sealing; a spraying gun is inserted into the immersion cover, liquid steel desulphurization is carried out by spraying a composite desulphurizing agent. The technique has the advantages of high reaction speed of conventional powder spraying and desulphurization, and high efficiency; secondary oxidation and azotation caused by spraying are avoided when the liquid steel writhes. The technique is suitable for producing low-sulphur steel with the content of 0.003% in large scale and also has the advantages of small construction investment, low production cost and good popularization and utilization prospect.
Description
The invention belongs to the external refining process field of ferrous metallurgy technology.At present, the common method of carrying out molten steel desulfurizing in steel teeming ladle has two kinds: the first is removed into powdery or block sweetening agents such as lime, fluorites to the molten steel face in the steel teeming ladle of band heat riser, carries out desulfurization by slag steel interfacial mass transfer; Add-on is generally 8-15kg/t, and refining time is 30-50min, generally sulphur in the steel can be reduced to 10ppm.It two is with sweetening agent (CaO, CaCO with carrier gas
3, CaF
2Deng) spraying into molten steel inside, sweetening agent directly contacts with sulphur in the molten steel and carries out desulfurization; Straying quatity is generally 6-10kg/t, and the winding-up time is 5-10min, generally sulphur in the steel can be reduced to 10ppm.
The shortcoming that is sprinkled into sweetening agent in steel teeming ladle is: slag steel interfacial mass transfer speed is slow, and desulfurization time is long, causes productivity low, and steel teeming ladle need possess the heat temperature raising condition simultaneously.
The shortcoming that sweetening agent is sprayed into molten steel is: the violent stirring effect in the winding-up process, and make the part molten steel seethe and be exposed in the air, cause molten steel easily to inhale nitrogen and secondary oxidation; Powder injection desulphurization efficient is subjected to the influence of the interior first slag rerum natura (oxidation susceptibility) of steel teeming ladle and the quantity of slag bigger simultaneously.For addressing this problem, adopted blowing desulfurization agent desulfurization (as RH-KB) under the vacuum, but because it is higher to obtain the investment and the production cost of vacuum, generally being used for high quality steel and special steel must produce, and can not be used for straight carbon steel and low alloy steel and carry out scale operation.
The objective of the invention is and can produce low-sulfur and super low sulfur steel economical, efficiently, exploitation is fit to the secondary refining process of scale operation straight carbon steel and low alloy steel desulfurization.
Invention comprises steel teeming ladle impregnating cover, intrusive mood refractory materials powder monitor, steel teeming ladle Argon device, composite desulfurizing agent.The steel teeming ladle impregnating cover is inserted molten steel, molten steel temperature is 1650-1700 ℃, in impregnating cover, add earlier reduced blast furnace, feed argon gas to powder monitor again, the decline powder monitor inserts molten steel, blowing desulfurization pulvis immediately, regulate the argon bottom-blowing parameter and carry out the bottom blowing stirring, the oxygen partial pressure in the impregnating cover is reduced to 0.005Mpa, and the concentration expressed in percentage by volume of oxygen concn is 5-12%, nitrogen partial pressure is reduced to 0.02Mpa, the concentration expressed in percentage by volume of nitrogen concentration is 15-25%, and the treatment time of powder injection desulphurization is 5-15min, 30-50 ℃ of molten steel temperature decline, the liquid steel desulphurization rate is 60-80%, and molten steel terminal point sulfur content reaches 0.004-0.001%.
The present invention adds reduction slag charge CaO:5-30kg/t, CaF in impregnating cover
2: 2-10kg/t, Al
2O
3: 0-5kg/t, SiC:0.5-3kg/t, the main component that the composition of adjusting slag in the back cover is is (%CaO)=45-66, (%SiO
2)=15-26, (%FeO+MnO)≤1, (%MgO)=3-10, (%Al
2O
3)=5-15, (%CaF
2)=1-3.
The impregnating cover insertion molten steel degree of depth is 100mm-400mm among the present invention, and the depth of penetration of refractory materials powder monitor is 0-1800mm, and the winding-up argon flow amount is 0.005-0.1Nm
3/ t.min, pressure are 0.3-0.5Mpa, the winding-up amount 0.2-2kg/t.min of sweetening agent, and the BOTTOM ARGON BLOWING flow is 0.005-0.05Nm
3/ t.min.
