US3820767A - Apparatus for the treatment of molten metal - Google Patents

Apparatus for the treatment of molten metal Download PDF

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Publication number
US3820767A
US3820767A US00222842A US22284272A US3820767A US 3820767 A US3820767 A US 3820767A US 00222842 A US00222842 A US 00222842A US 22284272 A US22284272 A US 22284272A US 3820767 A US3820767 A US 3820767A
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molten metal
cell
tubes
bath
treatment
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US00222842A
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English (en)
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P Metz
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Arcelor Luxembourg SA
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Arbed SA
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/10—Handling in a vacuum

Definitions

  • the means for introducing thereactive substance or the alloying ingredient material include a lance for injecting the treatment material below the level of the bath and beneath any slag layer overlying same, can include means for charging the treatment substance into a moving stream of the molten metal, e.g., as it is introduced into the receptacle, or may simply deposit or blow the treatment substance onto the top of the melt.
  • a lance for injecting the treatment material below the level of the bath and beneath any slag layer overlying same
  • the means for introducing thereactive substance or the alloying ingredient material include a lance for injecting the treatment material below the level of the bath and beneath any slag layer overlying same, can include means for charging the treatment substance into a moving stream of the molten metal, e.g., as it is introduced into the receptacle, or may simply deposit or blow the treatment substance onto the top of the melt.
  • it 4has been proposed to agitate the melt either with mechanical stirrers or by oscillation, electrical inductive stirring,
  • the treatment of molten metals has been handicapped by the presence of the slag layer upon theibath, by the inability to aboid entrainment of a portion of the slag into the body of the melt during treatment, and by difficulties with respect to distribution of the treatment agent throughout themelt.
  • Still another object of the invention is to provide an apparatus for treating molten metal with a minimum of expense and with maximum efficiency.
  • the withdrawn portion of the molten metal is lifted by a gas-lift pump or the like, preferably by injecting into the molten metal beneath an upright tube, a mass of small gas bubbles to create an emulsion of the molten metal of relatively low density, the low-density gas/metal emulsion rising autogenously in the upright tube to the treatment vessel in which a certain quantity of the metal can be maintained during circulation.
  • the gas separates from the molten metal within this vessel to increase the density of the treated portion which descends through a further upright tube to return to the bath below the slag layer or dross overlying same.
  • the molten metal of the bath to be treated may be contained in any of the usual receptacles, e.g., ladle, Crucible, converter or furnace,
  • the treatmentapparatus thus comprises a vessel having a volume determined by the desired quantity of metal retained or stored in the treatment cell along the recirculating path and a apir of tubes depending from this cell and opening into thebottom thereof.
  • Optimum circulation and distribution of the treated molten metal within the bath has been obtained with a system in which one of the tubes extends to a lower level within the bath than the other.
  • Preferably the riser tube extends further into the bath than the return tube.
  • the treatment of the molten metal within the cell -or treatment vessel is effected under atmospheric pressure, i.e., the treatment ⁇ vessel is Inot sealed above the molten metal therein from the atmosphere to the extent that a pressure different from that of atmosphere pressure is applied to the molten metal. within the treatment vessel.
  • the treatment vessel such that the base of its cell, inclined downwardly toward the return tube, lies above the surface of the metal or slag in the bath ⁇ to be treated, although less heating is required where the base of the treatment vessel is immersed in the bath, i.e., the major part of the metal to be treated and lying within the treatment cell, is disposed beneath the level of the bath from which the molten metal is withdrawn, although segregated therefrom by the wall of the treatment vessel.
  • I may provide means for raising and lowering the treatment vessel relative to the ladle or other receptacle for the molten-metal bath, for raising and lowering the latter receptacle, or for applying a subatmospheric pressure to the top of the bath of the receptacle to control thereby the position of the surface of the treated melt within the treatment vessel.
  • the major advantage of the present invention is that it allows a treatment of the molten metal in the bath free from entrainment of slag and contamination thereby, while permitting the slag layer to overlie the molten metal of the principal bath. Furthermore, the treatment may be effected at any given time with a relatively small quantity of molten metal so that, if it is necessaryv to avoid a fall in temperature of the treated metal, the additional heat applied to the latter during treatment may be minimal.
