[go: up one dir, main page]

EP0061011B1 - Process for producing desulfurizing agents for pig iron or steel melts - Google Patents

Process for producing desulfurizing agents for pig iron or steel melts Download PDF

Info

Publication number
EP0061011B1
EP0061011B1 EP82101427A EP82101427A EP0061011B1 EP 0061011 B1 EP0061011 B1 EP 0061011B1 EP 82101427 A EP82101427 A EP 82101427A EP 82101427 A EP82101427 A EP 82101427A EP 0061011 B1 EP0061011 B1 EP 0061011B1
Authority
EP
European Patent Office
Prior art keywords
mixture
weight
calcium oxide
calcium
cao
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP82101427A
Other languages
German (de)
French (fr)
Other versions
EP0061011A1 (en
Inventor
Albert Braun
Willi Dr. Portz
Georg Dr. Strauss
Hans-Martin Dipl.-Ing. Delhey
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Krupp Stahl AG
Hoechst AG
Original Assignee
Krupp Stahl AG
Hoechst AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Krupp Stahl AG, Hoechst AG filed Critical Krupp Stahl AG
Priority to AT82101427T priority Critical patent/ATE9596T1/en
Publication of EP0061011A1 publication Critical patent/EP0061011A1/en
Application granted granted Critical
Publication of EP0061011B1 publication Critical patent/EP0061011B1/en
Expired legal-status Critical Current

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
    • C21C1/025—Agents used for 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
    • C21C7/0645—Agents used for dephosphorising or desulfurising

Definitions

  • the present invention relates to a process for the production of desulfurization agents based on calcium oxide-containing calcium carbide for pig iron and steel melts, a calcium carbide-calcium oxide melt mixture having a CaO content of 20 to 80% by weight first being produced from lime and coke, which is allowed to solidify into a block by allowing it to cool; then, while the solidified block still has an average temperature of more than 400 ° C., it is broken down to grain sizes of less than 150 mm and calcium oxide is added to the comminuted mixture, which is still at least 400 ° C., in accordance with the CaO content desired in the end product, and the mixture is then ground with vigorous mixing to grain sizes of less than 10 mm.
  • a method is already known from EP-A2-19 086.
  • DE-C3-2 037 758 describes a process for the production of calcium carbide for the desulfurization of molten metals by introducing quicklime (CaO) and fluorspar into molten calcium carbide.
  • the additives are used with a content of adhesive and crystal water less than 5% by weight.
  • the burnt lime can be partially replaced by a gas-releasing substance such as limestone, which increases the porosity of the carbide and thus the active surface offered during the desulfurization.
  • Coke breeze can also be added to the carbide.
  • DE-C3-22 36160 describes an agent for the desulfurization of liquid pig iron based on calcium oxide, the reactive calcium oxide carbon, e.g. B. in the form of carbon black, and may contain calcium carbide.
  • Desulphurization agents based on calcium carbide which contain substances which release water at the temperature of the molten metal, are already known from DE-B2-22 52 795.
  • These agents which are mixtures of commercially available carbide with, for example, Ca (OH) 2 as water-releasing substance and possibly carbon and calcium carbonate, have the disadvantage that they are mixtures produced by mechanical mixing, in which carbide particles are separated apart from Ca (OH) 2 - Particles are present, which leads to a higher consumption, uneven and violent gas reactions and a large spread with regard to the desulfurization effect when using these products, which makes a targeted use of these agents difficult.
  • the older, unpublished EP-A1-31 534 relates to a process for the production of desulfurizing agents with a content of 1-6% by weight of chemically bound water based on calcium oxide-containing calcium carbide for pig iron and steel melts, which is characterized in that that a calcium carbide-calcium oxide melt mixture with a CaO content of 20 to 80% by weight is first produced from lime and coke, which mixture is allowed to solidify into a block by allowing it to cool; that one, while the solidified block still has an average temperature of more than 400 ° C, breaks it down to grain sizes less than 150 mm and gives up on the crushed and still at least 400 ° C hot mixture calcium oxide in such an amount that the resulting mixture resulting total CaO content corresponds to the desired CaO content in the end product, then the mixture with intensive mixing and in the presence of air or nitrogen with a moisture content of 5 to 20 g / m 3 (at 1.013 bar and 273.15 K) Grind temperatures below 100 ° C to grain sizes smaller than 10
  • the end product When mixing with free carbon and carbonate, it is preferred to add such an amount that the end product contains 0.5 to 8% by weight of free carbon and 0.5 to 20% by weight of carbonates of calcium, magnesium or sodium. In addition, the end product preferably contains 1-6% by weight of chemically bound water. The intensive mixing and grinding is best carried out at 10-50 ° C.
  • a calcium carbide-calcium oxide starting melt mixture with a CaO content of 20 to 45% by weight which was obtained in a known manner from lime and coke by thermal means.
  • the process according to the invention and the process of EP-A2-19 086 have the further advantages that a specific Möller composition is not set in each case to produce the carbide melt and the Lime does not have to be finely ground to a certain grain size beforehand, but that a carbide block can be assumed whose C a C 2 : CaO weight ratio can fluctuate within a very wide range, ie can be practically arbitrary, and the lime also in coarse-grained form, for example in a grain size between 8 and 60 mm, can be used.
  • composition according to the invention is that present on the surface of each grain Ca (OH) 2 close to CaC 2, is set very early and uniformly in motion whereby the desulfurizing reaction. With comparable desulfurization results, smaller amounts of the desulfurization agent are required and more targeted results are possible.
  • the block After the block had cooled to an average temperature of about 600 ° C, it was pre-broken to grain sizes smaller than 150 mm and the carbide, which was still 500 ° G hot, was overlaid with so much lime with a grain size of 8 to 60 mm that the resulting mixture contained a total CaO content of 50% by weight.
  • 850 kg of this mixture were mixed with 100 kg limestone (grain size less than 1 mm) and 50 kg of coke breeze (grain size less than 3 mm) and with passage of 1,500 m 3 / h of air with a moisture content of 10 g / m 3 (at 15 ° C) in a rotary mill with a throughput of 500 kg / h at 50 ° C to grain sizes between 0 and 0.1 mm.
  • the product obtained contained 2% by weight of chemically bound water.
  • Calcium carbide is produced thermally from lime and coke in a known manner, the lime-coke mixture in the entire Möller being adjusted to a weight ratio of approximately 110:40, which corresponds to a carbide with a CaO content of approximately 45% by weight.
  • CaO with a grain size of 3-8 mm is added to the tapping jet of this carbide in such an amount that an average content of approx. 80% by weight CaO results in the tapping crucible (approx. .
  • the block is pre-crushed to a grain size of less than 150 mm and as much lime with a grain size of 8 to 60 mm is layered on the hot mixture. That the average CaO content is 90% by weight.
  • 875 kg of this mixture are mixed with 100 kg limestone (grain size less than 1 mm) and 25 kg of coke breeze (grain size less than 3 mm) and with passage of 1,500 m 3 / h of air with a moisture content of 10 g / m 3 (at 15 ° C) in a rotary mill with a throughput of 500 kg / h at 50 ° C to a grain size less than 0.1 mm.
  • the product obtained contains 2.5% by weight of chemically bound water.