Refractory materials powder monitor of the present invention was jetted argon gas 1-3 minute at the interface at the slag steel earlier, and powder monitor being inserted the molten steel degree of depth is 200-1800mm again, and oxygen concn is volume percent 5-12% in blowing desulfurization pulvis 5-12 minute, sweetening process impregnating cover.
Desulfurization powder composition of the present invention is calculated by mass percentage, and the main component of sweetening agent is CaO (60-80%), CaF
2(5-20%), CaCO
3(5-10%), BaCO
3(1-6%), Na
2CO
3(1-6%), SiC (1-5%) etc.The granularity of sweetening agent is 0.0375-0.075mm.
The diameter of impregnating cover of the present invention is the 1/3-1/2D (D is the steel teeming ladle diameter) of steel teeming ladle diameter, the height H of cover
21/2-3/4H for the steel teeming ladle height
1The hatch of powder monitor is located at the central position at impregnating cover top, and diameter is 50-200mm.Charge cavity and venting hole are a hole, and diameter is the 1/4-1/6D of impregnating cover diameter
1, be positioned at apart from impregnating cover center 1/4D
1The bottom blowing device is located at the central position of ladle bottom corresponding to impregnating cover.
Fig. 1 of the present invention comprises steel teeming ladle (1), impregnating cover (2), powder monitor hole (3), refractory submerged material powder monitor (4), charge cavity (double as venting hole) (5), slag liquid (6), molten steel (7), steel teeming ladle Bottom Argon Blowing Device (8).The powder monitor hole that the impregnating cover top is provided with is positioned at the central position at impregnating cover top, and diameter is 50-200mm, and charge cavity double as venting hole is in the top center 3/4D of impregnating cover
1, D
1Be the impregnating cover diameter, the charge cavity diameter is the 1/4-1/6D of impregnating cover diameter
1
The present invention is when Liquid Steel Secondary Refining, in steel teeming ladle, a refractory materials cover is inserted molten steel, the impregnating cover on position is in the center of steel teeming ladle in the scope of center 1/6D, the depth of penetration of impregnating cover is the 1/5-1/6 of the molten steel degree of depth, the diameter of impregnating cover is the 1/3-1/2D of steel teeming ladle diameter, and the height of impregnating cover is the 1/2-3/4 of steel teeming ladle height.The refractory materials of cover is a high alumina matter, and wall thickness is 40-100mm.The vertical refractory materials spray gun that inserts in impregnating cover.
The present invention adopts high alumina matter or corundum matter powder monitor (spray gun exit diameter d
1Be 15-50mm, be the 1/50-1/100D of impregnating cover diameter
1), impregnating cover is inserted molten steel, again spray gun is inserted into slag steel position at the interface and carries out Argon, argon flow amount is 0.005-0.2Nm
3/ t.min, pressure are 0.3-0.7Mpa; Diffuse type gas permeable brick Argon is adopted in the bottom simultaneously, and argon flow amount is 0.005-0.05Nm
3/ t.min, pressure are 0.3-0.7Mpa, and the position of gas permeable brick is in the steel teeming ladle center in the scope of center 1/6D.By the rising of bottom and top argon gas stream, can reduce oxygen, nitrogen gas concn in the cover.According to experimental result, every m in the impregnating cover
3Spray into 2-3Nm
3Behind the argon gas, oxygen concentration can drop to 5%, nitrogen gas concn drops to 20%.
The original slag of steel teeming ladle is the oxidisability slag.Make the quantity of slag drop to below 0.5% of molten steel amount by pushing off the slag (converter relies on slag-blocking ball pushing off the slag, electric furnace to rely on eccentric bottom tapping).Before impregnating cover inserted molten steel, (argon flow amount was 0.1-1.0Nm by steel teeming ladle bottom Argon
3/ min), slag on the molten steel face can be blown open, form the exposed eye of molten steel of a no slag, the area of exposed eye is mainly determined exposed area at present by the decisions such as character of flow, pressure and the steel teeming ladle size of BOTTOM ARGON BLOWING, the molten steel degree of depth, molten steel by numerical simulation and experiment.