  • the treatment vessel with its descending tubes is inserted into the receptacle containing the bath to be treated, the tubes penetrating belowl and through the slag layer and being so provided as to prevent the introduction of slag into these tubes.
  • the mouth of the tubes may be covered with consumable members or may be maintained under pressure to exclude the introduction of slag as the vessel is lowered into the receptacle.
  • the circulation of the treated metal free from slag improvesthe homogeneity of distribution of the treatment agent throughout the body of the melt and eliminates the need for mechanical agitators.
  • the interaction of the treating agent with the circulated portion of the melt moreover, provides a constantly renewed surface contact between the additive into the molten metal.
  • the treatment portion of the metl is returned to the body of the latter well within the interior and without interference or with the slag.
  • any of the metallurgical additives introduced into the steel melt 'or a cast-iron melt may be used according to the invention and I may mention carbon, alloying ingredients such as nickel, chromium, cobalt, manganese, tungsten, and reactive ingredients such as aluminum, manganese and compounds thereof.
  • the additives maybe applied in powder or granular form, or even as consumable electrodes which may penetrate into the treated portion of the melt and are decomposed by the passage of an electric current therethrough.
  • the electroheating afforded in this manner may supply the sole additional heat required at the metal through the treatment vessel and no other flowcontrol means is required, e.g., at the return pump, I may provide an electromagnetic or induction apparatus to increase the circulating rate or augment the gas lift.
  • FIG. l is a diagrammatic vertical cross-sectional view through a metallurgical treatment apparatus according to the invention.
  • FIG. 2 is a vertical cross-sectional view similar to FIG. 1, but illustrating another embodiment of the invention
  • FIG. 3 is an enlarged axial cross-sectional view representing a detail of a tube of FIG. l or FIG. 2 as it is introduced into the molten-metal bath;
  • FIG. 4 is a fragmentary, axial, cross-sectional view showing another upright tube according to the invention.
  • FIG. 5 is a diagrammaric cross-section illustrating other features of the invention.
  • FIG. 6 is a fragmentary cross-sectional view showing still another feature of the invention.
  • FIG. 7 is a somewhat perspective view showing the gas-injector of a gas-lift pump according to the invention.
  • FIG. l of the drawing I have shown a ladle or other metal-bath receptacle 5 containing a bath l1 of molten metal, e.g. steel or cast iron, which is to be treated.
  • the main bath of molten metal is overlain by a slag or dross layer l2 which generally interferes with the introduction of additives to the melt from above in conventional systems.
  • a treatment vessel represented generally at 1 and comprising an upwardly open cell 1', the bottom 1" of which is located below the level l2 of the molten substances within the receptacle 5 so that loss of heat is low.
  • the treatment vessel 1 is provided with two upright tubes 2 and 3 which depend from the cell 1' in spaced-apart parallel relationship, the mouth 3 of tube 3 terminating above the mouth 2' of tube 2 by a distance D ensuring the circulation of a portion of molten metal as well .as distribution thereof is represented by the arrows.
  • the riser tube 2 is located directly above and registers with an injector 4 of gas under pressure, the injector being constituted as a hollow ceramic body provided with closely spaced apertures from which small bubbles of gas are dispensed upwardly to form an emulsion rising in tube 2 and separating in the cell l' into a gas phase 4 and the molten metal 411.
  • the gas is employed for this purpose, is preferably any inert or reducing gas.
  • the treatment agent can be cast directly onto the surface of the metal 1l within the vessel 1, e.g., from a hopper 9, in accordance with conventional techniques.
  • each tube e.g., as shown for the tube 102 in FIG. 3, is provided with a consumable cap 120 of sheet metal or cardboard.
  • the cover prevents vthe slag from penetrating into the tube but rapidly melts away or is burned up to leave the mouth of the tube free for treatment.
  • the low density of the gas/metal emulsion within tube 2 produces an upward or buoyancy force causing the molten metal to rise into the vessel 1 to a level determined by the gas-flow rate and the cross-sections of tubes 2 and 3, this level being slightly above the level of the bath 1l, 12 when both the surface of the bath and the surface of the melt within vessel l are at atmospheric pressure.
  • the treated metal whose density is greater than that of the emulsion rising in column 2, returns to the bath through tube 3 and is distributed ⁇ within the latter.
  • the injector 4 is spaced below the mouth of tube 2 and may be inserted in the bath as described in FIG. l or permanently mounted in the floor of the receptacle (FIG. 2) or can be formed directly on the vessel 1. y i
  • the treatment vessel 201 is shown to comprise a cell 201' disposed well above the level of the ⁇ slag layer 212 and the molten metal 211 within the receptacle 205.
  • the receptacle 205 is closed hermetically by a cover 206 and is charged, above the level of the melt therein, via a duct 208, with a gas under pressure, causing the molten metal 211' to ride up into the cell-201 and enabling the molten metal 211' to ride up into the cell 201' and enabling the molten metal to be supported there.
