EP0220522B1 - Mixture for desulfurizing metal melts, process for manufacturing it and its use - Google Patents

Mixture for desulfurizing metal melts, process for manufacturing it and its use Download PDF

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Publication number
EP0220522B1
EP0220522B1 EP86113501A EP86113501A EP0220522B1 EP 0220522 B1 EP0220522 B1 EP 0220522B1 EP 86113501 A EP86113501 A EP 86113501A EP 86113501 A EP86113501 A EP 86113501A EP 0220522 B1 EP0220522 B1 EP 0220522B1
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weight
mixture
percent
desulfurization
calcium
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EP86113501A
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German (de)
French (fr)
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EP0220522A1 (en
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Hermann Dr. Schrödter
Albert Braun
Friedrich-Wilhelm Dr. Kampmann
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Hoechst AG
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Hoechst AG
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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
    • C21C1/00—Refining of pig-iron; Cast iron
    • C21C1/02—Dephosphorising or desulfurising
    • C21C1/025—Agents used for dephosphorising or desulfurising

Definitions

  • the present invention relates to a method for producing a desulfurization mixture for molten metals based on calcium carbide.
  • DE-PS 20 37 758 describes a special calcium carbide in which a mixture of quicklime and fluorspar is introduced into the calcium carbide melt and then the solidified calcium carbide is crushed.
  • the disadvantage of this process was that only about 2/3 of the fluorine used remained in the melt.
  • DE-PS-26 42 838 describes a process for desulfurizing steel, in which a mixture of calcium carbide with 5 to 25 percent by weight calcium fluoride is added to the metal melt under reduced pressure. It has been shown that this mixture is not suitable for dosing via a submersible lance, since caking occurs in the lance during the blowing process. In addition, slag incrustations form on the pan walls. This desulfurization mixture can be used successfully if there is no slag on the metal bath at first.
  • EP-A-61 011 describes a process for the production of desulfurization agents for pig iron or steel melts, in which a calcium carbide-calcium oxide melt mixture is ground together with free carbon and carbonate in the presence of moist air or nitrogen. With this desulfurization mixture, the desulfurization reaction is started very early and evenly, and a more targeted desulfurization result is made possible with lower application quantities.
  • the object of the present invention is to provide a method for producing a desulfurization mixture with a high degree of desulfurization, which can be produced without the formation of fluoride-containing exhaust gases and which, when used, develops only low fluoride-containing emissions and forms a crumbly slag layer.
  • the content of pure CaC 2 in the carbide furnace is set, or the content of pure CaC 2 in the liquid phase in the crucible is adjusted by lean with quicklime or the content of pure CaC 2 in the carbide furnace is rough adjusted and then finally adjusted in the liquid phase in the crucible by adding quicklime.
  • the desulfurization mixture according to the invention can contain up to 30 percent by weight of alkali carbonate, preferably in the form of anhydrous soda.
  • the grinding process in particular the grinding time, is of great importance for the production of an optimal mixture with regard to flowability and desulfurization.
  • the desulfurization mixture does not cause caking, neither in the lance nor in its feed pipes. It has also been shown that when the desulfurization mixture is used, there is no slag encrustation on the metal pan wall. The emission of undesired fluoride emissions during the desulfurization process is significantly lower compared to a calcium carbide / calcium fluoride mixture produced in the usual ways.
  • the sulfur content was reduced from 0.024 to 0.0025 percent S.
  • the sulfur content was reduced from 0.025 to 0.0007 percent S.

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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)
  • Treatment Of Steel In Its Molten State (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)
  • Manufacture And Refinement Of Metals (AREA)

Abstract

Mixture for desulfurizing metal melts based on calcium carbide, calcium oxide, alkaline earth metal carbonates, aluminum oxide, chemically unbonded carbon and alkali metal carbonates, if any. The desulfurizing mixture contains 0.3-4.5 wgt % calcium fluoride as an additional constituent and is produced by grinding the individual constituents jointly in a mill over a period of 3-30 minutes.

