EP0223722B1 - Verfahren und Vorrichtung zum Einblasen von pulverigen Zusätzen in den Strahl einer Metallschmelze unter vermindertem Druck - Google Patents

Verfahren und Vorrichtung zum Einblasen von pulverigen Zusätzen in den Strahl einer Metallschmelze unter vermindertem Druck Download PDF

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Publication number
EP0223722B1
EP0223722B1 EP86420253A EP86420253A EP0223722B1 EP 0223722 B1 EP0223722 B1 EP 0223722B1 EP 86420253 A EP86420253 A EP 86420253A EP 86420253 A EP86420253 A EP 86420253A EP 0223722 B1 EP0223722 B1 EP 0223722B1
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EP
European Patent Office
Prior art keywords
der
die
eine
oder
dab
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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
EP86420253A
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English (en)
French (fr)
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EP0223722A1 (de
Inventor
Charles Defrancq
Alain Ruckebusch
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Ferropem SAS
Original Assignee
Pechiney Electrometallurgie SAS
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Publication of EP0223722A1 publication Critical patent/EP0223722A1/de
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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
    • B22D1/00—Treatment of fused masses in the ladle or the supply runners before casting
    • 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
    • C21C1/10—Making spheroidal graphite cast-iron
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B21/00—Obtaining aluminium
    • C22B21/06—Obtaining aluminium refining
    • C22B21/066—Treatment of circulating aluminium, e.g. by filtration
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
    • C22B9/10—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals with refining or fluxing agents; Use of materials therefor, e.g. slagging or scorifying agents
    • C22B9/103—Methods of introduction of solid or liquid refining or fluxing agents