  • the upper surface of the treated portion of the metal is exposed to atmospheric pressure..
  • gas injector 204 produces an emulsion of the molten metal which rises in tube 202, separates in cell 201 and gives rise to a more dense stream which descends in tube 203.
  • a duct 207 supplies gas to the injector 204.
  • I may increase the flow rate by the electromotor effect of an electromagnetic pump, here shown as an induction coil 223 surrounding the tube 202 and energized by an induction-current source 224.
  • the electromagnetic pump in this case works together with the gas-lift pump to circulate the molten metal.
  • the pressurization of the surface of the melt 211, 212 allows adjustment'of the quantity of metal maintained within the cell 201 without regulating the effective cross-section ofthe tube 203 and independent of the circulating rate of the gas-lift pump.
  • the homogeneity of the distribution of the circulating stream of metal intothe body of the melt and the homogenization of the molten metal within the treatment vessel l, 201 can be increased by varying the level of the bath in the receptable 5, 205 and/or in the treatment vessel l, 201.
  • This variation in level i.e., rise and drop in the surface, can be produced lin the system of FIG. 2 by pulsing a valve 22S between the pressure source 226 of duct 208 and the receptacle 205.
  • the pulser eg., a timer 227 is employed to trigger the valve.
  • the treatment agent may be introduced via the dosing and feed device 209 while the burner 210 is provided to heat the circulating stream of molten metal within the vessel 201.
  • the molten-metal level may be varied by modifying the rate of flow of gas to the injector.
  • FIG. 5 for example, there is shown an arrangement in which the injector 304 is supplied with the inert or reducing gas by a pump 330 through a valve 331 which is pulsed by a timer or pulser 332.
  • the pule period may range from 0.1 second to l minute, the gas on time being generally between and 90% of the pulse period.
  • the pulsing and/or gas injection to circulate the molten metal is, in any event, maintained subsequent to termination of the addition of the alloying ingredients or reagents, for a period sufficient to ensure complete distribution of the treated metal within the main body of the melt.
  • This latter period should be sufficient for at least one complete circulation of molten metal within the ladle.
  • the circulation should be maintained for a minimum of 25 minutes after termination of the treatment or where the circulation rate is 25 tons/minute, the post-treatment period can be about l minute.
  • the surface of the molten metal 311l within the treatment vessel 301 can be covered with a protective slag layer 312 which remains in place during circulation.
  • This slag which may be an electroslag remelting flux, can conduct electric current between a pair of electrodes 333 conducted to an electric current source 344 to supply the additional heat necessary for electroslag heating this temperature may be well above the melt temperature.
  • the level of the melt in the latter and in the receptacle 305 may be adjusted by raising or lowering-the vessel 301, e.g., via a motor 335 at the frequency produced by the pulser 332.
  • the ladle 305 itself may be suspended from a winch arrangement 336 which is likewise pulsed as may be the gas supply 308 to the receptacle 305.
  • the additives may be provided, moreover, in the form of granules or powder blown from a hopper 309 into the bath through the injector 304 at the base of the riser tube 302. In this case, the additives are supplied in suspension in the gas of the pumping arrangement.
  • another method of incorporating the additive into the molten metal 411' within the vessel 401 is to constitute such material as Aconsumable electrodes 409 and decompose these electrodes while heating the circulating stream.
  • Induction heating can be provided, e.g., at the same time as electromagnetic pumping, as described in connection with FIG. 4, or resistive heating elements may be incorporated in the vessel l, 201, 301, etc.
  • the heating of the treated metal stream often suffices in the case of steel melts so that reheating of the latter may not be necessary.
  • the introduction of substances with a low boiling point or sensitivity to oxidation may require the closing of the treatment vessel to prevent loss of treatment agent or to control noxious fumes which may be generated. This is the case when magnesium is to be incorporated in a melt in order to produce a metal containing spheroidal graphite or where lead or sulfur are to be introduced.
  • a treatment vessel comprising a treatment cell of a 10 relatively large horizontal cross-section adapted to receive a quant-ity of molten metal. to be treated, and a pair of upright tubes of horizontal crosssections smaller than that of said cell leading downwardly from said cell and terminating below said layer in said bath, both said tubes communicating with the interior of said cell and being immersed in said bath at spaced-apart locations within said receptacle;
  • said one of said tubes having a mouth opening into said bath at a location below the mouth of said other tube in said bath, said cell having a floor sloping downwardly from said one of said tubes toward said other of said tubes, said vessel being open to the atmosphere;

