WO1993017131A1 - Verfahren zur entschwefelung von eisenschmelzen bei minimalem schlacke-anfall und eine dafür geeignete vorrichtung - Google Patents
Verfahren zur entschwefelung von eisenschmelzen bei minimalem schlacke-anfall und eine dafür geeignete vorrichtung Download PDFInfo
- Publication number
- WO1993017131A1 WO1993017131A1 PCT/DE1993/000165 DE9300165W WO9317131A1 WO 1993017131 A1 WO1993017131 A1 WO 1993017131A1 DE 9300165 W DE9300165 W DE 9300165W WO 9317131 A1 WO9317131 A1 WO 9317131A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- slag
- weight
- iron
- desulfurization
- furnace
- Prior art date
Links
Classifications
-
- 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
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/02—Dephosphorising or desulfurising
-
- 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
Definitions
- the invention relates to a process for the desulfurization of molten iron with minimal slag accumulation and a device suitable therefor.
- Pig iron as it comes from the blast furnace, usually contains 0.03% - 0.08% sulfur. It is state of the art to reduce the sulfur content of the pig iron before further processing in the steel plant, depending on the intended use of the steel produced, by means of various desulfurization processes to contents of less than 0.01% or less than 0.005%.
- Unreacted carbide can also be present in the desulfurization slags that are used, which releases toxic and explosive acytylene gas when exposed to water.
- the object of the invention was to provide a method for desulfurizing iron melts which avoids the disadvantages mentioned, and to provide an apparatus for carrying out the method.
- a process for the desulphurization of molten iron has been found, which can be used for pig iron as well as cast iron, and which does not have the serious disadvantages of the usual desulphurization processes for molten iron, since almost no sulfur-containing slag is produced from the outset and this can also be desulphurized.
- Another advantage of the process according to the invention is that there is also no need for expensive processing of a high iron-containing slag.
- the process according to the invention can do without the expensive desulphurization agents based on carbide or magnesium, which makes it considerably cheaper than the processes currently used which correspond to the prior art.
- the pig iron is not desulfurized in the torpedo pan or charging pan of the steelworks, as is customary, but instead it is e.g. a specially developed downhole furnace electrically heated by means of graphite or coal electrodes or a correspondingly adapted ladle furnace or electric furnace was used. Resistance heating in this furnace melts such large quantities of basic slag that a weight ratio of iron melt to slag of less than 10, preferably less than 5, and particularly preferably less than 2.5 in the case of continuous desulfurization, is maintained in the desulfurization process.
- the downhole furnace according to the invention can be tilted and has a pouring device which allows the desulfurized iron melt to be drawn off under the desulfurization slag. This is preferably achieved by means of a pouring pipe, which extends down to the bottom of the working space of the furnace. Opposite the pouring pipe there is an inlet channel for the pig iron to be desulfurized. On Bo 'to the furnace boiler below the intake chute for the pig iron can be mounted a nozzle or a porous plug. However, several nozzles or flushing stones can also be placed on the bottom or on the side walls of the invention. downhole furnace according to the invention.
- the furnace is expediently lined with crushed coal, charcoal stones or, in particular, on the furnace floor and wherever predominantly liquid iron comes into contact with the lining with carbon-containing, basic or high-alumina refractory stones.
- melting units can also be used for the process according to the invention.
- the prerequisite for this is that there is the possibility of melting slag by means of electrodes and pouring the iron either continuously or discontinuously separately from the slag.
- Melting units which can be used for the methods according to the invention after appropriate adaptation are ladle furnaces or e.g. Electric furnace with an eccentric bottom cut.
- the refractory lining described is also expedient for ladle ovens or electric ovens which have been adapted for the method according to the invention.
- the desulfurization process can be carried out by first melting a basic slag in the furnace and then pouring in the sulfur-rich pig iron.
- the reverse order, especially when using a pan oven, is also possible and useful.
- the chemical analysis of the slag used is as follows:
- the preferred composition of the slag has the following chemical analysis:
- composition of the slag according to the invention has the following chemical composition:
- the electrodes are immersed in the liquid slag, which is then heated by resistance heating. The remaining quantities of the required slag are dissolved in the slag bath thus formed.
- the liquid slag is brought to a temperature of 1400-1800 ° C, preferably 1500-1700 ° C, particularly preferably 1550-1650 ° C.