Description

Vorliegende erfindung betrifft ein Verfahren zur Herstellung eines Entschwefelungsgemisches für Metallschmelzen auf der Basis von Calciumcarbid.The present invention relates to a method for producing a desulfurization mixture for molten metals based on calcium carbide.

Durch die Verarbeitung von minderwertigen Eisenerzen sowie Schrott im Konverter und durch den steigenden Einsatz von höher schwefelhaltigem Koks bzw. Ölkoks gewinnt die Entschwefelung von Roheisen zunehmend an Bedeutung. Nur durch die Entschwefelung der Eisenschmelze können die heute in zunehmenden Mengen verarbeiteten hochwertigen schwefelarmen Stähle zur Verfügung gestellt werden.The processing of low-quality iron ores and scrap in the converter and the increasing use of high-sulfur coke and oil coke mean that the desulfurization of pig iron is becoming increasingly important. Only through the desulphurization of the molten iron can the high-quality, low-sulfur steels processed today in increasing quantities be made available.

In der Technik hat es deshalb nicht an Versuchen gefehlt, wirksame Entschwefelungsmittel bereitzustellen. Von einer reinen Kalkentschwefelung kam man bald ab, da diese Entschwefelung eine FeO-arme Schlacke verlangt und ein heißes Schmelzen erforderlich macht, wodurch eine gesteigerte unerwünschte Silizium-Reduktion eintritt. Durch die Zugabe von Calciumcarbid, insbesondere wenn das Calciumcarbid mit Calciumoxid gemagert ist, konnte die Behandlungstemperatur der Metallschmelze abgesenkt werden.There has been no shortage of attempts in the art to provide effective desulfurization agents. Pure desulphurization was soon abandoned, since this desulphurization requires a low-FeO slag and requires hot melting, which leads to an increased undesirable silicon reduction. The treatment temperature of the molten metal could be reduced by adding calcium carbide, especially if the calcium carbide is leaned with calcium oxide.

In der DE-PS 20 37 758 wird ein spezielles Calciumcarbid beschrieben, bei dem in die Calciumcarbidschmelze ein Gemisch aus gebranntem Kalk und Flußspat eingetragen wird und anschließend das erstarrte Calciumcarbid zerkleinert wird. Nachteilig bei diesem Verfahren war, daß nur etwa 2/3 des eingesetzten Fluors in der Schmelze verblieb.DE-PS 20 37 758 describes a special calcium carbide in which a mixture of quicklime and fluorspar is introduced into the calcium carbide melt and then the solidified calcium carbide is crushed. The disadvantage of this process was that only about 2/3 of the fluorine used remained in the melt.

In der DE-PS-26 42 838 wird ein Verfahren zum Entschwefeln von Stahl beschrieben, bei dem ein Gemisch aus Calciumcarbid mit 5 bis 25 Gewichtsprozent Calciumfluorid der Metallschmelze unter Unterdruck zugesetzt wird. Es hat sich gezeigt, daß dieses Gemisch nicht zur Dosierung über eine Tauchlanze geeignet ist, da es bei dem Blasvorgang zu Anbackungen in der Lanze kommt. Außerdem bilden sich Schlackenverkrustungen an den Pfannenwänden. Dieses Entschwefelungsgemisch kann dann mit Erfolg angewandt werden, wenn anfangs keine Schlacke auf dem Metallbad ist.DE-PS-26 42 838 describes a process for desulfurizing steel, in which a mixture of calcium carbide with 5 to 25 percent by weight calcium fluoride is added to the metal melt under reduced pressure. It has been shown that this mixture is not suitable for dosing via a submersible lance, since caking occurs in the lance during the blowing process. In addition, slag incrustations form on the pan walls. This desulfurization mixture can be used successfully if there is no slag on the metal bath at first.