Landscapes

  • 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)
  • Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)
  • Manufacture And Refinement Of Metals (AREA)

Abstract

The disclosure relates to a process for the manufacture of desulfurizing agents containing 1-6 weight % chemically combined water, based on calcium oxide and carbon-containing calcium carbide, for crude iron and steel melts. More particularly, the disclosure provides for a molten mixture of calcium carbide and calcium oxide containing 20 to 80 weight % CaO to be made from lime and coke; for the mixture to be allowed to cool and solidify into a block; for the solidified block while it still has an average temperature of more than 400 DEG C. to be crushed to particles with a size of less than 150 mm; for the comminuted mixture, which still has a temperature of at least 400 DEG C. to be admixed with a quantity of calcium oxide necessary to establish in the resulting mixture a total content of CaO corresponding to the CaO content desired in the end product; and for the mixture to be gound while intensively mixing it with free carbon and carbonate in the presence of air or nitrogen with a moisture content of 5 to 20 g/m3 (at 1.013 bar and 273.15 K.) at temperatures below 100 DEG C. to particles with a size of less than 10 mm.

Description

Die vorliegende Erfindung betrifft ein Verfahren zur Herstellung von Entschwefelungsmitteln auf Basis von Calciumoxid enthaltendem Calciumcarbid für Roheisen- und Stahlschmelzen, wobei man zunächst aus Kalk und Koks ein Calciumcarbid-Calciumoxid-Schmelzgemisch mit einem CaO-Gehalt von 20 bis 80 Gew.-% erzeugt, welches man durch Abkühlenlassen zu einem Block erstarren läßt ; wobei man dann, während der erstarrte Block noch eine Durchschnittstemperatur von mehr als 400 °C aufweist, diesen auf Korngrößen kleiner als 150 mm vorbricht und auf das zerkleinerte und noch mindestens 400 °C heiße Gemisch Calciumoxid entsprechend dem im Endprodukt gewünschten CaO-Gehalt aufgibt, und wobei man anschließend die Mischung unter intensiver Vermengung auf Korngrößen kleiner als 10 mm mahlt. Ein derartiges Verfahren ist bereits aus EP-A2-19 086 bekannt.The present invention relates to a process for the production of desulfurization agents based on calcium oxide-containing calcium carbide for pig iron and steel melts, a calcium carbide-calcium oxide melt mixture having a CaO content of 20 to 80% by weight first being produced from lime and coke, which is allowed to solidify into a block by allowing it to cool; then, while the solidified block still has an average temperature of more than 400 ° C., it is broken down to grain sizes of less than 150 mm and calcium oxide is added to the comminuted mixture, which is still at least 400 ° C., in accordance with the CaO content desired in the end product, and the mixture is then ground with vigorous mixing to grain sizes of less than 10 mm. Such a method is already known from EP-A2-19 086.

