EP0338024B1 - Powder for continuous casting - Google Patents

Powder for continuous casting Download PDF

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Publication number
EP0338024B1
EP0338024B1 EP19880901755 EP88901755A EP0338024B1 EP 0338024 B1 EP0338024 B1 EP 0338024B1 EP 19880901755 EP19880901755 EP 19880901755 EP 88901755 A EP88901755 A EP 88901755A EP 0338024 B1 EP0338024 B1 EP 0338024B1
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Prior art keywords
granulated
powder
weight
process according
water
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German (de)
French (fr)
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EP0338024A1 (en
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Eva Maria Donati
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DIPL.-ING. BELA TISZA & CO. VORMALS MUEHLEN-INDUST
TISZA, EVA MARIA VEREHELICHTE DONATI
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Dipl-Ing Bela Tisza & Co Vormals Muehlen-Industrie fur Zerkleinerung und Aufbereitung Gesmbh
Tisza Eva Maria verehelichte Donati
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/10—Supplying or treating molten metal
    • B22D11/11—Treating the molten metal
    • B22D11/111—Treating the molten metal by using protecting powders

Definitions

  • the invention relates to a process for the production of granulated continuous casting powder which is suitable for the continuous casting of steels of all types and which permits the use of high casting speeds.
  • the previously known methods for producing granulated casting powder are based on slurrying the casting powder components in water, at least 30% of water being required, whereupon this suspension is then sprayed or atomized or extruded in order to obtain a granulate which is then dried.
  • this suspension is then sprayed or atomized or extruded in order to obtain a granulate which is then dried.
  • open, spherical hollow bodies or closed, cylindrical full bodies are obtained.
  • DE-OS 35 37 281 describes a process for the production of casting powder for casting steel, in which it is pointed out as an essential measure that some of the reactions which take place when the powder is melted are already present is shifted into the manufacturing process.
  • the mixture components must be comminuted and mixed together in an aqueous phase, after which the resulting suspension is dried and granulated in a fluidized bed.
  • the shape of the granules is subject to various requirements:
  • the granulate should be easy to convey both pneumatically and mechanically, and the grain should not be broken. There must be no abrasion, because dust can interfere with the automatic measuring and dosing devices for charging the mold with mold powder and its level regulation on the bath level. Furthermore, the granules should be distributed well on the liquid bath level in the mold so that the liquid steel is well covered.
  • the granules produced by the previously known processes have disadvantages in this regard.
  • the hollow spheres have insufficient mechanical strength, while the cylindrical bodies are poorly distributed on the liquid steel in the mold.
  • the invention is therefore based on the object of specifying a process for producing a granulated continuous casting powder which not only satisfies the requirements for rapid melting at the interface between the liquid jet and casting powder and for high thermal insulation of the applied casting powder layer, but also sufficient mechanical strength has to be able to be conveyed without breaking, and moreover is as spherical as possible to ensure a good distribution when using the powder.
  • granules within certain sizes should be producible with such a method, the granules should have the lowest possible bulk density, the powder mixture must not separate or change in its chemical analysis as a result of the granulation process, the investment and energy costs of the production should be low and finally If possible, all powder mixtures should be able to be processed into granules with a single system.
  • these objectives are achieved by a process for the production of granulated continuous casting powder based on high-melting oxides, such as silicon dioxide, calcium oxide or a calcium oxide-producing product, fluxes, such as alkali metal carbonates or calcium fluoride, and a carbon carrier which is characterized in that the dry powder Starting components with the addition of water, an inorganic granulating agent and optionally an organic binder are granulated in a centrifugal or vortex mixer to give spherical, full geranules.
  • high-melting oxides such as silicon dioxide, calcium oxide or a calcium oxide-producing product
  • fluxes such as alkali metal carbonates or calcium fluoride
  • a carbon carrier which is characterized in that the dry powder