In der EP-A-61 011 wird ein Verfahren zur Herstellung von Entschwefelungsmitteln für Roheisen-oder Stahlschmelzen beschrieben, bei welchem ein Calciumcarbid-Calciumoxid-Schmelzgemisch zusammen mit freiem Kohlenstoff und Carbonat in Gegenwart von feuchter Luft oder Stickstoff aufgemahlen wird. Mit diesem Entschwefelungsgemisch wird die Entschwefelungsreaktion sehr früh und gleichmäßig in Gang gesetzt und mit geringeren Anwendungsmengen ein gezielteres Entschwefelungsergebnis ermöglicht.EP-A-61 011 describes a process for the production of desulfurization agents for pig iron or steel melts, in which a calcium carbide-calcium oxide melt mixture is ground together with free carbon and carbonate in the presence of moist air or nitrogen. With this desulfurization mixture, the desulfurization reaction is started very early and evenly, and a more targeted desulfurization result is made possible with lower application quantities.

Aufgabe der vorliegenden Erfindung ist es, ein Verfahren zur Herstellung eines Entschwefelungsgemisches mit hohem Entschwefelungsgrad anzugeben, welches ohne die Bildung von fluoridhaltigen Abgasen hergestellt werden kann und das bei seiner Anwendung nur niedrige fluoridhaltige Emissionen entwickelt und eine krümelige Schlackenschicht bildet.The object of the present invention is to provide a method for producing a desulfurization mixture with a high degree of desulfurization, which can be produced without the formation of fluoride-containing exhaust gases and which, when used, develops only low fluoride-containing emissions and forms a crumbly slag layer.

Überraschenderweise hat sich nun gezeigt, daß die Aufgabe dadurch gelöst werden kann, daß man ein Gemisch bestehend aus

  • 32 bis 89 Gewichtsprozent Calciumcarbid
  • 5 bis 66 Gewichtsprozent Calciumoxid
  • 0,1 bis 45 Gewichtsprozent Erdalkalicarbonat
  • 0,1 bis 10 Gewichtsprozent Aluminiumoxid
  • 0,1 bis 10 Gewichtsprozent chemisch nicht gebundenem Kohlenstoff
  • 0,3 bis 4,5 Gewichtsprozent Calciumfluorid

in einer Körnung von 0,1 bis 50 mm, vorzugsweise 0,2 bis 20 mm, als homogene Mischung durch einen Mahlvorgang unter trockener Inertgasatmosphäre in einer Mühle auf eine Größe von < 0,5 mm aufmahlt und das Mahlgut 3 bis 30, vorzugsweise 10 bis 20 Minuten in einer Mühle mahlt.Surprisingly, it has now been shown that the object can be achieved in that a mixture consisting of
  • 32 to 89 weight percent calcium carbide
  • 5 to 66 weight percent calcium oxide
  • 0.1 to 45 weight percent alkaline earth carbonate
  • 0.1 to 10 weight percent aluminum oxide
  • 0.1 to 10 percent by weight of chemically unbound carbon
  • 0.3 to 4.5 weight percent calcium fluoride

in a grain size of 0.1 to 50 mm, preferably 0.2 to 20 mm, as a homogeneous mixture by grinding in a dry inert gas atmosphere in a mill to a size of <0.5 mm and the ground material 3 to 30, preferably 10 grinds in a mill for up to 20 minutes.

Das Verfahren der Erfindung kann weiterhin wahlweise auch noch dadurch ausgestaltet sein, daß man

  • 1) 0,25 bis 1,7 Gewichtsprozent Fluor, vorzugsweise als Flußspat, einbringt;
  • 2) ein technisches Carbid mit einem CaC2-Gehalt von 20 bis 80 Gewichtsprozent einsetzt ;
  • 3) als Erdalkalicarbonat Kalkstein und/oder Dolomit einbringt ;
  • 4) bis zu 30 Gewichtsprozent Alkalicarbonat, vorzugsweise wasserfreie Soda, einbringt ;
  • 5) als Inertgas Stickstoff verwendet ;
  • 6) durch den Mahlvorgang mindestens 85 Gewichtsprozent des Endproduktes auf eine Korngröße von < 0,1 mm aufmahlt, da dann dieses Entschwefelungsgemisch problemlos in das flüssige Metall in einer Menge von 0,5 bis 5,0 kg/t Metall über eine Tauchlanze mit einem Trägergas eingeblasen werden kann.
The method of the invention can furthermore optionally also be designed in that
  • 1) 0.25 to 1.7 weight percent fluorine, preferably as fluorspar;
  • 2) uses a technical carbide with a CaC 2 content of 20 to 80 percent by weight;
  • 3) introduces limestone and / or dolomite as alkaline earth carbonate;
  • 4) introduces up to 30 weight percent alkali carbonate, preferably anhydrous soda;
  • 5) nitrogen is used as the inert gas;
  • 6) through the grinding process, at least 85 percent by weight of the end product is ground to a grain size of <0.1 mm, since this desulfurization mixture can then be easily introduced into the liquid metal in an amount of 0.5 to 5.0 kg / t metal using a submersible lance Carrier gas can be blown.