Weiterhin beschreibt die DE-C3-2 037 758 ein Verfahren zur Herstellung von Calciumkarbid zur Entschwefelung von Metallschmelzen durch Eintragen von gebranntem Kalk (CaO) und Flußspat in schmelzflüssiges Calciumkarbid. Die Zuschlagstoffe werden hierbei mit einem Gehalt an Haft-und Kristallwasser kleiner als 5 Gewichts-% eingesetzt. Der gebrannte Kalk kann teilweise durch einen gasabspaltenden Stoff, wie Kalkstein, ersetzt werden, wodurch die Porösität des Karbides und damit dessen bei der Entschwefelung angebotene aktive Oberfläche vergrößert werden. Außerdem kann dem Karbid auch Koksgrus zugesetzt werden.Furthermore, DE-C3-2 037 758 describes a process for the production of calcium carbide for the desulfurization of molten metals by introducing quicklime (CaO) and fluorspar into molten calcium carbide. The additives are used with a content of adhesive and crystal water less than 5% by weight. The burnt lime can be partially replaced by a gas-releasing substance such as limestone, which increases the porosity of the carbide and thus the active surface offered during the desulfurization. Coke breeze can also be added to the carbide.

Die DE-C3-22 36160 beschreibt ein Mittel zur Entschwefelung von flüssigem Roheisen auf Calciumoxidbasis, wobei das bevorzugt als poröses Granulat vorliegende, reaktionsfähige Calciumoxid Kohlenstoff, z. B. in Form von Ruß, und Calciumcarbid enthalten kann.DE-C3-22 36160 describes an agent for the desulfurization of liquid pig iron based on calcium oxide, the reactive calcium oxide carbon, e.g. B. in the form of carbon black, and may contain calcium carbide.

Entschwefelungsmittel auf der Basis von Calciumcarbid, welche Stoffe enthalten, die bei der Temperatur der Metallschmelze Wasser abspalten, sind bereits aus der DE-B2-22 52 795 bekannt. Diese Mittel, welche Mischungen von handelsüblichem Carbid mit beispielsweise Ca(OH)2 als wasserabspaltendem Stoff und ggf. Kohlenstoff und Calciumcarbonat darstellen, haben den Nachteil, daß sie durch mechanisches Vermischen hergestellte Gemenge sind, in denen Carbidteilchen getrennt neben Ca(OH)2-Teilchen vorliegen, was bei Einsatz dieser Produkte zu einem höheren Verbrauch, ungleichmäßigen und heftigen Gasreaktionen und einer großen Streubreite bezüglich der Entschwefelungswirkung führt, wodurch ein gezielter Einsatz dieser Mittel erschwert wird.Desulphurization agents based on calcium carbide, which contain substances which release water at the temperature of the molten metal, are already known from DE-B2-22 52 795. These agents, which are mixtures of commercially available carbide with, for example, Ca (OH) 2 as water-releasing substance and possibly carbon and calcium carbonate, have the disadvantage that they are mixtures produced by mechanical mixing, in which carbide particles are separated apart from Ca (OH) 2 - Particles are present, which leads to a higher consumption, uneven and violent gas reactions and a large spread with regard to the desulfurization effect when using these products, which makes a targeted use of these agents difficult.