  • an inorganic granulating agent and optionally an organic binder are granulated in a centrifugal or vortex mixer to give spherical, full geranules.
  • the granulated full casting powder produced according to the invention is in spherical form, it has a high fluidity and can be distributed very well on the liquid level in the casting mold. Due to its high mechanical strength, there is no abrasion during conveying and mold loading, which means that workplace-related and ecological problems can be avoided as well as malfunctions in the automatic measuring and dosing devices. It has proven particularly advantageous that the process according to the invention requires only small amounts of water to granulate the powder. This saves considerable amounts of energy during the subsequent drying process.
  • a powder mixture based on high-melting oxides, fluxes and carbon carriers is expediently granulated in a mixer which works by a centrifugal or whirling process, with the addition of inorganic granulating agent and water.
  • a very low content of inorganic granulating agent of up to about 1% by weight and a very low water content of about 10 to 15% by weight are sufficient.
  • a particularly suitable inorganic granulating agent is a colloidal dispersion of amorphous silicon dioxide in water, for example a 30% silica sol.
  • the silicon dioxide is present in the form of spherical individual particles which are not cross-linked with one another and which are hydrolyzed on the surface.
  • the sol changes to the gel state, i.e. in solid amorphous, water-insoluble silicon dioxide, binding the casting powder components to a solid, full granulate.
  • Water glass for example, can also be used as the inorganic granulating agent.
  • the granulated, spherical continuous casting powder is dried after the granulation process, expediently in a fluid bed dryer to a residual moisture content of less than 1% by weight, with an inlet air temperature from 120 to 180 ° C, for example.
  • the continuous casting powder is expediently granulated to a grain size of approximately 200 ⁇ m to more than 1 mm, different grain size distributions being obtained depending on the type of mixing.
  • the granulated continuous casting powder produced according to the invention can be used without any dust formation in steelworks in which fully automatic devices carry out a pneumatic or mechanical metering of continuous casting powder in continuous casting plants.
  • the components are mixed in a ploughshare mixer for 2 minutes. Then 15% water with a silica content of 4.3%, corresponding to an absolute content of 0.65% silica, is added. After a granulation time of 19 minutes and a drying time of 4 minutes in a hard-bed dryer, the following grain yield is obtained under the following conditions: Dryer, air inlet temperature 160 ° C Granulated casting powder, residual moisture 0.3% Grain analysis:
  • a granulate is prepared in the following way:
  • the residual moisture of the granules is 0.2%, the bulk density is 0.905 kg / m3.
  • the grain analysis of the starting mixture shows:
  • the components are granulated for 7 minutes in a ploughshare mixer with 11.7% moisture (including 1.2 colloidal silica). After drying in a fluid bed dryer with a hot air inlet of 140 ° C and a residence time of 3 minutes, granules with a residual moisture of 0.3%, a bulk density of 0.90 kg / m3 and a grain size of

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
  • Silicon Compounds (AREA)
  • Glanulating (AREA)

Abstract

In a process for producing granulated powder for continuous casting on the basis of refractory oxides, such as silicon dioxide, calcium oxide or a product giving off calcium oxide, of flux powders such as alkali carbonates or calcium fluoride, and of a carbonaceous medium, the powder mix is granulated into spherical, solid granules by the admixture of water, an anorganic granulating agent and if necessary an organic binder.

Description

Die Erfindung bezieht sich auf ein Verfahren zur Herstellung von granuliertem Stranggießpulver, das sich zum Stranggießen von Stählen aller Art eignet und die Anwendung hoher Gießgeschwindigkeiten erlaubt.The invention relates to a process for the production of granulated continuous casting powder which is suitable for the continuous casting of steels of all types and which permits the use of high casting speeds.

Beim Stranggießen von Stahl wird u.a. angestrebt, durch den Einsatz verbesserter Stranggießpulver die Gießgeschwindigkeit erhöhen zu können, und durch Automatisierung von Verfahrensabläufen eine Kostenreduktion zu erzielen.When casting steel continuously, strived to be able to increase the casting speed by using improved continuous casting powder, and to achieve a cost reduction by automating process sequences.

