CN103014242B - Smelting slagging agent and smelting slagging method adopting AOD (Argon Oxygen Decarburization) double slag process - Google Patents
Smelting slagging agent and smelting slagging method adopting AOD (Argon Oxygen Decarburization) double slag process Download PDFInfo
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- CN103014242B CN103014242B CN201210548218.1A CN201210548218A CN103014242B CN 103014242 B CN103014242 B CN 103014242B CN 201210548218 A CN201210548218 A CN 201210548218A CN 103014242 B CN103014242 B CN 103014242B
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Abstract
The invention relates to a stainless-steel smelting slagging agent and a smelting slagging method, in particular to a smelting slagging agent and a smelting slagging method adopting the AOD (Argon Oxygen Decarburization) double slag process, and belongs to the field of stainless-steel smelting. The smelting slagging agent adopting the AOD double slag process comprises a first ingredient and a second ingredient, wherein the first ingredient is waste (high alumina crushed brick) generated after cast steel pouring; the second ingredient is fluorite; high alumina crushed brick comprises the following materials by mass: 68 to 72 percent of Al2O3, 22 to 28 percent of SiO2, 2 to 5 percent of CaO and 2 to 5 percent of Fe2O3; and the mass ratio of the first ingredient to the second ingredient is 0.5 to 1. The smelting slagging agent adopting the AOD double slag process is low in cost, facilitates environmental protection, and is high in comprehensive slagging effect.
Description
Technical field
The present invention relates to a kind of stainless steel smelting dissolving agent and smelt slagging method, mainly relating to smelt dissolving agent and AOD double slag process smelting slagging method for AOD double slag process, belonging to stainless steel smelting field.
Background technology
Steelmaking process is used fluorite to make slag making dissolving agent more at present, because the main component CaF in fluorite
2can accelerate slag rapid melting, make thicker slag thinning, to increase flowing of slag, make it to be easy to desulfurization, but under the effect of high temperature and slag, CaF
2part part becomes volatile matter, and equipment, human body and environment are had to a large amount of injuries, and the AOD stove that especially stainless steel smelting is conventional, can be subject to CaF conventionally
2the phenomenon that corrodes furnace lining, cylinder-packing, for double slag process smelting technology, twice slag making makes CaF
2the phenomenon that corrodes furnace lining, cylinder-packing is even more serious; in addition; fluorite is as the main component of dissolving agent, and usage quantity is very high, and fluorite is because limited amount price is also more and more higher; therefore no matter from environmental protection or cost consideration; all, in the urgent need to the dissolving agent of Improvement type, patent publication No. is the Chinese patent of CN1027003639 (2012-10-03), discloses a kind of floride-free dissolving agent; the main component of this dissolving agent is bauxitic clay, although the method is not containing F
-, but for AOD double slag process smelting stainless steel, cost is still higher, and change slag effect not enough.
Summary of the invention
The object of the invention is to overcome the deficiency that prior art exists, provide a kind of AOD double slag process to smelt dissolving agent, described dissolving agent is comprised of the first component and second component; Described the first component is to water the useless brick of the waste high alumina producing after steel upper; Described second component is fluorite; The useless brick of described high alumina includes the component of following mass percent (%): Al
2o
368-72, SiO
222-28, CaO 2-5, Fe
2o
32-5; The quality ratio of described the first component and described second component is 0.5:1.It is low that this AOD double slag process is smelted dissolving agent cost, is beneficial to environmental protection and changes slag for comprehensive effective.
In order to improve stainless use properties, conventionally adopt AOD double slag process to smelt, produce low-phosphorus molten steel, and in AOD double slag process is smelted, the amount of AOD stove prereduction step use fluorite slag is generally 1 ton of steel of every refining and adds fluorite 20-28Kg, and the price of fluorite per ton is probably first at 2000-2500, therefore, cost is very high; The present invention adopts the useless brick of high alumina and fluorite to form dissolving agent and can greatly reduce costs, because the useless brick of high alumina waters the waste producing after steel upper in the present invention, main component is that massfraction is the Al of 68-72%
2o
3, the SiO of 22-28%
2, the CaO of 2-5% and the Fe of 2-5%
2o
3, also contain in addition a little impurity; Therefore general steelworks can, give up adding of brick by high alumina with the useless brick of this high alumina of the sell at competitive lower than 35 yuan/ton, and the cost of making slag reduces greatly.