Schließlich betrifft die ältere, nicht vorveröffentlichte EP-A1-31 534 ein Verfahren zur Herstellung von Entschwefelungsmitteln mit einem Gehalt von 1-6 Gew.-% chemisch gebundenem Wasser auf basis von Calciumoxid enthaltendem Calciumcarbid für Roheisen- und Stahlschmelzen, welches dadurch gekennzeichnet ist, daß man zunächst aus Kalk und Koks ein Calciumcarbid-Calciumoxid-Schmelzgemisch mit einem CaO-Gehalt von 20 bis 80 Gew.-% erzeugt, welches man durch Abkühlenlassen zu einem Block erstarren läßt ; daß man, während der erstarrte Block noch eine Durchschnittstemperatur von mehr als 400 °C aufweist, diesen auf Korngrößen kleiner als 150 mm vorbricht und auf das zerkleinerte und noch mindestens 400 °C heiße Gemisch Calciumoxid in einer solchen Menge aufgibt, daß der sich in der entstehenden Mischung ergebende Gesamtgehalt an CaO dem im Endprodukt gewünschten CaO-Gehalt entspricht, anschließend die Mischung unter intensiver Vermengung und in Gegenwart von Luft oder Stickstoff mit einem Feuchtigkeitsgehalt von 5 bis 20 g/m3 (bei 1,013 bar und 273,15 K) bei Temperaturen unterhalb 100 °C auf Korngrößen kleiner als 10 mm mahlt.Finally, the older, unpublished EP-A1-31 534 relates to a process for the production of desulfurizing agents with a content of 1-6% by weight of chemically bound water based on calcium oxide-containing calcium carbide for pig iron and steel melts, which is characterized in that that a calcium carbide-calcium oxide melt mixture with a CaO content of 20 to 80% by weight is first produced from lime and coke, which mixture is allowed to solidify into a block by allowing it to cool; that one, while the solidified block still has an average temperature of more than 400 ° C, breaks it down to grain sizes less than 150 mm and gives up on the crushed and still at least 400 ° C hot mixture calcium oxide in such an amount that the resulting mixture resulting total CaO content corresponds to the desired CaO content in the end product, then the mixture with intensive mixing and in the presence of air or nitrogen with a moisture content of 5 to 20 g / m 3 (at 1.013 bar and 273.15 K) Grind temperatures below 100 ° C to grain sizes smaller than 10 mm.

Es wurde nun gefunden, daß man die Nachteile der bekannten Arbeitsweisen vermeiden und ein hochwirksames Entschwefelungsmittel für Roheisen- und Stahlschmelzen erhalten kann, wenn man die intensive Vermengung und Vermahlung unter Zugabe von freiem Kohlenstoff und Carbonat in Gegenwart von Luft oder Stickstoff mit einem Feuchtigkeitsgehalt von 5 bis 20 g/m3 (bei 1,013 bar und 273,15 K) bei Temperaturen unterhalb 100 °C durchführt. Der erstarrte Block hat eine Durchschnittstemperatur von vorzugsweise zwischen 400 °C und der Erstarrungstemperatur der Schmelze, bevor man ihn auf Korngrößen kleiner als 150 mm vorbricht. Vorzugsweise gibt man auf das zerkleinerte und noch mindestens 400 °C heiße Gemisch so viel Calciumoxid auf, daß sich in der Mischung ein Gesamtgehalt an CaO von über 45 bis 90 Gew.-% ergibt. Anschließend wird dann diese Mischung unter intensiver Vermengung auf Korngrößen vorzugsweise kleiner als 0,1 mm gemahlen.It has now been found that the disadvantages of the known procedures can be avoided and a highly effective desulfurizing agent for pig iron and steel melts can be obtained if the intensive mixing and grinding with the addition of free carbon and carbonate in the presence of air or nitrogen with a moisture content of 5 up to 20 g / m 3 (at 1.013 bar and 273.15 K) at temperatures below 100 ° C. The solidified block has an average temperature of preferably between 400 ° C. and the solidification temperature of the melt, before being broken down to grain sizes smaller than 150 mm. So much calcium oxide is preferably added to the comminuted mixture, which is still at least 400 ° C., that a total CaO content of over 45 to 90% by weight results in the mixture. This mixture is then ground with vigorous mixing to grain sizes, preferably less than 0.1 mm.

Bei der Vermengung mit freiem Kohlenstoff und Carbonat gibt man bevorzugt eine solche Menge davon zu, daß das Endprodukt 0,5 bis 8 Gew.-% freien Kohlenstoff und 0,5 bis 20 Gew.-% Carbonate des Calciums, Magnesiums oder Natriums enthält. Außerdem enthält das Endprodukt bevorzugt 1-6 Gew.-% chemisch gebundenes Wasser. Die intensive Vermengung und Vermahlung führt man zweckmäßig bei 10-50 °C durch.When mixing with free carbon and carbonate, it is preferred to add such an amount that the end product contains 0.5 to 8% by weight of free carbon and 0.5 to 20% by weight of carbonates of calcium, magnesium or sodium. In addition, the end product preferably contains 1-6% by weight of chemically bound water. The intensive mixing and grinding is best carried out at 10-50 ° C.