- the sulfur-containing iron melt is then allowed to flow evenly into this hot slag.
- the iron melt is desulfurized very quickly.
- the desulfurization reaction takes place particularly quickly when, for example, a gas consisting of argon, nitrogen or air or mixtures of these gases is blown through a sink or one or more floor nozzles, as a result of which hot slag is flushed against the inflowing iron melt.
- an iron melt which has already settled on the furnace floor, is stirred vigorously. It can give off the remaining sulfur to the hot slag.
- the reaction of the iron melt with the slag can be intensified by a funnel in the inlet which is covered by the liquid slag and into which the sulfur-containing iron melt runs. To do this, hot slag is pumped up through the funnel using a gas jet. The hot slag is swirled with the incoming molten iron. It transports the molten iron out of the funnel at the top.
- Gases such as air and / or water vapor can also be blown into the slag melt or through the slag melt into the iron melt by means of one or more lances immersed in the slag melt from above, thereby accelerating the desulfurization process.
- the usual desulfurization agents for pig iron for example based on carbide or lime, can also be blown in with the gas through the floor nozzle.
- Such a measure can be expedient, for example, if an iron melt with a particularly high sulfur content and / or to an extremely low final content has to be desulfurized in the shortest possible time.
- blowing in a small amount of the desulfurizing agent can also be useful. This is especially true when some blast furnace slag runs with the pig iron in the downhole furnace.
- a mode of operation is also possible in which the pig iron is poured into the downhole furnace and the desulphurization takes place at the same time. Then desulphurization is carried out and then the pig iron is poured out by tilting the low shaft furnace. If the pouring hole has become blocked, it must be burned up by means of an electrode, for example.
- the use of a correspondingly adapted ladle furnace or electric furnace is also possible for the method according to the invention.
- the ladle When using a ladle furnace, the ladle is first filled with pig iron rich in sulfur, and then with the help of electrodes, such a quantity of liquid slag is smelted on the raw iron that the weight ratio of iron to slag does not fall below 10 to 1. Even during the melting of the slag until the end of the desulfurization process, the pig iron is stirred by blowing gases through one or more sink stones at the bottom of the pan.
- the slag After the slag has melted, it is blown into the melt by means of one or more water-cooled lan air or air and water or water vapor immersed in the slag.
- the desulphurized pig iron is then poured out through a slide located on the bottom of the pan. Fresh, sulfur-rich pig iron is then poured into the pan and the next batch is desulphurized.
- the slag is usually exhausted when its sulfur content has exceeded about 6-8% by weight.
- 750 t to 1000 t of pig iron can be desulfurized from an initial sulfur content of 0.05% to a final sulfur content of 0.01% with a low-chimney furnace containing 5 t of desulphurization slag.
- a blast furnace that produces 10,000 t of pig iron per day, this is the case after approx. 1 1/2 to 2 1/2 hours.
- a sulfur breakdown of approximately 1% by weight per hour can be achieved in the slag.
- a downhole furnace according to the invention which contains 20 t of slag with a composition according to the invention, about 500 t of pig iron per hour can be desulfurized from 0.05 to 0.01% for days.
- a slag with a high sulfur content which is treated with an oxidizing agent, not only loses its ability to desulphurize, but on the contrary has a sulfurizing effect on molten iron with a low sulfur content.
- the slag loses part of its sulfur content.
- the slag When the desulfurization slag has been saturated with sulfur, i.e. if the desired level of desulfurization is no longer achieved, the slag can be subjected to a regeneration process. For this purpose, the pig iron inflow is first stopped and the pig iron is poured out completely.
- the subsequent regeneration of the slag is carried out by oxidation, if appropriate after adding SiO 2 and / or A1 2 O 3 .
- the slag can be oxidized by blowing in air and / or oxygen or by adding an oxidizing agent such as iron oxide, iron ore and / or manganese ore.
- the sulfur content of the oxidized melt can be reduced, for example, from 6% to below 0.20% within a few minutes.
- a reducing agent for example coal, coke, lignite coke, peat coke or charcoal
- reducing agent for example coal, coke, lignite coke, peat coke or charcoal
- Other reducing agents such as Aluminum can be used to reduce the slag's heavy metal oxides.
- the desulfurization process for pig iron can be started again.
- the oxidation process produces S0, which can be converted to gypsum, for example, in a conventional scrubber by reacting with hydrated lime in the flue gas of the furnace. This gypsum from the conversion of the flue gases with lime can easily be processed or deposited.