In the present invention, the add-on of the useless brick of high alumina and fluorite is not only considered from fusing point, viscosity, basicity, the change slag ability aspect of slag, also to and cooperatively interact and determine with fluorite from the action effect of himself, the inventor through studying for a long period of time, just draw when AOD smelts described in the quality ratio of the first component and the described second component relation that is 0.5:1.
In the useless brick of high alumina, contain abundant Al
2o
3, after it joins in prereduction slag, can form CaO-SiO
2-Al
2o
3ternary slag system (or CaO-SiO
2-Al
2o
3-CaF
2quaternary slag system) substitute original CaO-SiO
2-CaF
2ternary slag system, to reach reduction slag melting point, the object of reaching slag reduction, can effectively adjust Al in prereduction slag because utilize high alumina brick to add
2o
3content, make CaO-Al
2o
3-SiO
2three component system slag is in low melting point position, in addition, and the viscosity (Pa.S) according to alkaline oxygenated slag 1600 ℃ time and the rough and ready formula of component relationship:
Lg η
1600 ℃=2.882+0.0455(Al
2o
3)-0.509(SiO
2)+1.17 (P
2o
5)-23.2 (S)-0.0122 (MnO)+0.0165 (FeO)-0.0322 (Fe
2o
3)-0.0201 (MgO)+0.0178 (CaO), by the calculating to this formula, controls Al
2o
3add-on so that control the add-on of the useless brick of high alumina so that cinder viscosity is controlled at 0.4 Pa.S left and right, more by reference to the accompanying drawings in 1 about CaO-Al
2o
3-SiO
2on the viscosity graph of a relation of slag system, can find out, viscosity minimum value is 0.3 Pa.S, and this region correspondence is at Al
2o
3content is 3%-8% left and right, and last, contriver is by CaO-Al
2o
3-SiO
2al in slag system
2o
3content be finally controlled at 3%-4.5%, this content can be in the situation that avoiding basicity to reduce as far as possible, maximum possible reduces cinder viscosity, increases the mobility of slag, meets the demand of smelting.
Al in the useless brick of high alumina for the present invention
2o
3content high quality mark is 68-72%, and Al
2o
3at about 950 ℃, can decomposes become γ-Al
2o
3, be the punctulate short texture of surperficial tool, to changing slag of great use, in addition, SiO in high alumina brick for the present invention
2content high quality mark is 22-28%, SiO
2also there is stronger change slag ability.
CaF in fluorite of the present invention
2can make that the fusing point of main component CaO in slag is minimum is down to 1360 ℃, Al in the useless brick of high alumina for the present invention
2o
3can make that the fusing point of main component CaO in slag is minimum is down to 1395 ℃, the inventor passes through the reasonable adjustment to the useless brick of high alumina and fluorite add-on when AOD smelts, not only can reduce slag melting, while also making AOD double slag process smelt, slag process costs reduces greatly, and the impact of environment, health and equipment is also reduced greatly.
As preferably, described AOD double slag process smelt in slag system include the component of following mass percent (%): CaO 61-65, SiO
231-35, Al
2o
33-5.In slag system, also has a small amount of impurity.
As preferably, the thickness of the useless brick of described high alumina is less than 10 centimetres.The present invention can be less than thickness the useless brick of high alumina of 10 centimetres and directly join in molten steel, without levigate, because high alumina brick is together to add with ferrosilicon, this period is the highest time period of temperature in AOD stove stove, and follow slag solid slag to the conversion of liquid slag, make Al2O3 can fully enter slag, the object of playing slag, and through the stirring of 6-7 minute, at high temperature, strong mixing, under chemical reaction triple role, the useless brick of block high alumina can melt completely, reaches brokenly lime, changes the effect of slag reduction.