Vorzugsweise setzt man ein Calciumcarbid-Calciumoxid-Ausgangsschmelzgemisch mit einem CaO-Gehalt von 20 bis 45 Gew.-% ein, das in bekannter Weise auf thermischem Wege aus Kalk und Koks gewonnen wurde. Man kann aber auch so verfahren, daß man zunächst ein Calciumcarbid-Calciumoxid-Ausgangsschmelzgemisch mit einem CaO-Gehalt von über 45 bis 80 Gew.-% herstellt, indem man in eine vorliegende Calciumcarbidschmelze, die einen Caiciumoxidgehalt bis zu 45 Gew.-% aufweist, feinteiliges Calciumoxid bis zu einem CaO-Gehalt von höchstens 80 Gew.-% einträgt und erst dann das Ganze zu einem Block erstarren läßt, bevor man diesen bei Temperaturen oberhalb 400 °C vorbricht. Außer daß das Vermischen des Kalkes mit einer Carbidschmelze und den damit verbundenen Schwierigkeiten vermieden werden kann, besitzt das erfindungsgemäße Verfahren ebenso wie das Verfahren der EP-A2-19 086 die weiteren Vorteile, daß zur Erzeugung der Carbidschmelze nicht jeweils eine bestimmte Möllerzusammensetzung eingestellt und der Kalk vorher nicht auf eine bestimmte Korngröße feingemahlen werden muß, sondern daß von einem Carbidblock ausgegangen werden kann, dessen CaC2 : CaO-Gewichtsverhältnis innerhalb eines sehr weiten Bereiches schwanken, d. h. praktisch beliebig sein kann, und der Kalk auch in grobkörniger Form, beispielsweise in einer Korngröße zwischen 8 und 60 mm, eingesetzt werden kann.It is preferable to use a calcium carbide-calcium oxide starting melt mixture with a CaO content of 20 to 45% by weight, which was obtained in a known manner from lime and coke by thermal means. One can also doing so, by first preparing a calcium-calcia source melt mixture with a CaO content of about 45 to 8 0 wt .-% by a present Calciumcarbidschmelze that a Caiciumoxidgehalt up to 45 wt .-% has, finely divided calcium oxide up to a CaO content of maximum enters at least 80% by weight and only then solidifies the whole into a block before breaking it at temperatures above 400 ° C. In addition to the fact that the mixing of the lime with a carbide melt and the difficulties associated with it can be avoided, the process according to the invention and the process of EP-A2-19 086 have the further advantages that a specific Möller composition is not set in each case to produce the carbide melt and the Lime does not have to be finely ground to a certain grain size beforehand, but that a carbide block can be assumed whose C a C 2 : CaO weight ratio can fluctuate within a very wide range, ie can be practically arbitrary, and the lime also in coarse-grained form, for example in a grain size between 8 and 60 mm, can be used.

Ein weiterer Vorteil des erfindungsgemäß hergestellten Mittels besteht darin, daß auf der Oberfläche jedes einzelnen Kornes Ca(OH)2 dicht neben CaC2 vorliegt, wodurch die Entschwefelungsreaktion sehr früh und gleichmäßig in Gang gesetzt wird. Dadurch werden bei vergleichbaren Entschwefelungsergebnissen geringere Mengen des Entschwefelungsmittels benötigt und gezieltere Ergebnisse ermöglicht.A further advantage of the composition according to the invention is that present on the surface of each grain Ca (OH) 2 close to CaC 2, is set very early and uniformly in motion whereby the desulfurizing reaction. With comparable desulfurization results, smaller amounts of the desulfurization agent are required and more targeted results are possible.

Beispiel 1example 1

Aus einer für die Herstellung von technischem Carbid üblichen Schmelze mit einem CaCz-Gehalt von 80 Gew.-% und CaO-Gehalt von 20 Gew.-% wurde in einem Tiegel durch Abkühlenlassen dieser Schmelze in bekannter Weise ein Carbidblock entsprechender Zusammensetzung erzeugt.From a melt customary for the production of technical carbide with a CaC z content of 80% by weight and a CaO content of 20% by weight, a carbide block of corresponding composition was produced in a crucible in a known manner by allowing this melt to cool.