Hierbei spielt es keine Rolle, ob ein technisches Calciumcarbid verwendet wird, dessen Gehalt an reinem CaC2 im Carbidofen eingestellt oder dessen Gehalt an reinem CaC2 in der flüssigen Phase im Tiegel durch Magern mit Branntkalk eingestellt oder dessen Gehalt an reinem CaC2 im Carbidofen grob eingestellt und danach in der flüssigen Phase im Tiegel durch Zugabe von Branntkalk endgültig eingestellt wurde.It does not matter whether a technical calcium carbide is used, the content of pure CaC 2 in the carbide furnace is set, or the content of pure CaC 2 in the liquid phase in the crucible is adjusted by lean with quicklime or the content of pure CaC 2 in the carbide furnace is rough adjusted and then finally adjusted in the liquid phase in the crucible by adding quicklime.

Für die Herstellung des Entschwefelungsgemisches kann als Erdalkalicarbonat Kalkstein und/oder Dolomit verwendet werden. Schließlich kann das erfindungsgemäße Entschwefelungsgemisch bis zu 30 Gewichtsprozent Alkalikarbonat, vorzugsweise in Form wasserfreier Soda, enthalten.Limestone and / or dolomite can be used as the alkaline earth carbonate to produce the desulfurization mixture. Finally, the desulfurization mixture according to the invention can contain up to 30 percent by weight of alkali carbonate, preferably in the form of anhydrous soda.

Der Mahlvorgang, insbesondere die Mahldauer, ist für die Herstellung eines optimalen Gemisches hinsichtlich Fließfähigkeit und Entschwefelungswirkung von großer Bedeutung. Durch Erhöhung der Mindestmahldauer von ca. 5 Minuten auf 10 bis 20 Minuten erhält man durch Vergrößerung des tribochemischen Mahleffektes optimale Ergebnisse.The grinding process, in particular the grinding time, is of great importance for the production of an optimal mixture with regard to flowability and desulfurization. By increasing the minimum grinding time from approx. 5 minutes to 10 to 20 minutes, optimal results are obtained by increasing the tribochemical grinding effect.

Mit dem erfindungsgemäß hergestellten Entschwefelungsgemisch ist eine bessere Entschwefelung von Eisenschmelzen wie Roheisen-, Gußeisen- und Stahlschmelzen, bezogen auf die eingesetzte CaC2-Menge, möglich.With the desulfurization mixture produced according to the invention, better desulfurization of molten iron such as pig iron, cast iron and steel melts, based on the amount of CaC 2 used , is possible.

Das Entschwefelungsgemisch führt auf Grund der guten Fließfähigkeit zu keinen Anbackungen, weder in der Lanze noch in deren Zuführungsrohren. Es hat sich weiter gezeigt, daß es bei der Verwendung des Entschwefelungsgemisches zu keinen Schlackenverkrustungen an der Metallpfannenwand kommt. Der Ausstoß an unerwünschten Fluorid-Emissionen während des Entschwefelungsvorganges ist wesentlich niedriger gegenüber einem auf bisher üblichen Wegen hergestellten Calciumcarbid/Calciumfluorid-Gemisch.Due to the good flowability, the desulfurization mixture does not cause caking, neither in the lance nor in its feed pipes. It has also been shown that when the desulfurization mixture is used, there is no slag encrustation on the metal pan wall. The emission of undesired fluoride emissions during the desulfurization process is significantly lower compared to a calcium carbide / calcium fluoride mixture produced in the usual ways.