As preferably, the thickness of the useless brick of described high alumina is less than 6 centimetres.
Another object of the present invention is to provide a kind of AOD double slag process and smelts slagging method, and described slagging method adopts the dissolving agent being comprised of the first component and second component; Described the first component is to water the useless brick of the waste high alumina producing after steel upper; Described second component is fluorite; The useless brick of described high alumina includes the component of following mass percent (%): Al
2o
368-72, SiO
222-28, CaO 2-5, Fe
2o
32-5; The quality ratio of described the first component and described second component is 0.4:1; Described dissolving agent is added in steel with Pre-reducing agent ferrosilicon in the prereduction process of AOD stove refining reduction, and basicity of slag in AOD stove is controlled as 2-4, cinder viscosity is controlled at 0.3-0.4, and churning time is controlled as 5-8 minute.
Basicity of the present invention refers to CaO and SiO in slag
2ratio, in the present invention, the control of basicity of slag and viscosity is all by the add-on of dissolving agent and joining day and the useless brick of high alumina and fluorite, to be interacted to coordinate to realize.
As preferably, when described AOD smelts, 1 ton of steel of every refining need to add the high alumina brick 6-13Kg that gives up.
As preferably, when described AOD smelts, 1 ton of steel of every refining need to add the high alumina brick 8-11Kg that gives up.
As preferably, when smelting, calculates respectively described AOD the add-on of the useless brick of high alumina and fluorite by the access times of AOD stove: when described access times are 0-20, when described AOD smelts, 1 ton of steel of every refining need to add the high alumina brick 9-11Kg that give up, and during described AOD smelting, 1 ton of steel of every refining need to add fluorite 5-7Kg; When described access times are 20-40, when described AOD smelts, 1 ton of steel of every refining need to add the high alumina brick 7-9Kg that give up, and during described AOD smelting, 1 ton of steel of every refining need to add fluorite 7-9Kg; When described access times are 40-60, when described AOD smelts, 1 ton of steel of every refining need to add the high alumina brick 5-7Kg that give up, and during described AOD smelting, 1 ton of steel of every refining need to add fluorite 9-11Kg.For the different AOD stove of access times, adjust respectively the add-on of the useless brick of high alumina and fluorite, can making slag better effects if.
The invention has the beneficial effects as follows:
1, AOD stove prereduction step of the present invention is used the amount of fluorite slag to be generally 1 ton of steel of every refining to add fluorite 20-28Kg, and the price of fluorite per ton is probably in 2000-2500 unit, and therefore, cost is very high; The present invention adopts the useless brick of high alumina and fluorite to form dissolving agent and can greatly reduce costs.
2, Al in the useless brick of high alumina for the present invention
2o
3content high quality mark is 68-72%, and Al
2o
3at about 950 ℃, can decomposes become γ-Al
2o
3, be the punctulate short texture of surperficial tool, to changing slag of great use, in addition, SiO in high alumina brick for the present invention
2content high quality mark is 22-28%, SiO
2also there is stronger change slag ability.
3, the CaF in fluorite of the present invention
2can make that the fusing point of main component CaO in slag is minimum is down to 1360 ℃, Al in the useless brick of high alumina for the present invention
2o
3can make that the fusing point of main component CaO in slag is minimum is down to 1395 ℃, the inventor passes through the reasonable adjustment to the useless brick of high alumina and fluorite add-on when AOD smelts, not only can reduce slag melting, while also making AOD double slag process smelt, slag process costs reduces greatly, and the impact of environment, health and equipment is also reduced greatly.
4, the present invention can be less than thickness the useless brick of high alumina of 10 centimetres and directly joins in molten steel, without levigate, because high alumina brick is together to add with ferrosilicon, this period is the highest time period of temperature in AOD stove stove, and follow slag solid slag to the conversion of liquid slag, make Al
2o
3can fully enter slag, the object of playing slag, and the process stirring of 6-7 minute, at high temperature, strong mixing, under chemical reaction triple role, the useless brick of block high alumina can melt completely, reaches brokenly lime, changes the effect of slag reduction.