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
  • Manufacture And Refinement Of Metals (AREA)
US00222842A 1971-02-04 1972-02-02 Apparatus for the treatment of molten metal Expired - Lifetime US3820767A (en)

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Application Number Priority Date Filing Date Title
LU62545 1971-02-04

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US (1) US3820767A (en, 2012)
AT (1) AT340457B (en, 2012)
BE (1) BE778906A (en, 2012)
DE (1) DE2205090A1 (en, 2012)
FR (1) FR2124426B1 (en, 2012)
GB (1) GB1368881A (en, 2012)
IT (1) IT948437B (en, 2012)
LU (1) LU62545A1 (en, 2012)
NL (1) NL7201418A (en, 2012)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3932173A (en) * 1972-09-27 1976-01-13 Allmanna Svenska Elektriska Aktiebolaget Inductially heated gas lift pump action method for melt reduction
US3971655A (en) * 1974-08-21 1976-07-27 Nippon Steel Corporation Method for treatment of molten steel in a ladle
US4236917A (en) * 1978-07-21 1980-12-02 Dolzhenkov Boris S Method of gas-dynamic stirring of liquid molten metals and apparatus for performing same
US4544405A (en) * 1983-09-02 1985-10-01 M.A.N. Maschinenfabrik Augsburg-Nurnberg Aktiengesellschaft Method of producing steels of great purity and low gas content in steel mills and steel foundries and apparatus therefor
US5603749A (en) * 1995-03-07 1997-02-18 Bethlehem Steel Corporation Apparatus and method for vacuum treating molten steel
US6162388A (en) * 1997-12-22 2000-12-19 Sollac Metallurgical reactor for the treatment under reduced pressure of a liquid metal
WO2016182605A1 (en) * 2015-05-09 2016-11-17 Brilliant Light Power, Inc. Thermophotovoltaic electrical power generator
CN109247031A (zh) * 2016-01-19 2019-01-18 辉光能源公司 热光伏发电机
US10399405B2 (en) 2015-04-22 2019-09-03 Raizer Enterprises, Llc Trailer with height-adjusting axle assembly
US11230776B2 (en) 2014-05-29 2022-01-25 Brilliant Light Power, Inc. Electrical power generation systems and methods regarding same