Impregnating cover diameter D
1Be by the exposed eye of molten steel diameter D
2Determine, that is: D
1≤ D
2After adopting impregnating cover, the amount of slag in the cover according to the experience of steel-making CAS technology, is generally the 0.1%-0.3% of molten steel amount.The impregnating cover top is provided with gun hole, charge cavity.Gun hole is positioned at the center at impregnating cover top, and its diameter is 50-200mm, and charge cavity also is a venting hole, is positioned at the impregnating cover top far from center 3/4D
1, its diameter is the 1/4-1/6D of impregnating cover diameter
1
The present invention adopts tapping pushing off the slag technology and steel teeming ladle impregnating cover initial slag all can not be got rid of, and last slag main component is [%CaO]=30-50 in the cover, [%SiO
2]=10-25, [%FeO+MnO]=15-25, [%MgO]=5-10.[be mainly CaO (60-80% of slag total amount), CaF by in cover, adding lime base reducing slag
2(5-20%), Al
2O
3(3-10%), CaCO
3(5-10%), SiC (2-5%), etc.].Original slag is carried out denaturing treatment, make it become the reductibility slag.The quantity of slag that adds reducing slag in impregnating cover is the 0.3-1.0% of molten steel amount, and the main component of its slag is [%CaO]=40-60 behind the formation reducing slag, [%SiO
2]=15-25, [%FeO+MnO]≤1, [%MgO]=3-8, [%Al
2O
3]=5-15.
The present invention inserts molten steel with high alumina matter in the impregnating cover or corundum matter spray gun, and spray gun inserts the molten steel degree of depth greater than 200mm.As the carrier gas composite desulfurizing agent of jetting, the flow of argon gas is 0.1-1.0Nm with argon gas
3/ t.h, the winding-up amount of sweetening agent is 2-10kg/t, the winding-up time is 5-10min.The main component of sweetening agent is CaO (60-80%), CaF
2(5-20%), CaCO
3(5-10%), BaCO
3(1-6%), Na
2CO
3(1-6%), SiC (1-5%) etc., the granularity of sweetening agent is 0.0375-0.075mm.
The temperature of the winding-up process of liquid steel desulphurization of the present invention is 1650-1700 ℃, and temperature drop is 30-50 ℃, and original sulphur is 50-120ppm, and desulfurization degree is 60-90%, the minimum 10ppm that drops to of molten steel sulphur content.
Adopt above method, solved blowing desulfurization agent process molten steel and under atmosphere, inhaled nitrogen and secondary oxidation problem, by the blowing desulfurization experiment confirm, molten steel nitrogen increased amount＜5ppm, molten steel oxygenation amount＜3ppm.
Compare with existing refinery practice, because sweetening process adopts the airtight method of impregnating cover, carrier gas with BOTTOM ARGON BLOWING and powder monitor is that argon gas dusts, can make molten steel be in the rough vacuum condition, the oxygen level of molten steel and freeboard gas is low, for liquid steel desulphurization provides good condition, therefore accelerate the liquid steel desulphurization process and prevented the molten steel secondary oxidation and suction nitrogen, so technology for desulfurizing molten steel in enclosed ladle by spraying powder has the advantage that conventional powder injection desulphurization speed of response is fast, efficient is high, molten steel secondary oxidation when having avoided simultaneously winding-up to cause molten steel to seethe again and suction nitrogen.Adopt impregnating cover powder injection desulphurization technology, desulphurization cost reduces, and the ton steel is expected to reduce 10-50 unit.This technology investment is less relatively, production cost is lower, is fit on a large scale molten steel sulphur is removed to 0.003% level.Has good popularizing application prospect.
Accompanying drawing 1 of the present invention is the longitudinal sectional drawing of steel teeming ladle impregnating cover molten steel powder injection desulphurization device sketch.Diameter is the 1/4-1/6D of impregnating cover diameter
1
Embodiment of the present invention are carried out on the 30t steel teeming ladle, steel teeming ladle diameter 1800mm, steel teeming ladle height 2400mm, impregnating cover inserts the central authorities of steel teeming ladle, the diameter of impregnating cover is 900mm, and the height of impregnating cover is 1200mm, and the plug in rifle hole of impregnating cover is 100mm, charge cavity is 200mm, and the external diameter of spray gun is 80mm.The composition of sweetening agent is CaO (65%), CaF
2(10%), CaCO
3(9%), BaCO
3(2%), Na
2CO
3(2%), SiC (2%) etc.The granularity of sweetening agent is 0.075mm.