Nachdem sich der Block auf eine Durchschnittstemperatur von etwa 600 °C abgekühlt hatte, wurde er auf Korngrößen kleiner als 150 mm vorgebrochen und das noch 500 °G heiße Carbid mit so viel Kalk einer Korhgröße von 8 bis 60 mm überschichtet, daß die sich ergebende Mischung einen CaO-Gehalt von insgesamt 50 Gew.-% enthielt. 850 kg dieser Mischung wurden mit 100 kg Kalkstein (Körnung kleiner 1 mm) und 50 kg Koksgrus (Körnung kleiner 3 mm) vermischt und unter Durchleiten von 1 500 m3/h Luft mit einem Feucntigkeitsgehalt von 10 g/m3 (bei 15 °C) in einer Rotationsmühle mit einem Durchsatz von 500 kg/h bei 50 °C auf Korngrößen zwischen 0 und 0,1 mm gemahlen. Das erhaltene Produkt enthielt 2 Gew.-% chemisch gebundenes Wasser.After the block had cooled to an average temperature of about 600 ° C, it was pre-broken to grain sizes smaller than 150 mm and the carbide, which was still 500 ° G hot, was overlaid with so much lime with a grain size of 8 to 60 mm that the resulting mixture contained a total CaO content of 50% by weight. 850 kg of this mixture were mixed with 100 kg limestone (grain size less than 1 mm) and 50 kg of coke breeze (grain size less than 3 mm) and with passage of 1,500 m 3 / h of air with a moisture content of 10 g / m 3 (at 15 ° C) in a rotary mill with a throughput of 500 kg / h at 50 ° C to grain sizes between 0 and 0.1 mm. The product obtained contained 2% by weight of chemically bound water.

Mit 1 500 kg dieses Produktes wurden 300 000 kg einer Roheisenschmelze, die 0,03 Gew.-% Schwefel enthielt, in bekannter Weise entschwefelt. Der S-Gehalt des behandelten Eisens betrug weniger als 0,005 Gew.-%.With 1,500 kg of this product, 300,000 kg of a pig iron melt which contained 0.03% by weight of sulfur were desulfurized in a known manner. The S content of the treated iron was less than 0.005% by weight.

Beispiel 2Example 2

In bekannter Weise wird aus Kalk und Koks Calciumcarbid thermisch hergestellt, wobei die Kalk-Koks-Mischung im gesamten Möller auf ein Gewichtsverhältnis von etwa 110:40 eingestellt wird, was einem Carbid mit einem CaO-Gehalt von etwa 45 Gew.-% entspricht.Calcium carbide is produced thermally from lime and coke in a known manner, the lime-coke mixture in the entire Möller being adjusted to a weight ratio of approximately 110:40, which corresponds to a carbide with a CaO content of approximately 45% by weight.

Dem Abstichstrahl dieses Carbides wird CaO der Körnung 3-8 mm in einer solchen Menge zudosiert, daß sich im Abstichtiegel ein Durchschnittsgehalt von ca. 80 Gew.-% CaO ergibt (auf 1 Tonne Abstichstrahl etwa 1,2-1,3 t CaO).CaO with a grain size of 3-8 mm is added to the tapping jet of this carbide in such an amount that an average content of approx. 80% by weight CaO results in the tapping crucible (approx. .

Nach dem Abkühlen des Tiegels auf eine Durchschnittstemperatur von nicht unter 600°C, was bereits nach 4 Stunden der Fall ist, wird der Block auf eine Korngröße kleiner als 150 mm vorgebrochen und auf das heiße Gemisch soviel Kalk der Körnung 8 bis 60 mm geschichtet, daß der Durchschnitts-CaO-Gehalt 90 Gew.-% beträgt. 875 kg dieser Mischung werden mit 100 kg Kalkstein (Körnung kleiner 1 mm) und 25 kg Koksgrus (Körnung kleiner 3 mm) vermischt und unter Durchleiten von 1 500 m3/h Luft mit einem Feuchtigkeitsgehalt von 10 g/m3 (bei 15 °C) in einer Rotationsmühle mit einem Durchsatz von 500 kg/h bei 50 °C auf eine Korngröße kleiner als 0,1 mm gemahlen. Das erhaltene Produkt enthält 2,5 Gew.-% chemisch gebundenes Wasser.After the crucible has cooled to an average temperature of not less than 600 ° C, which is already the case after 4 hours, the block is pre-crushed to a grain size of less than 150 mm and as much lime with a grain size of 8 to 60 mm is layered on the hot mixture. that the average CaO content is 90% by weight. 875 kg of this mixture are mixed with 100 kg limestone (grain size less than 1 mm) and 25 kg of coke breeze (grain size less than 3 mm) and with passage of 1,500 m 3 / h of air with a moisture content of 10 g / m 3 (at 15 ° C) in a rotary mill with a throughput of 500 kg / h at 50 ° C to a grain size less than 0.1 mm. The product obtained contains 2.5% by weight of chemically bound water.

Mit diesem Gemisch werden, bezogen auf den Calciumcarbidgehalt, die gleichen Entschwefelungsergebnisse erzielt, wie im Beispiel 1 geschildert.With this mixture, based on the calcium carbide content, the same desulfurization results are achieved as described in Example 1.