Definitions

  • the present invention relates to a device and a method for continuous injection, under low pressure and protected from air, of a powder additive into a stream of molten metal.
  • This pulverulent additive is directed by carrier gas into the jet of molten metal, this gas possibly creating a protective atmosphere.
  • the present invention applies particularly to the case where the additive must be added to the liquid metal in small proportion, in a very homogeneous manner and, for example, immediately before casting.
  • injections are generally carried out by means of a lance immersed in a pocket containing the molten metal, the pulverulent additive being entrained by a stream of inert gas under a pressure sufficient to counterbalance the hydrostatic pressure of the liquid metal. But this mode of injection is discontinuous.
  • the object of the present invention is a device for continuous and controlled introduction, into a stream of liquid metal, of a predetermined proportion of powdered additive, under pressure, out of direct contact with the atmosphere and, if necessary, under a protective atmosphere, with a yield close to 100% and, in all cases greater than 85%.
  • Another object of the same invention pst a method of introducing additive into a stream of liquid metal using the above device.
  • the device which has the general shape of an hourglass comprises an outer metal casing (1) and an inner lining (2) heat-insulating and refractory whose nature is adapted to the metal (or alloy) to be treated.
  • metal any molten metal product, not alloyed or alloyed, subjected to the injection of additive, and by “additive” any powdery product (whatever its nature and its effects on the metal) injected into the metal.
  • additive any powdery product (whatever its nature and its effects on the metal) injected into the metal.
  • the term "pulverulent product” is taken here in the sense of product in more or less fine powder and / or in small grains the size of which can reach several millimeters, the limit being fixed by the possibilities of entrainment of the product in a stream of gas at low pressure.
  • the device is provided, at its upper part, with an inlet (3) for the metal to be treated, and, at its lower part, in the case in FIG. 1, with a calibrated orifice (4) for leaving the treated metal. It has three separate compartments, but communicating with each other: an upper compartment (5) into which the metal to be treated comes either directly from a processing furnace or from a holding furnace, or from an intermediate storage pocket , a buffer compartment (6) which opens through the calibrated orifice (4) onto an intermediate storage container or onto a ladle and, finally, a treatment chamber (7), located in the upper part of the compartment- buffer (6).
  • the treatment chamber (7) communicates with the inlet compartment (5) which surmounts it by a calibrated inlet orifice (8) whose role will be explained below.
  • the powder additive is injected into the metal through the tube (9), in a stream of pressurized gas, which shatters on the sheet of liquid metal flowing in the central zone (10) of the treatment chamber.
  • a lateral duct (11) allows the evacuation to the atmosphere of the protective gas and of any reaction gases, smoke or grime, so that the reaction chamber remains at a pressure slightly higher than atmospheric pressure.
  • the stream of metal mixed with the pulverulent additive then flows into the buffer compartment (6) where the dissolution of the additive and the reactions between the metal and the additive are eventually completed.
  • the passage section of the outlet orifice (4) is determined, that is to say say in fact, the speed of exit of the metal from the buffer compartment (6) in such a way that this compartment (6) remains constantly filled with liquid metal up to a level at least equal to about half the height and, preferably , at least equal to about two-thirds of the height (level N1), without however exceeding a maximum level (N2) located lower than the lower orifice (11 B) for removing any dirt.
  • FIG. 2 shows schematically a particularly well suited device which essentially comprises a reservoir of powder additive (20), a feed screw (21) passing through the lower part (22) of the reservoir (20), a motor (23) at high speed regulated and variable ensuring by means of a reducer (24) the drive of the screw (21) whose flow rate in powder additive is proportional to the speed of rotation, and a supply (25) of dried and deoiled compressed air , or in neutral gas (for example nitrogen or argon) which drives the additive to the injector (26) which also acts as a non-return device, then to the introduction pipe (9), supplied with gas under pressure through the pipe (27).
  • the reservoir (20) has two probes for measuring the level of the powdery additive (28).
  • FIG. 3 represents, in vertical section, a first variant of the invention, according to which the device is placed directly on a casting mold (30) of which only the inlet is shown.
  • the calibrated outlet orifice is no longer arranged at the base of the lower compartment: it is included in the mold and it is constituted by the smallest cross section of the attack system (set of conduits bringing the metal from the inlet from the mold to the feed channels of the mold cavities) and, for example, in the figurative case, by the descent of the load (31) or by the attacks (32) of the parts to be molded.
  • FIG. 4 represents, in vertical section, a second variant according to which two injections suc stops of powdery additives in the liquid metal can be achieved by putting in series two buffer compartments, an intermediate (6A), a lower (6B), each having its own inlet (9) (9 ') of additives pulverulent, its orifices (11A) and (11 B) for evacuating gases and dirt and its treatment chamber (7) (7 '), and its calibrated inlet orifices (8) and (8').
  • FIG. 5 represents a third variant of the invention, consisting in the addition to the lower part of the buffer compartment (6) of a siphon (35) allowing total retention of the dross not discharged through the orifice (11 B ).
  • the siphon can be adapted as well to the case of FIG. 1 and, in this case, it is the calibrated orifice (4), disposed at the base of the buffer compartment (6) which governs the speed of exit of the metal, than in FIG. 5 where the buffer compartment (6) or (6B) does not have a calibrated outlet orifice. This role is then played by the outlet section (36) of the siphon which is, for this, suitably calibrated.
  • the maintenance of the metal level in the lower compartment (6) can, if necessary, be measured and, if necessary regulated, by placing a certain number of level probes (13) in the wall of this compartment and by controlling the speed. metal introduction into the upper compartment.
  • the flow rate of the powdery additive can be controlled by the flow rate of the liquid metal entering the reaction chamber through the calibrated orifice (8) from the measurement of the level in the upper compartment (5) by means probes (14) for example.
  • the drawing of the mixing chamber (7) is given as an example of embodiment and does not constitute a limitation of the invention.
  • Those skilled in the art can optimize this design according to the nature of the metal treated (reactivity, viscosity) and the nature of the additive (powder in more or less fine grains, more or less reactive) so as to create , for example, swirling effects or effects of dispersion of the metal current, for example by adapting the shape of the orifice (8) or by interposing an obstacle such as (15) on this current at the exit of the orifice (8) or by any other equivalent means.
  • the device, object of the invention can be produced in two parts, separated by a plane passing through the vertical axis AA and perpendicular to the tube (9) for arrival of the powdery product. , and which are maintained, during casting, in contiguous and tight relation by clamps or hydraulic cylinders, in known manner, according to the dimensions of the device.
  • An experimental treatment device was constructed, according to the invention, in accordance with the diagram in FIG. 1, for the treatment of nodulization of spheroidal graphite cast iron by addition of a ferrosilicomagnesium in small grains containing 5.7% of magnesium.
  • the entry compartment (5) has an inverted pyramid shape.
  • the entry section is 250 x 250 mm and the height hi from the orifice (8) to the top of the entry compartment (5) is 250 mm.
  • the orifice (8) has a section of 1200 mm2 of rectangular shape 10 x 120 mm.
  • the lower compartment is cylindrical with a diameter of 150 mm and a height h2 of 270 mm between the calibrated outlet hole (4) and the dirt discharge orifice (11 B).
  • the outlet orifice (4) has a diameter of 40 mm, that is to say a passage section of 1257 mm 2 , to be compared to the 1200 mm 2 of the orifice (8).
  • the ferrosilicomagnesium additive is injected through the tube (9) with a weight flow of 90 g / second.
  • the carrier gas used is nitrogen at a pressure of 0.06 MPa.
  • the flow rate of liquid pig iron is 10 kg / second, which corresponds to an addition of 0.9% by weight of FeSiMg to 5.7% of magnesium, ie 0.051% of Mg added.
  • the device is supplied with liquid iron by an induction furnace, the treated cast iron being recovered in a 500 kg receiving pocket placed under the treatment device.
  • the magnesium incorporation yield defined by the relation: is 87%.
  • a second experimental treatment device was constructed, according to the invention, in accordance with the diagram in FIG. 3, with a view to carrying out in a single operation the treatment of nodulization and inoculation of spheroidal graphite cast iron.
  • This device is placed directly on a mold made of furan sand.
  • the total weight of the poured cluster is 55 kg.
  • the casting has a minimum thickness of 5 mm.
  • the entry compartment (5) has an inverted pyramid shape.
  • the inlet section is 250 x 250 mm and the height of the opening to the top of the inlet compartment (5) is 250 mm.
  • the orifice (8) has a section of 600 mm 2 of rectangular shape 6 x 100 mm.
  • the lower compartment is cylindrical with a diameter of 150 mm and heights': tor of 220 mm between the laying plane (34) on the mold (30) and the discharge port of the dross (11 B).
  • the weight flow rate in the mold is of the order of 5 kg / sec. This flow rate is adjusted by giving the load lowering channel a calibrated section.
  • the treatment product is a mixed product comprising 95% of FeSiMg containing 5.7% of magnesium and 5% of an inoculating ferrosilicon containing, inter alia, 1% of Bismuth and 0.5% of Rare Earths, according to our French patent.
  • the mixed product with a particle size of 0.2 to 1 mm is injected through the tube (9) with a weight flow rate of 45 g / second, which corresponds to 0.049% of Mg added.
  • the casting has a perfectly nodular structure in a totally ferritic matrix free of carbides.
  • the Mg incorporation yield in this case is 85%.
  • the invention can also be applied to simultaneous treatments of nodulization and inoculation, as described in Example 2, for spheroidal graphite cast irons; the levels of additives required to obtain the correct characteristics for these cast irons are often 50% lower than conventional nodulization and bag inoculation processes.
  • the arrangement of the device allows the immediate introduction of the treated metal into the mold (s) (fig. 3) which limits the risk of the effect of certain volatile, oxidizable additives or fleeting action (germination) vanishing. ).
  • the device in its different variants, also allows the injection of a reactive gas or liquid, with or without associated transport of powdery additive, for example to produce degassing of aluminum by injection of a chloreazote mixture.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Continuous Casting (AREA)
  • Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Manufacture Of Metal Powder And Suspensions Thereof (AREA)