- the method according to the invention is therefore very environmentally friendly.
- only a fraction of the desulfurization slag used is obtained, and even this can be processed into high-quality, sulfur-free desulfurization slag.
- small amounts of gypsum are produced, which can be landfilled or processed without any problems.
- a small amount of slag is unavoidable because the pig iron containing sulfur cannot be separated quantitatively from the blast furnace slag that is running along before the desulfurization process.
- small amounts especially of lime, fluorspar and possibly alumina, must be added to the desulfurization slag according to the amount and chemical analysis of the blast furnace slag.
- Another advantage of the process according to the invention is that the pig iron is heated up during the desulfurization process.
- the downhole furnace according to the invention can even be used for the additional melting and desulfurization of scrap iron. This can e.g. proceed in such a way that a certain amount of cut iron scrap is continuously charged in the furnace according to the invention.
- An advantage of the desulphurization process according to the invention that cannot be overlooked is that the described low shaft furnace can be inserted between the blast furnace and converter at various points in the production process without any problems, since, due to its special design principle, between the inlet channel for the sulfur-containing and the pouring hole for the desulfurized pig iron requires very little height.
- the downhole furnace is electrically heated by means of graphite electrodes 1. It is tiltable and has a pouring spout 2 which extends to the bottom of the working space of the furnace.
- the pouring pipe enables the desulfurized iron melt 3 to be drawn off under the desulfurization slag 4. Opposite the pouring pipe there is an inlet channel 5 for the pig iron to be desulfurized. At the bottom of the Ofenkess ⁇ lr-, below the gutter for the pig iron, there is a Du. ? 6 attached.
- a test furnace with an elliptical furnace boiler was used, which was lined with crushed coal and a capacity of 400 mm in length, 260 mm in width and 240 mm deep.
- the furnace On the pouring side, the furnace had a graphite tube with 100 mm outer diameter and 30 mm inner diameter, which reached down to the bottom of the melting chamber. 20 kg of desulfurization slag were melted in this vessel with the aid of 2 electrodes with a diameter of 100 mm.
- the slag and cast iron were kept at temperature for half an hour.
- either slag and melt were stirred with a graphite rod for 5 minutes at the end of the half-hour test time (Examples 1 and 4) or air or air plus water vapor was blown into the slag during the half hour melting time (Examples 2 and 3).
- the blowing rate of the gases was chosen so that the slag was agitated vigorously, but without large quantities of slag spraying out of the test furnace.
- the desulfurized cast iron was then poured off through the graphite tube.
- the cast iron used for the tests contained 0.21% by weight of S, 3.17% by weight of C, 2.06% by weight of Si and 0.27% by weight of Mn.
- the test results are summarized in Table 1 at the end of the description.
- the calculated sulfur contents of the slags (S calculated) are also given.
- the calculated sulfur contents of the slags result from the initial content of the respective slags, i.e. from the sulfur content found in the previous test plus the calculated increase in the S content from the desulfurization of the cast iron during the test.
- Sample No. 0 indicates the S content of the cast iron used.
- the sulfur values of the desulfurized cast iron were between 0.010 and 0.017% by weight (Pr.No. 1-3).
- the calculated sulfur losses of the slags were 0.38% by weight based on the test period of half an hour.
- the S content of the slag could be reduced to 0.13% by weight by adding 40% manganese ore. (Pr.No. 5).
- Example 3 compressed air and water vapor were blown into the slag using a lance.
- the sulfur content of the desulfurized cast iron was between 0.002 and 0.003% by weight (Pr.No. 1-3).
- the calculated S losses of the slags fluctuated between 0.49 and 0.56% by weight (Pr No. 2-3) based on the test duration of half an hour.
- the slag temperature was 1530 ° C.
- the desulfurization effect of the slag was not satisfactory.
- the S content of the cast iron after the desulfurization process was between 0.044 and 0.059% by weight. (Pr No. 1-4)
- the slag temperature was 1630 ° C.