5, the present invention adopts the useless brick of high alumina and fluorite to form dissolving agent, adopts AOD double slag process to smelt, and does not only reduce desulfurization, dephosphorization and deoxidation effect, can also greatly reduce costs, and is beneficial to environmental protection.
Accompanying drawing explanation
Fig. 1 is that the present invention smelts the CaO-Al of dissolving agent and AOD double slag process smelting slagging method for AOD double slag process
2o
3-SiO
2the viscosity figure of slag system.
Embodiment
This specific embodiment is only explanation of the invention; it is not limitation of the present invention; those skilled in the art can make to the present embodiment the modification that there is no creative contribution as required after reading this specification sheets, but as long as within the scope of claim of the present invention, are all subject to the protection of patent law.
Embodiment 1
AOD double slag process is smelted a dissolving agent, and it is that the useless brick of 10 centimetres of high aluminas and fluorite form by thickness, and the useless brick of high alumina by weight percentage (%) is comprised of following component: Al
2o
368-72, SiO
222-28, CaO 2-5, Fe
2o
32-5, all the other are impurity; Described AOD double slag process smelt in slag system by mass percentage the following component of (%) form: CaO 61-65, SiO
231-35, Al
2o
33-5, all the other are impurity; When AOD smelts, 1 ton of steel of every refining need to add the high alumina brick 6Kg that gives up; When described AOD smelts, 1 ton of steel of every refining need to add fluorite 6Kg; Described dissolving agent adds in steel with Pre-reducing agent ferrosilicon in the prereduction process of AOD stove refining reduction, and is 2 by basicity of slag control in AOD stove, and cinder viscosity is controlled at 0.3, and adding rear churning time is 5 minutes.
Embodiment 2
AOD double slag process is smelted a dissolving agent, and it is that the useless brick of 6 centimetres of high aluminas and fluorite form by thickness, and the useless brick of high alumina by weight percentage (%) is comprised of following component: Al
2o
368-72, SiO
222-28, CaO 2-5, Fe
2o
32-5, all the other are impurity; Described AOD double slag process smelt in slag system by mass percentage the following component of (%) form: CaO 61-65, SiO
231-35, Al
2o
33-5, all the other are impurity; When AOD smelts, 1 ton of steel of every refining need to add the high alumina brick 9Kg that gives up; When described AOD smelts, 1 ton of steel of every refining need to add fluorite 9Kg; Described dissolving agent adds in steel with Pre-reducing agent ferrosilicon in the prereduction process of AOD stove refining reduction, and is 3 by basicity of slag control in AOD stove, and cinder viscosity is controlled at 0.35, and adding rear churning time is 6 minutes.
Embodiment 3
AOD double slag process is smelted a dissolving agent, and it is that the useless brick of 4 centimetres of high aluminas and fluorite form by thickness, and the useless brick of high alumina by weight percentage (%) is comprised of following component: Al
2o
368-72, SiO
222-28, CaO 2-5, Fe
2o
32-5, all the other are impurity; Described AOD double slag process smelt in slag system by mass percentage the following component of (%) form: CaO 61-65, SiO
231-35, Al
2o
33-5, all the other are impurity; When AOD smelts, 1 ton of steel of every refining need to add the high alumina brick 11Kg that gives up; When described AOD smelts, 1 ton of steel of every refining need to add fluorite 11Kg; Described dissolving agent adds in steel with Pre-reducing agent ferrosilicon in the prereduction process of AOD stove refining reduction, and is 4 by basicity of slag control in AOD stove, and cinder viscosity is controlled at 0.4, and adding rear churning time is 8 minutes.
Claims (4)
1. AOD double slag process is smelted a dissolving agent, it is characterized in that: described dissolving agent is comprised of the first component and second component; Described the first component is to water the useless brick of the waste high alumina producing after steel upper; Described second component is fluorite; The useless brick of described high alumina includes the component of following mass percent (%): Al
2o
368-72, SiO
222-28, CaO 2-5, Fe
2o
32-5; The quality ratio of described the first component and described second component is 0.5:1.