Für das Stranggießen von Stahl sind bereits zahlreiche verschiedene Gießpulver vorgeschlagen worden, siehe hiezu beispielsweise die in der AT-PS 342 800 und in der DE-OS 34 03 279 beschriebenen losen Gießpulver und das in der DE-OS 26 14 957 angeführte, in Form von Hohlkugeln vorliegende Stranggießpulver mit einer Korngröße von über 60 µm. Granulierte Pulver sind homogener, sie entmischen sich nicht bei Verpackung und Transport, verursachen weniger Staub und können besser durch automatische Geräte auf die Gießkokille dosiert werden.Numerous different casting powders have already been proposed for the continuous casting of steel, see for example the loose casting powder described in AT-PS 342 800 and in DE-OS 34 03 279 and the one mentioned in DE-OS 26 14 957 in the form Continuous casting powder of hollow spheres with a grain size of more than 60 µm. Granulated powders are more homogeneous, they do not separate during packaging and transport, cause less dust and can be better dosed onto the casting mold by automatic devices.

Die bisher bekannten Verfahren zur Herstellung von granuliertem Gießpulver beruhen auf einem Aufschlämmen der Gießpulverkomponenten in Wasser, wobei mindestens 30% Wasser benötigt werden, worauf diese Suspension dann versprüht oder verdüst oder extrudiert wird, um zu einem Granulat zu gelangen, welches abschließend getrocknet wird. Je nach dem angewendeten Verfahren erhält man offene, kugelförmige Hohlkörper oder aber geschlossene, zylinderförmige volle Körper.The previously known methods for producing granulated casting powder are based on slurrying the casting powder components in water, at least 30% of water being required, whereupon this suspension is then sprayed or atomized or extruded in order to obtain a granulate which is then dried. Depending on the method used, open, spherical hollow bodies or closed, cylindrical full bodies are obtained.

So beschreibt die DE-OS 35 37 281 ein Verfahren zur Herstellung von Gießpulver zum Vergießen von Stahl, worin als wesentliche Maßnahme herausgestellt wird, daß ein Teil der beim Aufschmelzen des Pulvers ablaufenden Reaktionen bereits in den Herstellungsprozeß verlagert wird. Hiezu müsen die Gemischkomponenten gemeinsam in einer wäßrigen Phase zerkleinert und gemischt werden, wonach die entstandene Suspension in einer Wirbelschicht getrocknet und granuliert wird.For example, DE-OS 35 37 281 describes a process for the production of casting powder for casting steel, in which it is pointed out as an essential measure that some of the reactions which take place when the powder is melted are already present is shifted into the manufacturing process. For this purpose, the mixture components must be comminuted and mixed together in an aqueous phase, after which the resulting suspension is dried and granulated in a fluidized bed.

Von der Form her werden an die Granulate verschiedene Forderungen gestellt:The shape of the granules is subject to various requirements:

Das Granulat soll sich pneumatisch wie auch mecanisch gut fördern lassen, es soll dabei das Korn nicht gebrochen werden. Es darf kein Abrieb entstehen, weil Staub die automatische Meß- und Dosiereinrichtungen für die Beschickung der Kokille mit Gießpulvergranulat und dessen Niveauregulierung auf dem Badspiegel stören kann. Weiterhin soll sich das Granulat am flüssigen Badspiegel in der Kokille gut verteilen, damit der flüssige Stahl gut abgedeckt wird.The granulate should be easy to convey both pneumatically and mechanically, and the grain should not be broken. There must be no abrasion, because dust can interfere with the automatic measuring and dosing devices for charging the mold with mold powder and its level regulation on the bath level. Furthermore, the granules should be distributed well on the liquid bath level in the mold so that the liquid steel is well covered.