Die folgenden Beispiele dienen der näheren Erläuterung der erfindungsgemäßen Verfahren zur Herstellung und Anwendung der neuartigen Entschwefelungsgemischen.The following examples serve to explain the processes according to the invention for producing and using the novel desulfurization mixtures in more detail.

Herstellungsbeispiel 1.Production Example 1.

In einer Rohrmühle (Fa. Schriever & Co., Typ Hilda 1700) wurden stündlich 5 000 kg eines Gemisches, bestehend aus 80 Prozent technischem Calciumcarbid (Körnung 7-15 mm, 34 Prozent CaC2), 10 Prozent Calciumkarbonat (Körnung 5-10 mm), 5 Prozent Koksgruß (Körnung < 10 mm), 1,5 Prozent Bauxit (Körnung <0,3 mm) und 3,5 Prozent Flußspat (Körnung 3-15 mm ; 44,0 Prozent F) unter Stickstoffatmosphäre aufgemahlen. Die durchschnittliche Verweildauer des Mahlgutes in der Mühle betrug 15 Minuten.In a tube mill (Schriever & Co., type Hilda 1700) 5,000 kg per hour of a mixture consisting of 80 percent technical calcium carbide (grain size 7-15 mm, 34 percent CaC 2 ), 10 percent calcium carbonate (grain size 5-10 mm), 5 percent coke (grain size <10 mm), 1.5 percent bauxite (grain size <0.3 mm) and 3.5 percent fluorspar (grain size 3-15 mm; 44.0 percent F) ground in a nitrogen atmosphere. The average residence time of the millbase in the mill was 15 minutes.

Das erhaltene Entschwefelungsgemisch hat folgende Analysenwerte :

  • Körnung 99,7 Prozent < 0,5 mm, 90,1 Prozent < 0,1 mm. Der Fluorgehalt von 1,5 Prozent entspricht dem der verarbeiteten Rohstoffe.
The desulfurization mixture obtained has the following analytical values:
  • Grain size 99.7 percent <0.5 mm, 90.1 percent <0.1 mm. The fluorine content of 1.5 percent corresponds to that of the processed raw materials.

Herstellungsbeispiel 2Production Example 2

In einer wie in Beispiel 1 verwendeten Rohrmühle wurden stündlich 4 000 kg eines Gemisches, bestehend aus 70 Prozent technischem Calciumcarbid (Körnung 7-15 mm ; 34 Prozent CaC2), 25 Prozent Calciumkarbonat (Körnung 5-10 mm), 2,0 Prozent Koksgruß (Körnung < 10 mm) und 3,0 Prozent Flußspat (Körnung 3-15 mm ; 44,0 Prozent F) unter Stickstoffatmosphäre aufgemahlen. Die durchschnittliche Verweilzeit des Mahlgutes in der Mühle betrug 20 Minuten. Das erhaltene Entschwefelungsgemisch hat folgende Analysenwerte :

  • Körnung 99,8 Prozent < 0,5 mm, 90,1 Prozent < 0,1 mm. Die chemische Analyse ergab, daß das Entschwefelungsgemisch 1,32 Prozent F, 2,3 Prozent AI203 und 0,5 Prozent Mg0 enthielt. Das Mg0 entstammt den Rohstoffen.
In a tube mill used as in Example 1, 4,000 kg per hour of a mixture consisting of 70 percent technical calcium carbide (grain size 7-15 mm; 34 percent CaC 2 ), 25 percent calcium carbonate (grain size 5-10 mm), 2.0 percent Ground coke (grain size <10 mm) and 3.0 percent fluorspar (grain size 3-15 mm; 44.0 percent F) ground under a nitrogen atmosphere. The average residence time of the millbase in the mill was 20 minutes. The desulfurization mixture obtained has the following analytical values:
  • Grain size 99.8 percent <0.5 mm, 90.1 percent <0.1 mm. The chemical analysis showed that the desulfurization mixture contained 1.32 percent F, 2.3 percent Al 2 O 3 and 0.5 percent MgO. The Mg0 comes from the raw materials.