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE59307023T DE59307023D1 (de) | 1992-02-27 | 1993-02-25 | Verfahren zur entschwefelung von eisenschmelzen bei minimalem schlacke-anfall und eine dafür geeignete vorrichtung |
KR1019940703002A KR100269897B1 (ko) | 1992-02-27 | 1993-02-25 | 최소의 슬래그형성물을 가지고 철용해물을 탈황시키기 위한 방법 및 그 방법을 수행하기 위한 장치 |
JP51445593A JP3902223B2 (ja) | 1992-02-27 | 1993-02-25 | スラグ生成を最少にして溶融鉄を脱硫する方法と,それを実施する装置 |
EP93903828A EP0627012B1 (de) | 1992-02-27 | 1993-02-25 | Verfahren zur entschwefelung von eisenschmelzen bei minimalem schlacke-anfall und eine dafür geeignete vorrichtung |
US08/295,733 US5466275A (en) | 1992-02-27 | 1993-02-25 | Method and apparatus for desulphurizing iron with minimal slag formation |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DEP4206091.5 | 1992-02-27 | ||
DE4206091A DE4206091C2 (de) | 1992-02-27 | 1992-02-27 | Verfahren zur Entschwefelung von Eisenschmelzen bei minimalem Schlacke-Anfall und eine dafür geeignete Vorrichtung |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1993017131A1 true WO1993017131A1 (de) | 1993-09-02 |
Family
ID=6452754
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/DE1993/000165 WO1993017131A1 (de) | 1992-02-27 | 1993-02-25 | Verfahren zur entschwefelung von eisenschmelzen bei minimalem schlacke-anfall und eine dafür geeignete vorrichtung |
Country Status (8)
Country | Link |
---|---|
US (1) | US5466275A (de) |
EP (1) | EP0627012B1 (de) |
JP (1) | JP3902223B2 (de) |
KR (1) | KR100269897B1 (de) |
AT (1) | ATE156196T1 (de) |
CA (1) | CA2130996A1 (de) |
DE (2) | DE4206091C2 (de) |
WO (1) | WO1993017131A1 (de) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1999060173A1 (de) * | 1998-05-20 | 1999-11-25 | Voest-Alpine Industrieanlagenbau Gmbh | Verfahren zum integrierten entschwefeln von roheisen- und stahlschmelzen |
Families Citing this family (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19546738C2 (de) * | 1995-12-14 | 1997-12-18 | Eko Stahl Gmbh | Verfahren zur Entschwefelung von Roheisenschmelzen |
DE19609606A1 (de) * | 1996-03-12 | 1997-09-18 | Dillinger Huettenwerke Ag | Verfahren zum Entschwefeln von Roheisen |
AT409141B (de) * | 2000-09-12 | 2002-05-27 | Voest Alpine Ind Anlagen | Verfahren und vorichtung zur entschwefelung von roheisen |
US20050056120A1 (en) * | 2003-09-15 | 2005-03-17 | Flores-Morales Jose Ignacio | Desulphurization of ferrous materials using sodium silicate |
US20050066772A1 (en) * | 2003-09-26 | 2005-03-31 | Flores-Morales Jose Ignacio | Desulphurization of ferrous materials using glass cullet |
US7950841B2 (en) | 2005-02-23 | 2011-05-31 | Air Liquide Industrial U.S. Lp | Concrete cooling injection unit and method of injecting a coolant into a concrete mixture |
FI122348B (fi) | 2008-05-30 | 2011-12-15 | Rautaruukki Oyj | Menetelmä kalsiumkarbonaatin tuottamiseksi jäte- ja sivutuotteista |
DE102013113197A1 (de) | 2013-11-28 | 2015-05-28 | Voestalpine Stahl Gmbh | Verfahren zum Bearbeiten von Entschwefelungsschlacke |
JP6263144B2 (ja) * | 2015-03-23 | 2018-01-17 | 日新製鋼株式会社 | 製鋼スラグからカルシウムを含有する固体成分を回収する方法、および回収された固体成分 |
RU2588915C1 (ru) * | 2015-03-23 | 2016-07-10 | Общество С Ограниченной Ответственностью Ооо "Экос" | Способ десульфурации чугуна |
CN105021776B (zh) * | 2015-07-28 | 2017-06-27 | 西安交通大学 | 一种生物质锅炉硅酸盐结渣趋势的判定方法 |
DE102016002419A1 (de) * | 2015-11-19 | 2017-05-24 | Sms Group Gmbh | Verfahren und Vorrichtung zum Reinigen von Schlacke |