2. a kind of AOD double slag process is smelted dissolving agent as claimed in claim 1, it is characterized in that: in described AOD double slag process smelting, slag system includes the component of following mass percent (%):
CaO?61-65，SiO
2?31-35，Al
2O
3?3-5。
3. a kind of AOD double slag process is smelted dissolving agent as claimed in claim 2, it is characterized in that: the thickness of the useless brick of described high alumina is less than 10 centimetres.
4. a kind of AOD double slag process is smelted dissolving agent as claimed in claim 3, it is characterized in that: the thickness of the useless brick of described high alumina is less than 6 centimetres.
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|---|---|---|---|
| CN201210548218.1A CN103014242B (en) | 2012-12-18 | 2012-12-18 | Smelting slagging agent and smelting slagging method adopting AOD (Argon Oxygen Decarburization) double slag process |
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| CN103014242B true CN103014242B (en) | 2014-04-02 |
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| CN107142359B (en) * | 2017-04-05 | 2019-02-19 | 邢台钢铁有限责任公司 | CaF in a kind of AOD finishing slag2The determination method of ratio |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1291657A (en) * | 1999-10-08 | 2001-04-18 | 鞍山钢铁集团公司 | Flux and process for forming slag of converter |
| CN1936029A (en) * | 2006-10-19 | 2007-03-28 | 唐山钢铁股份有限公司 | Method for utilizing waste steel ladle pouring material as converter slag-making fluxing agent |
| CN1962551A (en) * | 2006-11-24 | 2007-05-16 | 辽宁中兴矿业集团有限公司 | Manufacture of tundish nozzle pocket block filler using waste high-alumina brick and waste magnesium brick |
| CN101191170A (en) * | 2006-11-22 | 2008-06-04 | 宝山钢铁股份有限公司 | Method for smelting stainless steel oxidizing slag by using argon oxygen furnace |
| CN102344996A (en) * | 2010-08-06 | 2012-02-08 | 丹东泓辉科大高温材料有限公司 | Aluminium-silica type refined pre-smelting slag |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5531148A (en) * | 1978-08-28 | 1980-03-05 | Nippon Steel Corp | Manufacture of clean cast steel product |
| KR100889504B1 (en) * | 2002-12-23 | 2009-03-19 | 주식회사 포스코 | Fabrication method of stainless steel containing very low amount of carbon for heat resisting |
-
2012
- 2012-12-18 CN CN201210548218.1A patent/CN103014242B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1291657A (en) * | 1999-10-08 | 2001-04-18 | 鞍山钢铁集团公司 | Flux and process for forming slag of converter |
| CN1936029A (en) * | 2006-10-19 | 2007-03-28 | 唐山钢铁股份有限公司 | Method for utilizing waste steel ladle pouring material as converter slag-making fluxing agent |
| CN101191170A (en) * | 2006-11-22 | 2008-06-04 | 宝山钢铁股份有限公司 | Method for smelting stainless steel oxidizing slag by using argon oxygen furnace |
| CN1962551A (en) * | 2006-11-24 | 2007-05-16 | 辽宁中兴矿业集团有限公司 | Manufacture of tundish nozzle pocket block filler using waste high-alumina brick and waste magnesium brick |
| CN102344996A (en) * | 2010-08-06 | 2012-02-08 | 丹东泓辉科大高温材料有限公司 | Aluminium-silica type refined pre-smelting slag |
Non-Patent Citations (3)
| Title |
|---|
| JP昭55-31148A 1980.03.05 |
| 严敢.废耐火砖造还原渣脱硫实验及机理探讨.《炼钢》.1991,34-36. |
| 废耐火砖造还原渣脱硫实验及机理探讨;严敢;《炼钢》;19910228;34-36 * |
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Address after: 313005 Yongxing special stainless steel Limited by Share Ltd, Zhejiang Industrial Development Zone, Huzhou Economic Development Zone Patentee after: Yongxing special material technology Co., Ltd Address before: 313005 Yongxing special stainless steel Limited by Share Ltd, Zhejiang Industrial Development Zone, Huzhou Economic Development Zone Patentee before: Yongxing Special Stainless Steel Co., Ltd. |
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