Anwendungsbeispiel 1Application example 1

In eine mit 350 t flüssigem Roheisen gefüllte Torpedopfanne wurden bei einer Schmelzetemperatur von 1 392 °C während 17 Minuten 880 kg Entschwefelungsgemisch, hergestellt gemäß Herstellungsbeispiel 1, entsprechend 2,5 kg Entschwefelungsgemisch/t Roheisen, durch eine Tauchlanze (Tauchtiefe 2,05 m) mit 20 000 I trockenem Stickstoff eingeblasen. Der Schwefelgehalt wurde von 0,06 auf 0,005 Prozent S gesenkt.In a torpedo pan filled with 350 t of liquid pig iron, 880 kg of desulfurization mixture, produced according to production example 1, corresponding to 2.5 kg of desulfurization mixture / t of pig iron, were passed through a dip lance (immersion depth 2.05 m) at a melt temperature of 1,392 ° C. for 17 minutes. injected with 20,000 l of dry nitrogen. The sulfur content was reduced from 0.06 to 0.005 percent S.

Anwendungsbeispiel 2Example of use 2

In eine mit 150 t flüssigem Stahl gefüllte Metallpfanne wurden bei einer Schmelzetemperatur von 1 490 °C 200 kg Entschwefelungsgemisch, hergestellt gemäß Herstellungsbeispiel 2, entsprechend 1,3 kg Entschwefelungsgemisch/t Stahl, mit 4 000 I Argon über eine Tauchlanze eingeblasen. Die Tauchlanze hatte eine Eintauchtiefe von 2,35 m.In a metal pan filled with 150 t of liquid steel, 200 kg of desulfurization mixture, produced according to production example 2, corresponding to 1.3 kg of desulfurization mixture / t steel, were blown in with 4,000 l of argon at a melt temperature of 1,490 ° C. using an immersion lance. The diving lance had a depth of 2.35 m.

Der Schwefelgehalt wurde von 0,024 auf 0,0025 Prozent S gesenkt.The sulfur content was reduced from 0.024 to 0.0025 percent S.

Anwendungsbeispiel 3Example of use 3

In eine mit 150 t flüssigem Stahl gefüllte Metallpfanne wurden bei einer Schmelzetemperatur von 1 480 °C 400 kg Entschwefelungsgemisch, hergestellt gemäß Herstellungsbeispiel 2, entsprechend 2,7 kg Entschwefelungsgemisch/t Stahl, mit 8000 I Argon über eine Tauchlanze eingeblasen. Die Tauchlanze hatte eine Eintauchtiefe von 2,35 m.In a metal pan filled with 150 t of liquid steel, 400 kg of desulfurization mixture, produced according to Production Example 2, were correspondingly 2.7 kg at a melt temperature of 1,480 ° C. Desulphurization mixture / t steel, injected with 8000 I argon via a submersible lance The diving lance had a depth of 2.35 m.

Der Schwefelgehalt wurde von 0,025 auf 0,0007 Prozent S gesenkt.The sulfur content was reduced from 0.025 to 0.0007 percent S.

Claims (7)

1. A process for producing a desulfurization mixture based on calcium carbide for metal melts, which comprises grinding a mixture composed of
32 to 89 % by weight of calcium carbide
5 to 66 % by weight of calcium oxide
0.1 to 45 % by weight of an alkaline earth metal carbonate
0.1 to 10 % by weight of alumina
0.1 to 10 % by weight of not chemically bound carbon '
0.3 to 4.5 % by weight of calcium fluoride