Die nach den bisher bekannten Verfahren hergestellten Granulate haben in dieser Hinsicht Nachteile. Die Hohlkugeln weisen eine ungenügende mecanische Festigkeit auf, während die zylinderförmigen Körper sich schlecht am flüssigen Stahl in der Kokille verteilen.The granules produced by the previously known processes have disadvantages in this regard. The hollow spheres have insufficient mechanical strength, while the cylindrical bodies are poorly distributed on the liquid steel in the mold.

Der Erfindung liegt daher die Aufgabe zugrunde, ein Verfahren zur Herstellung eine granulierten Stranggießpulvers anzugeben, das nicht nur den Forderungen nach einem schnellen Aufschmelzen an der Grenzfläche zwischen flüssigem Strahl und Gießpulver und nach einer hohen Wärmedämmung der aufgebrachten Gießpulverschicht genügt, sondern darüberhinaus eine ausreichende mechanische Festigkeit aufweist, um ohne brechen gefördert werden zu können, und überdies möglichst kugelförmig ist, um eine gute Verteilung beim Einsatz der Pulver zu gewährleisten. Weiterhin sollen mit einem solchen Verfahren Granulate innerhalb bestimmter Größen herstellbar sein, die Granulate sollen ein möglichst niedriges Schüttgewicht haben, das Pulvergemisch darf sich durch den Granuliervorgang nicht entmischen oder in seiner chemischen Analyse verändern, die Investitions- und Energiekosten der Herstellung sollen niedrig sein und schließlich sollen sich möglichst alle Pulvergemische mit einer einzigen Anlage zu Granulaten verarbeiten lassen.The invention is therefore based on the object of specifying a process for producing a granulated continuous casting powder which not only satisfies the requirements for rapid melting at the interface between the liquid jet and casting powder and for high thermal insulation of the applied casting powder layer, but also sufficient mechanical strength has to be able to be conveyed without breaking, and moreover is as spherical as possible to ensure a good distribution when using the powder. Furthermore, granules within certain sizes should be producible with such a method, the granules should have the lowest possible bulk density, the powder mixture must not separate or change in its chemical analysis as a result of the granulation process, the investment and energy costs of the production should be low and finally If possible, all powder mixtures should be able to be processed into granules with a single system.

Diese Ziele werden erfindungsgemäß durch ein Verfahren zur Herstellung von granuliertem Stranggießpulver auf der Basis von hochschmelzenden Oxiden, wie Siliziumdioxid, Calciumoxid bzw. eines Calciumoxid liefernden Produktes, von Flußmitteln, wie Alkalicarbonaten bzw. Calciumfluorid, und eines Kohlenstoffträgers erreicht, das sich dadurch auszeichnet, daß die trockenen pulverförmigen Ausgangskomponenten unter Zugabe von Wasser, eines anorganischen Granuliermittels und gegebenenfalls eines organischen Binders in einem Schleuder- oder Wirbelmischer zu kugelförmigen, vollen Geranulaten granuliert werden.According to the invention, these objectives are achieved by a process for the production of granulated continuous casting powder based on high-melting oxides, such as silicon dioxide, calcium oxide or a calcium oxide-producing product, fluxes, such as alkali metal carbonates or calcium fluoride, and a carbon carrier which is characterized in that the dry powder Starting components with the addition of water, an inorganic granulating agent and optionally an organic binder are granulated in a centrifugal or vortex mixer to give spherical, full geranules.