Claims (13)

1. A device for continuous injection under low pressure of a powdered additive into a stream of molten metal, comprising in succession, from the top to the bottom:
- a top compartment 5 for the admission of the molten metal,
- a treatment chamber 7 connected to the top compartment by a calibrated inlet orifice 8 and in which there opens, on the one hand, a tube 9 connected to a device for injection of powdered additive under gas pressure and, on the other hand, at least one conduit 11 for evacuation of gases, fumes and possible drosses,
- at least one buffer compartment 6 cooperating with a means for adjusting the discharge rate of the treated metal,
-,a means for collecting the treated metal.
2. A device according to Claim 1, characterised in that it comprises two buffer compartments which are superimposed in series, an intermediate compartment 6A and a lower compartment 68 each comprising a treatment chamber 7, 7', a calibrated inlet orifice 8, 8', and at least one conduit for evacuation of gases, fumes and drosses.
3. A device according to Claims 1 or 2, characterised in that the treatment chamber comprises two evacuation conduits, au upper conduit 11 A for gases and fumes and a lower conduit 11 B for the evacuation of drosses.
4. A device according to Claims 1, 2 or 3, charactersied in that it comprises, at the base of the bufer compartment 6 or lower compartment 6A a siphon 35 for retaining drosses.
5. A device according to any one of Claims 1 to 4, characterised in that the means for adjusting the discharge rate of the treated metal is constituted by a calibrated orifice arranged in the path of the treated metal.
6. A device according to Claim 5, characterised in that the calibrated orifice 4 is arranged at the base of the buffer compartment 6 or of the lower compartment 6A.
7. A device according to Claim 5, characterised in that the calibrated orifice is integrated with the means for collecting the treated metal.
8. A device according to Claim 5, characterised in that the calibrated orifice is integrated with the siphon 35.
9. A device according to any one of Claims 1 to 8, characterised in that it comprises means such as 13, 14 for measuring the level of molten metal in the lower compartment 6 and/or in the upper compartment 5.
10. A device according to Claim 9, characterised in that it comprises means for regulating the intake of molten metal into the upper compartment 5 relative to the level of molten metal in the lower compartment 6.
11. A device according to any one of Claims 1 to 10, characterised in that it is made up in two portions which are separated by a plane passing through the vertical axis perpendicular to the inlet orifice or orifices of the powdered additive or additives 9.
12. A method of continuous injection of a powdered additive into a stream of molten metal employing the device according to any one of Claims 1 to 11, characterised in that:
- the molten metal is introduced into the upper compartment 5 while adjusting the flow rate so as to keep the level between an optimum level N3 and a maximum level N4,
- the additive or additives of which the injection rate is adjusted so as to introduce a predetermined weight of additive per kg of metal to treat is or are injected into the mixing chamber or chambers 7, 7' through the tube or tubes 9, 9' in a stream of carrier gas under pressure,
- the level or levels in the buffer compartment or compartments 6, 6' is/are kept between the optimum level N1 and the maximum level N2 by acting on the rate of introduction of the metal into the upper compartment 5,
- the treated metal is collected at the outlet of the buffer compartment 6 or of the lower buffer compartment 6'.
13. Application of the device according to one of Claims 1 to 11 to the treatment of molten, ferrous or non-ferrous metals characterised in that a reactive gas, vapour or liquid is injected through the tube 9.
EP86420253A 1985-10-15 1986-10-15 Verfahren und Vorrichtung zum Einblasen von pulverigen Zusätzen in den Strahl einer Metallschmelze unter vermindertem Druck Expired EP0223722B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8515609 1985-10-15
FR8515609A FR2588571B1 (fr) 1985-10-15 1985-10-15 Dispositif et procede d'injection continue sous faible pression d'un additif pulverulent dans un courant de metal fondu