The winding-up starting condition be, the initial sulphur in the steel is 70-90ppm, the molten steel equilibrium temperature is 1700 ℃.
The preceding spray gun that dusts is inserted into slag steel position at the interface and carries out Argon, and argon flow amount is 0.05Nm
3/ t.min, pressure are 0.4Mpa, and argon blowing time is 3min.The position of gas permeable brick is in the center of steel teeming ladle, and argon blowing rate is 0.05Nm
3/ t.min, pressure are 0.4Mpa.The amount of dusting of top spray sweetening agent is 8-10kg/t, and the winding-up time is 5min.
Terminal point sulphur average out to 25ppm in the steel after the blowing desulfurization agent, nitrogen increased amount is 1-2ppm, molten steel temperature descends 30 ℃.
Claims (6)
1. technology for desulfurizing molten steel in enclosed ladle by spraying powder is characterized in that using steel teeming ladle impregnating cover, refractory submerged material powder monitor, the steel ladle bottom argon blowing device, and the steel teeming ladle impregnating cover is provided with the powder monitor hatch, charge cavity and venting hole; The steel teeming ladle impregnating cover is inserted molten steel, molten steel temperature is 1650-1700 ℃, in impregnating cover, add earlier reduced blast furnace, feed argon gas to powder monitor again, the decline powder monitor inserts molten steel, the pulvis of blowing desulfurization agent immediately, regulate the argon bottom-blowing parameter and carry out the bottom blowing stirring, the oxygen partial pressure in the impregnating cover is reduced to 0.005Mpa, and the concentration expressed in percentage by volume of oxygen concn is 5-12%, nitrogen partial pressure is reduced to 0.02Mpa, the concentration expressed in percentage by volume of nitrogen concentration is 15-25%, and the treatment time of powder injection desulphurization is 5-15min, 30-50 ℃ of molten steel temperature decline, the liquid steel desulphurization rate is 60-80%, and molten steel terminal point sulfur content reaches 0.004-0.001%.
2. according to the described powder injection desulphurization method of claim 1, it is characterized in that in impregnating cover, adding reduction slag charge CaO:5-30kg/t, CaF
2: 2-10kg/t, Al
2O
3: 0-5kg/t, SiC:0.5-3kg/t, the main component that the composition of adjusting slag in the back cover is is (%CaO)=45-66, (%SiO
2)=15-26, (%FeO+MnO)≤1, (%MgO)=3-10, (%Al
2O
3)=5-15, (%CaF
2)=1-3.
3. according to the described powder injection desulphurization method of claim 1, it is characterized in that it is 100mm-400mm that the steel teeming ladle impregnating cover inserts the molten steel degree of depth, the depth of penetration of refractory materials powder monitor is 0-1800mm, and the winding-up argon flow amount is 0.005-0.1Nm
3/ t.min, pressure are 0.3-0.5Mpa, the winding-up amount 0.2-2kg/t.min of sweetening agent; The BOTTOM ARGON BLOWING flow is 0.005-0.05Nm
3/ t.min.
4. according to claim 1,3 described powder injection desulphurization methods, it is characterized in that the refractory materials powder monitor jetted argon gas 1-3 minute at the interface at the slag steel earlier, powder monitor being inserted the molten steel degree of depth is 200-1800mm again, oxygen concn is volume percent 5-12% in blowing desulfurization pulvis 5-12 minute, sweetening process impregnating cover.
5. according to the described powder injection desulphurization method of claim 1, it is characterized in that the desulfurization powder composition is by mass percentage, the main component that is mainly sweetening agent is CaO (60-80%), CaF
2(5-20%), CaCO
3(5-10%), BaCO
3(1-6%), Na
2CO
3(1-6%), SiC (1-5%) etc., the granularity of sweetening agent is 0.0375-0.075mm.