Claims (4)

1. Process for the manufacture of desulfurizing agents based on calcium carbide containing calcium oxide for crude iron and steel melts, wherein a molten calcium carbide/calcium oxide-mixture containing 20 to 80 weight % CaO is first produced from lime and coke and then allowed to cool and solidify into a block, the solidified block is precrushed while it still has an average temperature of more than 400 °C to particles with a size of less than 150 mm ; the comminuted mixture, which still has a temperature of at least 400 °C, is admixed with a quantity of calcium oxide corresponding to the CaO content desired in the end product ; and the mixture is subsequently ground with thorough agitation to particles with a size of less than 10 mm, which comprises thoroughly agitating and grinding the mixture with addition of free carbon and carbonate in the presence of air or nitrogen with a moisture content of 5 to 20 g/m3 (at 1.013 bar and 273.15 K) at temperatures below 100°C.
2. Process as claimed in claim 1, wherein the final product contains 0.5 to 8 weight % free carbon and 0.5 to 20 weight % carbonates of calcium, magnesium or sodium.
3. Process as claimed in claim 1 or 2, wherein the final product contains 1 to 6 weight % chemically combined water.
4. Process as claimed in claim 1, wherein the mixture is intensively agitated and is ground at 10-50 °C.
EP82101427A 1981-03-24 1982-02-25 Process for producing desulfurizing agents for pig iron or steel melts Expired EP0061011B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT82101427T ATE9596T1 (en) 1981-03-24 1982-02-25 PROCESS FOR THE MANUFACTURE OF DESULPHURIZING AGENTS FOR MELTED PIG IRON OR STEEL.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3111509 1981-03-24
DE19813111509 DE3111509A1 (en) 1981-03-24 1981-03-24 METHOD FOR THE PRODUCTION OF DESULFURING AGENTS FOR BOD IRON OR STEEL MELT

Publications (2)

Publication Number Publication Date
EP0061011A1 EP0061011A1 (en) 1982-09-29
EP0061011B1 true EP0061011B1 (en) 1984-09-26

Family

ID=6128139

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82101427A Expired EP0061011B1 (en) 1981-03-24 1982-02-25 Process for producing desulfurizing agents for pig iron or steel melts

Country Status (10)

Country Link
US (1) US4400292A (en)
EP (1) EP0061011B1 (en)
JP (1) JPS57169010A (en)
AT (1) ATE9596T1 (en)
BR (1) BR8201618A (en)
CA (1) CA1184384A (en)
DD (1) DD202183A5 (en)
DE (2) DE3111509A1 (en)
ES (1) ES8302104A1 (en)
ZA (1) ZA821939B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3535280A1 (en) * 1985-10-03 1987-04-09 Hoechst Ag DESULFURATION MIXTURE FOR METAL MELTS, A METHOD FOR THE PRODUCTION THEREOF AND ITS USE

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1408188A1 (en) * 1959-12-19 1968-10-17 Hoesch Ag Process for desulphurization of pig iron baths
AT264560B (en) * 1966-08-25 1968-09-10 Gustav Dipl Ing Wolfram Basic steelmaking process
DE2037758C3 (en) * 1970-07-30 1979-08-02 Hoechst Ag, 6000 Frankfurt Process for the production of calcium carbide for the desulfurization of metal melts
LU63607A1 (en) * 1971-07-26 1973-02-05
DE2252795C3 (en) * 1972-10-27 1982-09-09 Skw Trostberg Ag, 8223 Trostberg Desulphurizing agent for pig iron and ferro-alloy melts
DE2326539C3 (en) * 1973-05-24 1975-11-13 Sueddeutsche Kalkstickstoff-Werke Ag, 8223 Trostberg Process for the production of a desulphurisation mixture for iron melts from calcium carbide and at least one water-containing substance
IT1047585B (en) * 1975-09-26 1980-10-20 Centro Speriment Metallurg PERFECTION FOR DEOXIDATION AND DESULFURATION OF STEEL
DE2741588C2 (en) * 1977-09-15 1985-02-07 Skw Trostberg Ag, 8223 Trostberg Agent for desulphurising molten iron
DE2919324A1 (en) * 1979-05-14 1980-12-04 Hoechst Ag DEHANIZER FOR RAW IRON AND STEEL MELTING AND A METHOD FOR THE PRODUCTION THEREOF
DE2920353A1 (en) * 1979-05-19 1980-11-27 Hoechst Ag METHOD FOR THE PRODUCTION OF DEHANIZING AGENTS FOR CRUDE IRON OR STEEL MELT
DE2952686A1 (en) * 1979-12-29 1981-07-02 Hoechst Ag, 6230 Frankfurt METHOD FOR THE PRODUCTION OF DESULFURING AGENTS FOR BOD IRON OR STEEL MELT
ES497686A0 (en) * 1979-12-29 1981-11-01 Hoechst Ag PROCEDURE FOR THE PREPARATION OF AN AGENT FOR THE DE-SULFURATION OF METALLIC CAST MASSES