Dadurch, daß das erfindungsgemäß hergestellte granulierte volle Gießpulver in Kugelform vorliegt, weist es ein hohes Fließvermögen auf und läßt sich sehr gut auf dem Flüssigkeitsspiegel in der Gießkokille verteilen. Zufolge seiner hohen mechanischen Festigkeit entsteht bei der Förderung und Kokillenbeschickung kein Abrieb, wodurch arbeitsplatztechnische und ökologische Probleme ebenso vermieden werden können wie Störungen der automatischen Meß- und Dosiereinrichtungen. Als besonders vorteilhaft erweist sich, daß das erfindungdgemäße Verfahren nur geringe Mengen an Wasser benötigt, um das Pulver zu granulieren. Dadurch werden erhebliche Energiemengen bei der anschließenden Trocknung eingespart.Because the granulated full casting powder produced according to the invention is in spherical form, it has a high fluidity and can be distributed very well on the liquid level in the casting mold. Due to its high mechanical strength, there is no abrasion during conveying and mold loading, which means that workplace-related and ecological problems can be avoided as well as malfunctions in the automatic measuring and dosing devices. It has proven particularly advantageous that the process according to the invention requires only small amounts of water to granulate the powder. This saves considerable amounts of energy during the subsequent drying process.

In der praktischen Ausführung des erfindungsgemäßen Verfahrens wird ein Pulvergemisch auf der Basis von hochschmelzenden Oxiden, Flußmitteln und Kohlenstoffträger zweckmäßig in einem Mischer, welcher nach einem Schleuder- oder Wirbelverfahren arbeitet, unter Zugabe von anorganischem Granuliermittel und Wasser granuliert. Hiebei reicht ein sehr geringer Gehalt an anorganischem Granuliermittel von bis zu etwa 1 Gew.-%, sowie ein gleichfalls sehr niedriger Wassergehalt von etwa 10 bis 15 Gew.-% aus.In the practical implementation of the process according to the invention, a powder mixture based on high-melting oxides, fluxes and carbon carriers is expediently granulated in a mixer which works by a centrifugal or whirling process, with the addition of inorganic granulating agent and water. A very low content of inorganic granulating agent of up to about 1% by weight and a very low water content of about 10 to 15% by weight are sufficient.

Als anorganisches Granuliermittel eignet sich im besonderen Maße eine kolloidale Dispersion von amorphem Siliziumdioxid in Wasser, beispielsweise ein 30%iges Kieselsol. In dem Kieselsol liegt das Siliziumdioxid in Form von untereinander unvernetzten kugelförmigen Einzelpartikeln vor, die an der Oberfläche hydrolisiert sind. Bei der erfindungsgemäßen Anwendung geht das Sol in den Gelzustand über, d.h. in festes amorphes, wasserunlösliches Siliziumdioxid, unter Bindung der Gießpulverbestandteile zu einem festen, vollen Granulat. Als anorganisches Granuliermittel kann beispielweise auch Wasserglas verwendet werden.A particularly suitable inorganic granulating agent is a colloidal dispersion of amorphous silicon dioxide in water, for example a 30% silica sol. In the silica sol, the silicon dioxide is present in the form of spherical individual particles which are not cross-linked with one another and which are hydrolyzed on the surface. In the application according to the invention the sol changes to the gel state, i.e. in solid amorphous, water-insoluble silicon dioxide, binding the casting powder components to a solid, full granulate. Water glass, for example, can also be used as the inorganic granulating agent.

Das granulierte, kugelförmige Stranggießpulver wird nach dem Granuliervorgang getrocknet, zweckmäßig in einem Fließbettrockner auf eine Restfeuchte von unter 1 Gew.-%, wobei mit einer Eingangslufttemperatur von z.B. 120 bis 180°C gearbeitet werden kann.The granulated, spherical continuous casting powder is dried after the granulation process, expediently in a fluid bed dryer to a residual moisture content of less than 1% by weight, with an inlet air temperature from 120 to 180 ° C, for example.

Falls eine zuzätzliche Steigerung der mechanischen Festigkeit der Granulate erzielt werden soll, kann dem Pulvergemish vor dem Granulieren bis zu 2 Gew.-% organisches Bindemittel zugesetzt werden.If an additional increase in the mechanical strength of the granules is to be achieved, up to 2% by weight of organic binder can be added to the powder mixture before the granulation.