6. device of implementing the described method of claim 1, it is characterized in that steel teeming ladle (1), impregnating cover (2), refractory submerged material powder monitor (5), steel teeming ladle Bottom Argon Blowing Device (8), the diameter of impregnating cover is the 1/3-1/2 of steel teeming ladle diameter, the height of the cover of cover is the 1/2-3/4 of steel teeming ladle height, the hatch of powder monitor is located at the central position at impregnating cover top, diameter is 50-200mm, charge cavity and venting hole are a hole, diameter is the 1/4-1/6 of impregnating cover diameter, be positioned at the impregnating cover diameter apart from impregnating cover center 1/4, the bottom blowing device is located at the central position of ladle bottom corresponding to impregnating cover.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN99122341A CN1087034C (en) | 1999-11-02 | 1999-11-02 | Technology for desulfurizing molten steel in enclosed ladle by spraying powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN99122341A CN1087034C (en) | 1999-11-02 | 1999-11-02 | Technology for desulfurizing molten steel in enclosed ladle by spraying powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1294199A CN1294199A (en) | 2001-05-09 |
| CN1087034C true CN1087034C (en) | 2002-07-03 |
Family
ID=5282453
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN99122341A Expired - Fee Related CN1087034C (en) | 1999-11-02 | 1999-11-02 | Technology for desulfurizing molten steel in enclosed ladle by spraying powder |
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|---|---|
| CN (1) | CN1087034C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2653743C1 (en) * | 2017-03-20 | 2018-05-14 | Публичное акционерное общество "Северсталь" (ПАО "Северсталь") | Method of mixing steel in the metallurgical unit |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2197540C2 (en) * | 2001-04-24 | 2003-01-27 | Хлопонин Виктор Николаевич | Method of mixing steel in ladle |
| RU2208054C1 (en) * | 2002-04-03 | 2003-07-10 | Техком Импорт Экспорт Гмбх | Method for mixing steel in ladle |
| LU90924B1 (en) * | 2002-05-24 | 2003-11-25 | Wurth Paul Sa | Metallurgical treatment process on a metal bath |
| CN102002554B (en) * | 2009-08-28 | 2012-04-25 | 宝山钢铁股份有限公司 | Rapid desulfurization refining method for ladle furnace |
| CN102337377A (en) * | 2011-08-23 | 2012-02-01 | 莱芜钢铁集团有限公司 | Molten steel wire feeding device and wire feeding method |
| CN102559998A (en) * | 2012-02-03 | 2012-07-11 | 北京首钢国际工程技术有限公司 | Technology for online dusting desulfuration of steel ladles |
| CN102747190A (en) * | 2012-07-30 | 2012-10-24 | 重庆钢铁(集团)有限责任公司 | Deoxygenation modifier for molten steel |
| CN105624367B (en) * | 2014-12-01 | 2017-07-21 | 鞍钢股份有限公司 | Refining device and method for controlling nitrogen content of molten steel |
| CN114606364B (en) * | 2022-02-08 | 2023-08-11 | 首钢集团有限公司 | KR powder spraying molten iron pretreatment method |
| CN115976301B (en) * | 2023-02-01 | 2023-08-08 | 江苏省镔鑫钢铁集团有限公司 | Steel ladle nitrogen increasing equipment for increasing strength of anti-seismic steel bars and control method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1045128A (en) * | 1989-02-24 | 1990-09-05 | 曼内斯曼股份公司 | The method and apparatus of treatment of metal in vacuum |
| CN2235449Y (en) * | 1994-04-12 | 1996-09-18 | 鞍山钢铁公司 | Impregnation tube used in steel ladle refining |
-
1999
- 1999-11-02 CN CN99122341A patent/CN1087034C/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1045128A (en) * | 1989-02-24 | 1990-09-05 | 曼内斯曼股份公司 | The method and apparatus of treatment of metal in vacuum |
| CN2235449Y (en) * | 1994-04-12 | 1996-09-18 | 鞍山钢铁公司 | Impregnation tube used in steel ladle refining |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2653743C1 (en) * | 2017-03-20 | 2018-05-14 | Публичное акционерное общество "Северсталь" (ПАО "Северсталь") | Method of mixing steel in the metallurgical unit |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1294199A (en) | 2001-05-09 |
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