Also Published As

Publication number Publication date
DD202183A5 (en) 1983-08-31
ZA821939B (en) 1983-02-23
DE3111509A1 (en) 1982-10-07
JPS57169010A (en) 1982-10-18
ES510769A0 (en) 1983-02-01
CA1184384A (en) 1985-03-26
ATE9596T1 (en) 1984-10-15
US4400292A (en) 1983-08-23
DE3260809D1 (en) 1984-10-31
EP0061011A1 (en) 1982-09-29
BR8201618A (en) 1983-02-08
JPH0135883B2 (en) 1989-07-27
ES8302104A1 (en) 1983-02-01

Similar Documents

Publication Publication Date Title
EP0061012B1 (en) Process for producing desulfurizing agents for pig iron and steel melts
EP0164592A1 (en) Fine-grained desulfurization agent forron melts, and process for the desulfurization of molten pig iron
EP0019086B1 (en) Process for producing desulfurizing agents for pig iron or steel melts
DE2247497A1 (en) PROCESS FOR THE EXTRACTION OF COPPER, NICKEL, COBALT AND MOLYBDA FROM DEEP-SEA MANGNOLLES
EP0031534B1 (en) Process for producing desulfurizing agents for pig iron or steel melts
EP0031552B1 (en) Desulphurising composition and process for its production
DE2037758C3 (en) Process for the production of calcium carbide for the desulfurization of metal melts
EP0061011B1 (en) Process for producing desulfurizing agents for pig iron or steel melts
EP0220522B1 (en) Mixture for desulfurizing metal melts, process for manufacturing it and its use
EP0019087B1 (en) Desulphurising agents for pig iron and steel melts, and process for their manufacture
DE2504026A1 (en) METALLURGICAL SCRAP AND SLAG TREATMENT METHOD
DE2708424C2 (en) Process for desulfurization of pig iron melts
DE69700665T2 (en) DESulphurizing calcium-carbide mixture
DE2709062A1 (en) MEANS AND METHODS FOR DESULFURIZING METAL IRON
DE2236160C3 (en) Means for desulphurizing liquid pig iron and process for its manufacture
DE898595C (en) Method of cleaning molten iron
EP0071101B1 (en) Process for the preparation of dust-proof fertilisers containing lime and phosphates
DE2952761A1 (en) Desulphurising of molten metals, esp. crude iron or steel - using mixed crystals of calcium carbide and calcium oxide which is partly hydrated
DE835613C (en) Cleaning agent for iron and steel melts
WO2016096178A1 (en) Mixture, use of said mixture and process for conditioning a slag located on a metal melt in a metallurgical vessel in iron and steel metallurgy
WO1999009224A1 (en) Method and equipment for processing iron- or oil-containing metallurgical waste
DE3310329C2 (en)
WO2001042159A1 (en) Method for crushing slack with simultaneous desulphurisation and subsequent dechroming
DE908378C (en) Process for treating metallurgical slag
DE2705543A1 (en) PROCESS FOR GENERATING SLAGS WITH INCREASED SOLUBLE PHOSPHATE CONTENT

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

17P Request for examination filed

Effective date: 19821127

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: KRUPP STAHL AKTIENGESELLSCHAFT

Owner name: HOECHST AKTIENGESELLSCHAFT

ITF It: translation for a ep patent filed
GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

REF Corresponds to:

Ref document number: 9596

Country of ref document: AT

Date of ref document: 19841015

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3260809

Country of ref document: DE

Date of ref document: 19841031

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19900423

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19910125

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19910128

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: LU

Payment date: 19910130

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19910214

Year of fee payment: 10

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19910228

Ref country code: CH

Effective date: 19910228

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19910228

Year of fee payment: 10

EPTA Lu: last paid annual fee
REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19920115

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 19920122

Year of fee payment: 11

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19920225

Ref country code: GB

Effective date: 19920225

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19920226

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Effective date: 19920228

ITTA It: last paid annual fee
BERE Be: lapsed

Owner name: HOECHST A.G.

Effective date: 19920228

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19920901

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Effective date: 19930225

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19931029

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

EUG Se: european patent has lapsed

Ref document number: 82101427.1

Effective date: 19920904

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19980123

Year of fee payment: 17

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19991201