in a grain size from 0.1 to 50 mm as a homogeneous mixture by a grinding step under a dry inert gas atmosphere in a mill to a size of < 0.5 mm and grinding the material to be ground for 3 to 30 minutes in the mill.
2. The process as claimed in claim 1, wherein 0.25 to 1.7 % by weight of fluorine are introduced.
3. The process as claimed in claim 1 or 2, characterized in that a technical carbide having a CaC2 content of 20 to 80 % by weight is used.
4. The process as claimed in any of claims 1 to 3, wherein limestone and/or dolomite are introduced as the alkaline earth metal carbonate.
5. The process as claimed in any of claims 1 to 4, wherein up to 30 % by weight of an alkaline metal carbonate are introduced.
6. The process as claimed in any of claims 1 to 5, wherein nitrogen is used as the inert gas.
7. The process as claimed in any of claims 1 to 6, wherein at least 85 % by weight of the end product are ground down by the grinding step to a grain size of < 0.1 mm.
EP86113501A 1985-10-03 1986-10-01 Mixture for desulfurizing metal melts, process for manufacturing it and its use Expired EP0220522B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86113501T ATE48652T1 (en) 1985-10-03 1986-10-01 DESULPHURIZATION MIXTURE FOR METAL MELT, A PROCESS FOR ITS PRODUCTION AND ITS USE.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3535280 1985-10-03
DE19853535280 DE3535280A1 (en) 1985-10-03 1985-10-03 DESULFURATION MIXTURE FOR METAL MELTS, A METHOD FOR THE PRODUCTION THEREOF AND ITS USE

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EP0220522A1 EP0220522A1 (en) 1987-05-06
EP0220522B1 true EP0220522B1 (en) 1989-12-13

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EP (1) EP0220522B1 (en)
JP (1) JPH0733534B2 (en)
AT (1) ATE48652T1 (en)
DD (1) DD249922A5 (en)
DE (2) DE3535280A1 (en)
ES (1) ES2012038B3 (en)
IN (1) IN167748B (en)
PL (1) PL146624B1 (en)

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AT406690B (en) * 1994-12-09 2000-07-25 Donau Chemie Ag AGENT FOR TREATING RAW IRON AND CAST IRON MELT FOR THE PURPOSE OF DESULFURATION
PL213251B1 (en) 2009-02-02 2013-02-28 Akad Gorniczo Hutnicza Method of manufacturing slag-forming mixture for the secondary steel refining in a ladle or in a ladle furnace

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JPS55110712A (en) * 1979-02-15 1980-08-26 Kawasaki Steel Corp Desulfurizing agent for blowing-in
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DE2920353A1 (en) * 1979-05-19 1980-11-27 Hoechst Ag METHOD FOR THE PRODUCTION OF DEHANIZING AGENTS FOR CRUDE IRON OR STEEL MELT
JPS5770219A (en) * 1980-10-21 1982-04-30 Nisshin Steel Co Ltd Method for dephosphorizing, desulfurizing and denitrifying iron alloy
DE3111509A1 (en) * 1981-03-24 1982-10-07 Hoechst Ag, 6000 Frankfurt METHOD FOR THE PRODUCTION OF DESULFURING AGENTS FOR BOD IRON OR STEEL MELT
ATE11572T1 (en) * 1981-07-27 1985-02-15 Thyssen Aktiengesellschaft Vorm. August Thyssenh¨Tte PROCESS FOR REDUCING THE IRON CONTENT OF CAO-RICH SLAG RESULTING FROM THE DESULPHURIZATION OF PIG IRON.
US4541867A (en) * 1984-03-20 1985-09-17 Amax Inc. Varnish-bonded carbon-coated magnesium and aluminum granules

Also Published As

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JPH0733534B2 (en) 1995-04-12
DE3667493D1 (en) 1990-01-18
IN167748B (en) 1990-12-15
ES2012038B3 (en) 1990-03-01
PL146624B1 (en) 1989-02-28
JPS6286108A (en) 1987-04-20
DE3535280A1 (en) 1987-04-09
US4687512A (en) 1987-08-18
ATE48652T1 (en) 1989-12-15
EP0220522A1 (en) 1987-05-06
DD249922A5 (en) 1987-09-23
PL261682A1 (en) 1987-09-07

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