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2204692A1 (en) * 1972-10-31 1974-05-24 Arbed Making addns to steel melts - in ladles without slag contamination
EP0000466A1 (de) * 1977-07-13 1979-02-07 VOEST-ALPINE Aktiengesellschaft Verfahren zum Einbringen von körnigen Stoffen in eine Metallschmelze und Vorrichtung zur Durchführung des Verfahrens
FR2433583A1 (fr) * 1978-08-18 1980-03-14 Nippon Steel Corp Cuve de prelevement de metal d'un bain de metal fondu, pour son traitement
USRE31676E (en) 1982-09-29 1984-09-18 Thyssen Aktiengesellschaft vorm August Thyssen-Hutte AG Method and apparatus for dispensing a fluidizable solid from a pressure vessel

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1492043A (fr) * 1966-02-18 1967-08-18 Purmetall Werner Funke Fa Séparateur de scories pour une installation de dégazage par le vide

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3932173A (en) * 1972-09-27 1976-01-13 Allmanna Svenska Elektriska Aktiebolaget Inductially heated gas lift pump action method for melt reduction
US3971655A (en) * 1974-08-21 1976-07-27 Nippon Steel Corporation Method for treatment of molten steel in a ladle
US4236917A (en) * 1978-07-21 1980-12-02 Dolzhenkov Boris S Method of gas-dynamic stirring of liquid molten metals and apparatus for performing same
US4544405A (en) * 1983-09-02 1985-10-01 M.A.N. Maschinenfabrik Augsburg-Nurnberg Aktiengesellschaft Method of producing steels of great purity and low gas content in steel mills and steel foundries and apparatus therefor
US5603749A (en) * 1995-03-07 1997-02-18 Bethlehem Steel Corporation Apparatus and method for vacuum treating molten steel
US6162388A (en) * 1997-12-22 2000-12-19 Sollac Metallurgical reactor for the treatment under reduced pressure of a liquid metal
US11885034B2 (en) 2014-05-29 2024-01-30 Brilliant Light Power, Inc. Electrical power generation systems and methods regarding same
US11230776B2 (en) 2014-05-29 2022-01-25 Brilliant Light Power, Inc. Electrical power generation systems and methods regarding same
US10399405B2 (en) 2015-04-22 2019-09-03 Raizer Enterprises, Llc Trailer with height-adjusting axle assembly
US11007836B2 (en) 2015-04-22 2021-05-18 Raizer Enterprises, Llc Trailer with height-adjusting axle assembly
JP2018524557A (ja) * 2015-05-09 2018-08-30 ブリリアント ライト パワー インコーポレーティド 熱光起電力発電装置
CN107710331B (zh) * 2015-05-09 2021-03-05 辉光能源公司 热光伏电力产生器
TWI725949B (zh) * 2015-05-09 2021-05-01 美商明亮光源能源公司 熱光伏打電力產生器
CN107710331A (zh) * 2015-05-09 2018-02-16 辉光能源公司 热光伏电力产生器
WO2016182605A1 (en) * 2015-05-09 2016-11-17 Brilliant Light Power, Inc. Thermophotovoltaic electrical power generator
TWI833071B (zh) * 2015-05-09 2024-02-21 美商明亮光源能源公司 使用熱光伏打電力產生器以產生電力之方法
CN109247031A (zh) * 2016-01-19 2019-01-18 辉光能源公司 热光伏发电机
CN109247031B (zh) * 2016-01-19 2023-02-17 辉光能源公司 热光伏发电机

Also Published As

Publication number Publication date
LU62545A1 (en, 2012) 1972-12-05
FR2124426B1 (en, 2012) 1974-06-28
BE778906A (en, 2012) 1972-05-30
GB1368881A (en) 1974-10-02
AT340457B (de) 1977-12-12
DE2205090A1 (de) 1972-09-21
IT948437B (it) 1973-05-30
ATA91672A (de) 1977-04-15
FR2124426A1 (en, 2012) 1972-09-22
NL7201418A (en, 2012) 1972-08-08

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