Publications (2)

Publication Number Publication Date
EP0223722A1 EP0223722A1 (de) 1987-05-27
EP0223722B1 true EP0223722B1 (de) 1989-02-08

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP86420253A Expired EP0223722B1 (de) 1985-10-15 1986-10-15 Verfahren und Vorrichtung zum Einblasen von pulverigen Zusätzen in den Strahl einer Metallschmelze unter vermindertem Druck

Country Status (5)

Country Link
US (1) US4723763A (de)
EP (1) EP0223722B1 (de)
JP (1) JPS62164839A (de)
DE (1) DE3662059D1 (de)
FR (1) FR2588571B1 (de)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH680270A5 (de) * 1990-01-05 1992-07-31 Fischer Ag Georg
GB9015832D0 (en) * 1990-07-19 1990-09-05 Osprey Metals Ltd Introducing means
FR2665854A1 (fr) * 1990-08-20 1992-02-21 Pechiney Electrometallurgie Dispositif d'introduction tardive d'alliage particulaire lors de la coulee d'un metal liquide.

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE872497C (de) * 1944-08-27 1953-04-02 Eisenwerke Gelsenkirchen Ag Verfahren und Vorrichtung zum Legieren von geschmolzenen Metallen miteinander
US2803533A (en) * 1954-05-03 1957-08-20 Union Carbide Corp Method of injecting fluidized powders for metallurgical treatment
US2997384A (en) * 1958-03-28 1961-08-22 Fischer Ag Georg Method of treating molten metal
US2997386A (en) * 1958-06-27 1961-08-22 Feichtinger Heinrich Process and apparatus for treating metal melts
CH445538A (de) * 1964-02-28 1967-10-31 Fischer Ag Georg Verfahren zum Zuführen von Reaktions- und/oder Legierungsstoffen in metallische Schmelzen und Vorrichtung zur Durchführung des Verfahrens
US3598383A (en) * 1969-01-14 1971-08-10 William H Moore Method and apparatus for incorporating additives in a melt
AT321340B (de) * 1969-07-29 1975-03-25 Voest Ag Vorrichtung zum Einbringen feinkörniger oder flüssiger Zuschlagstoffe in flüssige Metalle und Verfahren zur Herstellung von Gußeisen mit kugeliger Graphitstruktur
US4191563A (en) * 1976-03-08 1980-03-04 Ford Motor Company Continuous stream treatment of ductile iron
US4298377A (en) * 1979-12-03 1981-11-03 Union Carbide Corporation Vortex reactor and method for adding solids to molten metal therewith

Also Published As

Publication number Publication date
FR2588571B1 (fr) 1992-05-22
FR2588571A1 (fr) 1987-04-17
JPS62164839A (ja) 1987-07-21
JPH0351772B2 (de) 1991-08-07
DE3662059D1 (en) 1989-03-16
US4723763A (en) 1988-02-09
EP0223722A1 (de) 1987-05-27

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