Zweckmäßig wird das Stranggießpulver auf eine Korngröße von etwa 200µm bis über 1mm granuliert, wobei in Abhängigkeit von der Mischart unterschiedliche Korngrößenverteilungen erhalten werden.The continuous casting powder is expediently granulated to a grain size of approximately 200 μm to more than 1 mm, different grain size distributions being obtained depending on the type of mixing.

Das erfindungsgemäß hergestellte granulierte Stranggießpulver kann ohne jegliche Staubbildung in Stahlwerken eingesetzt werden, in welchen vollautomatisch arbeitende Vorrichtungen eine pneumatische oder mechanische Dosierung von Stranggießpulver bei Stranggießanlagen vornhmen.The granulated continuous casting powder produced according to the invention can be used without any dust formation in steelworks in which fully automatic devices carry out a pneumatic or mechanical metering of continuous casting powder in continuous casting plants.

Die Erfindung wird an Hand der nachfolgenden Ausführungsbeispiele, ohne sie hierauf zu beschränken, weiter erläutert.The invention is further explained on the basis of the following exemplary embodiments, without being restricted thereto.

BIESPIEL 1:EXAMPLE 1:

Aus den folgenden Komponenten:
   Calciumaluminiumsilikat,
   Natriumcarbonat,
   Flußspat,
   Kunstharzbinder
   Siliziumdioxid,
   Graphit und
   Flugasche
entsprechend einer chemischen Analyse der Zusammensetzung von:

SiO₂
31,6%
CaO
28,4%
Al₂O₃
12,2%
Na₂O
1,7%
Fe₂O₃
6,1%
F
2,9%
C
15,0%
und mit der folgenden Kornanalyse:
Figure imgb0001
wird in folgender Weise ein Granulat bereitet:The following components:
Calcium aluminum silicate,
Sodium,
Fluorspar,
Synthetic resin binder
Silicon dioxide,
Graphite and
Fly ash
according to a chemical analysis of the composition of:
SiO₂
31.6%
CaO
28.4%
Al₂O₃
12.2%
Na₂O
1.7%
Fe₂O₃
6.1%
F
2.9%
C.
15.0%
and with the following grain analysis:
Figure imgb0001
a granulate is prepared in the following way:

Die Komponenten werden 2 Minuten in einem Pflugscharmischer gemischt. Dann werden 15% Wasser mit einem Kieselsolgehalt von 4,3%, entsprechend einem Absolutgehalt von 0,65% Kieselsaüre beigefügt. Nach einer Granulierzeit von 19 Minuten und einer Trocknungszeit von 4 Minuten in einem Fleißbetttrockner erhält man unter den nachfolgend angeführten Bedingungen folgende Kornausbeute:
Trockner, Lufteingangstermperatur 160°C
Granuliertes Straggießpulver Restfeuchte 0,3%
Kornanalyse:

Figure imgb0002
The components are mixed in a ploughshare mixer for 2 minutes. Then 15% water with a silica content of 4.3%, corresponding to an absolute content of 0.65% silica, is added. After a granulation time of 19 minutes and a drying time of 4 minutes in a hard-bed dryer, the following grain yield is obtained under the following conditions:
Dryer, air inlet temperature 160 ° C
Granulated casting powder, residual moisture 0.3%
Grain analysis:
Figure imgb0002

BEISPIEL 2:EXAMPLE 2:

Aus
   Calciumcarbonat,
   Siliziumdioxid,
   Graphit,
   Natriumcarbonat und
   Calciumfluorid,
entsprechend einer chemischen Analyse der Zusammensetzung von

SiO₂
33%
CaO
30,5%
Al₂O₃
0,5%
Na₂O
4,8%
Fe₂O₃
0,3%
F
7,6%
C
11,4%
und mit einer Körnung:
Figure imgb0003
 Out
Calcium carbonate,
Silicon dioxide,
Graphite,
Sodium carbonate and
Calcium fluoride,
according to a chemical analysis of the composition of
SiO₂
33%
CaO
30.5%
Al₂O₃
0.5%
Na₂O
4.8%
Fe₂O₃
0.3%
F
7.6%
C.
11.4%
and with a grit:
Figure imgb0003

wird in folgender Weise ein Granulat bereitet:a granulate is prepared in the following way:

Als Granulierflüssigkeit dient Wasserglas von 37° BE. Bei einer Feuchte von 12,6% werden in einem kontinuierlichen Pfugscharmischer die Komponenten granuliert. Die Trocknung erfolgt anschließend in einem Fließbetttrockner mit einer Verweilzeit von 1 Minute unter den folgenden Bedigungen:

Heißlufttemperatur
180°C
Produkttemperatur
102°C
Water glass of 37 ° BE serves as the granulating liquid. At a moisture content of 12.6%, the components are granulated in a continuous ploughshare mixer. The drying is then carried out in a fluid bed dryer with a residence time of 1 minute under the following conditions:
Hot air temperature
180 ° C
Product temperature
102 ° C

Man erhält ein Produkt mit der Körnung:

Figure imgb0004
A product with the grain size is obtained:
Figure imgb0004

Die Restfeuchte des Granulates liegt bei 0,2%, das Schüttgewicht beträgt 0,905 kg/m³.The residual moisture of the granules is 0.2%, the bulk density is 0.905 kg / m³.

BEISPIEL 3: EXAMPLE 3

Die folgenden Komponenten werden für 2 Minuten in einem Pflugscharmischer gemischt:
   Calciumcarbonat,
   Siliziumdioxid,
   Aluminiumsilikat,
   Flußspat,
   Natriumcarbonat und
   Graphit,
entsprechend einer chemischen Analyse der Zusammensetzung von:

SiO₂
30,7%
CaO
29,0%
Al₂O₃
3,0%
Na₂O
4,6%
F
6,9%
C
10,2%
Fe₂O₃
0,7%
The following components are mixed in a ploughshare mixer for 2 minutes:
Calcium carbonate,
Silicon dioxide,
Aluminum silicate,
Fluorspar,
Sodium carbonate and
Graphite,
according to a chemical analysis of the composition of:
SiO₂
30.7%
CaO
29.0%
Al₂O₃
3.0%
Na₂O
4.6%
F
6.9%
C.
10.2%
Fe₂O₃
0.7%

Die Kornanalyse des Ausgangsgemisches ergibt:

Figure imgb0005
The grain analysis of the starting mixture shows:
Figure imgb0005

Die Komponenten werden 7 Minuten lang in einem Pflugscharmischer mit 11,7% Feuchte (einschließlich1,2 kolloidale Kieselsäure) granuliert. Nach einer Trocknung im Fließbetttrockner bei einem Heißlufteintritt von 140°C und einer Verweilzeit von 3 Minuten erhält man ein Granulat mit einer Restfeuchte von 0,3%, einem Schüttgewicht von 0,90 kg/m³ und einer Kornung von

Figure imgb0006
The components are granulated for 7 minutes in a ploughshare mixer with 11.7% moisture (including 1.2 colloidal silica). After drying in a fluid bed dryer with a hot air inlet of 140 ° C and a residence time of 3 minutes, granules with a residual moisture of 0.3%, a bulk density of 0.90 kg / m³ and a grain size of
Figure imgb0006

Claims (5)