CN107447156B (zh) * | 2017-08-01 | 2019-06-04 | 江油市长祥特殊钢制造有限公司 | 热作模具钢及其生产方法 |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2246615A1 (de) * | 1972-09-22 | 1974-03-28 | Thermo Ind Gmbh & Co Kg | Verfahren und vorrichtung zur entschwefelung von roheisen |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3802865A (en) * | 1969-08-29 | 1974-04-09 | Nippon Kokan Kk | Self soluble slag forming agents for use in steel making |
CA1060214A (en) * | 1974-02-27 | 1979-08-14 | Masaru Takashima | Method for desulfurizing molten iron |
JPS5159714A (en) * | 1974-11-21 | 1976-05-25 | Nippon Steel Corp | Yosenno datsuryuzai |
JPS609565B2 (ja) * | 1978-02-27 | 1985-03-11 | トヨタ自動車株式会社 | 溶融スラグによる鋳鉄溶湯の精錬方法 |
DE3331046A1 (de) * | 1983-08-29 | 1985-03-14 | Wacker-Chemie GmbH, 8000 München | Verfahren zum behandeln von silicium und ferrosilicium mit schlacke |
DE3535280A1 (de) * | 1985-10-03 | 1987-04-09 | Hoechst Ag | Entschwefelungsgemisch fuer metallschmelzen, ein verfahren zu seiner herstellung und seine verwendung |
DE3837249A1 (de) * | 1988-10-31 | 1990-05-03 | Salzgitter Peine Stahlwerke | Verfahren zur aufbereitung von schlacken metallurgischer prozesse unter rueckgewinnung von soda |
-
1992
- 1992-02-27 DE DE4206091A patent/DE4206091C2/de not_active Expired - Fee Related
-
1993
- 1993-02-25 WO PCT/DE1993/000165 patent/WO1993017131A1/de active IP Right Grant
- 1993-02-25 JP JP51445593A patent/JP3902223B2/ja not_active Expired - Fee Related
- 1993-02-25 CA CA002130996A patent/CA2130996A1/en not_active Abandoned
- 1993-02-25 DE DE59307023T patent/DE59307023D1/de not_active Expired - Fee Related
- 1993-02-25 US US08/295,733 patent/US5466275A/en not_active Expired - Lifetime
- 1993-02-25 EP EP93903828A patent/EP0627012B1/de not_active Expired - Lifetime
- 1993-02-25 KR KR1019940703002A patent/KR100269897B1/ko not_active IP Right Cessation
- 1993-02-25 AT AT93903828T patent/ATE156196T1/de not_active IP Right Cessation
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2246615A1 (de) * | 1972-09-22 | 1974-03-28 | Thermo Ind Gmbh & Co Kg | Verfahren und vorrichtung zur entschwefelung von roheisen |
Non-Patent Citations (3)
Title |
---|
Derwent Publications Ltd., London, GB; AN 76-52764XC28 * |
METALS Bd. 2, Nr. 20, Januar 1968, LONDON Seite 51 'slag refining of cast iron' * |
PATENT ABSTRACTS OF JAPAN vol. 3, no. 133 (C-63)(152) 7. November 1979 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1999060173A1 (de) * | 1998-05-20 | 1999-11-25 | Voest-Alpine Industrieanlagenbau Gmbh | Verfahren zum integrierten entschwefeln von roheisen- und stahlschmelzen |
US6506225B1 (en) | 1998-05-20 | 2003-01-14 | Voest-Alpine Industrieanlagenbau Gmbh | Method for integrated desulfurizing of pig iron melt and steel melt |
KR100581468B1 (ko) * | 1998-05-20 | 2006-05-23 | 뵈스트-알핀 인두스트리안라겐바우 게엠베하 | 선철 및 용강의 통합 탈황 방법 |
Also Published As
Publication number | Publication date |
---|---|
US5466275A (en) | 1995-11-14 |
CA2130996A1 (en) | 1993-08-28 |
KR100269897B1 (ko) | 2000-10-16 |
DE59307023D1 (de) | 1997-09-04 |
ATE156196T1 (de) | 1997-08-15 |
EP0627012A1 (de) | 1994-12-07 |
KR950700427A (ko) | 1995-01-16 |
DE4206091A1 (de) | 1993-09-02 |
DE4206091C2 (de) | 1994-09-22 |
EP0627012B1 (de) | 1997-07-30 |
JPH07504230A (ja) | 1995-05-11 |
JP3902223B2 (ja) | 2007-04-04 |
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