1. A process for preparing a granulated continuous-casting powder on the basis of high-melting point oxides such as silicon oxide, calcium oxide or a product that forms a calcium oxide, from flux agents such as alkali carbonates or calcium fluoride, and a carbon carrier, characterized in that the dry powdered starting components are granulated in a centrifugal or vortex mixer with the addition of water, an inorganic granulating agent and, optionally, an organic binder, to produce spherical, solid granulates.
2. A process according to claim 1, characterized in that the powdered starting components are granulated with the addition of up to approximately 1 % by weight of an inorganic granulating agent and of from 10 to 15 % by weight of water.
3. A process according to claim 1 or claim 2, characterized in that a colloidal dispersion of amorphous silicon dioxide is used as the granulating agent.
4. A process according to claim 1, characterized in that up to 2 % by weight of an organic synthetic resin binding agent is added to the powder mixture prior to granulation.
5. A process according to any one of claims 1 to 4, characterized in that the granulated powder is dried in a fluid-bed drier to a residual moisture content of less than 1 % by weight.
EP19880901755 1987-02-20 1988-02-19 Powder for continuous casting Expired - Lifetime EP0338024B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AT378/87 1987-02-20
AT0037887A AT394320B (en) 1987-02-20 1987-02-20 METHOD FOR PRODUCING GRANULATED CONTINUOUS POWDER

Publications (2)

Publication Number Publication Date
EP0338024A1 EP0338024A1 (en) 1989-10-25
EP0338024B1 true EP0338024B1 (en) 1992-07-29

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP19880901755 Expired - Lifetime EP0338024B1 (en) 1987-02-20 1988-02-19 Powder for continuous casting

Country Status (5)

Country Link
EP (1) EP0338024B1 (en)
AT (1) AT394320B (en)
CA (1) CA1305303C (en)
DE (1) DE3873316D1 (en)
WO (1) WO1988006066A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0673730B2 (en) * 1990-11-30 1994-09-21 品川白煉瓦株式会社 Exothermic mold powder for continuous casting
DE102004026443B3 (en) * 2004-05-29 2006-02-02 Stefanie Heller Insulating granules for high temperature applications
CN114105658B (en) * 2021-11-30 2023-02-28 河南通宇冶材集团有限公司 Carbon-free drainage agent and preparation method thereof

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1569926A (en) * 1967-03-31 1969-06-06
BE801930A (en) * 1972-07-06 1974-01-04 Degussa PROCESS FOR MANUFACTURING SHAPED BODIES USING MOLECULAR SIEVES
DE2345921A1 (en) * 1973-09-12 1975-03-20 Solint Consulting Establishmen Heat-insulating cover for molten metals - using a granular with the same compsn. as the lining of the vessel
AT342800B (en) * 1975-04-16 1978-04-25 Tisza Bela & Co CONTINUOUS POWDER
JPS51140830A (en) * 1975-05-30 1976-12-04 Nisshin Steel Co Ltd Additions for casting
JPS586590B2 (en) * 1975-06-18 1983-02-05 サカイカガクコウギヨウ カブシキガイシヤ Granular flux for casting
JPS53108033A (en) * 1977-03-03 1978-09-20 Nippon Chemical Ind Additive of mold for continuous casting
JPS5514865A (en) * 1978-07-19 1980-02-01 Nippon Steel Corp Powder for continuous casting of steel
DE2917763A1 (en) * 1979-05-02 1980-11-13 Wacker Chemie Gmbh POWDER FOR CONTINUOUSLY STEEL
JPS5827979B2 (en) * 1979-06-30 1983-06-13 新日本製鐵株式会社 Manufacturing method of granular powder for continuous steel casting
GB8325438D0 (en) * 1983-09-22 1983-10-26 Foseco Int Fluxes for casting metals
JPS60145234A (en) * 1984-01-09 1985-07-31 Nissan Motor Co Ltd Device for forming bore serration
JPS61123454A (en) * 1984-11-20 1986-06-11 Kawasaki Steel Corp Flux for continuous casting and its production
DE3537281A1 (en) * 1984-11-23 1986-08-21 VEB Bandstahlkombinat "Hermann Matern", DDR 1220 Eisenhüttenstadt Method for producing casting powder for casting steel

Also Published As

Publication number Publication date
ATA37887A (en) 1991-09-15
DE3873316D1 (en) 1992-09-03
EP0338024A1 (en) 1989-10-25
CA1305303C (en) 1992-07-21
WO1988006066A1 (en) 1988-08-25
AT394320B (en) 1992-03-10

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