US3771998A - Method and converter for refining pig iron - Google Patents

Method and converter for refining pig iron Download PDF

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Publication number
US3771998A
US3771998A US00821802A US3771998DA US3771998A US 3771998 A US3771998 A US 3771998A US 00821802 A US00821802 A US 00821802A US 3771998D A US3771998D A US 3771998DA US 3771998 A US3771998 A US 3771998A
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United States
Prior art keywords
converter
oxygen
melt
lime
phosphorus
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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 - Lifetime
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US00821802A
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English (en)
Inventor
H Knuppel
K Brotzmann
H Fassbinder
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.)
Kloeckner CRA Technologie GmbH
Eisenwerke Gesellschaf Maximilianshuette mbH
Original Assignee
Eisenwerke Gesellschaf Maximilianshuette mbH
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Priority claimed from DE19691909779 external-priority patent/DE1909779C3/de
Application filed by Eisenwerke Gesellschaf Maximilianshuette mbH filed Critical Eisenwerke Gesellschaf Maximilianshuette mbH
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Publication of US3771998A publication Critical patent/US3771998A/en
Assigned to KLOCKNER CRA TECHNOLOGIE GMBH reassignment KLOCKNER CRA TECHNOLOGIE GMBH ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: EISENWERK GESELLSCHAFT MIXIMILIANSHUTTE MBH
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/30—Regulating or controlling the blowing
    • C21C5/34—Blowing through the bath
    • 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
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/42—Constructional features of converters
    • C21C5/46—Details or accessories
    • C21C5/48—Bottoms or tuyéres of converters

Definitions

  • ABSTRACT The invention relates to a method of refining pig iron, particularly with a high phosphorus component, in a bottom blown converter in which oxygen mixed with powdered lime is blown into the melt through the bottom of the converter.
  • the jets of oxygen mixed with suspended powdered lime blown into the melt through the bottom of the converter are protected by a surrounding sheath of a jacket gas which is preferably inert or slow to react with the melt.
  • High phosphorus pig irons are usually refined by the customary Thomas process, or by the more recently developed LDAC process, the melt being refined under a slag which is high in lime.
  • LDAC process pure oxygen mixed with powdered lime is blown from above onto the surface of the molten mixture through a watercooled lance, the molten mixture consisting of pig iron, scrap and the necessary amount of lime.
  • This process compared to the customary Thomas process, allows the phosphorus removal to proceed early during the refining, that is to say the phosphorus is removed simultaneously with the carbon.
  • a further important disadvantage of the LDAC process is that to bring the phosphorus content down sufficiently it is necessary to use two slags one after the other.
  • the refining has to be interrupted at a carbon content of between 0.7 and 1 percent, and the slag removed.
  • the resulting slag, from this first part of the refining process contains approximately percent iron and 20 percent phosphoric acid, assuming that the phosphorus in the melt is approximately 0.2 percent,
  • the blow is then continued, a quantity of powdered lime being blown in, with the result that a new slag is formed, allowing the phosphorus content to be reduced down to below 0.025 percent.
  • the slag produced during the second blow is left in the converter to act as the first slag for the next charge.
  • the LDAC process is comparatively ineffective in removing phosphorus. This is due to the fact that after the carbon has been removed the melt is agitated only by the jet of oxygen. The movement of metal in the bath is therefore limited almost entirely to a comparatively shallow surface layer. The jet of oxygen produces a hot spot on the surface of the melt, causing a considerable quantity of the iron to go into the slag. This not only results in a poor yield, but also produces large quantities of the undesired brown smoke.
  • the older Thomas process in which air or air mixed with a certain amount of extra oxygen, is blown into the melt through nozzles installed in the converter bottom, possesses certain advantages and certain disadvantages.
  • the advantages of the Thomas process are that the oxygen in the blow oxidises the iron to ferrous oxide near the outlets of the nozzles.
  • the ferrous oxide acts as a carrier for oxygen and efficiently removes impurities from the iron, in the sequence: silicon, manganese, carbon, phosphorus. These reactions take place all through the body of the melt, which is thoroughly agitated by the ballast nitrogen in the blow.
  • the diffusion paths are comparatively short.
  • the nitrogen in the blow which is at least 60 percent of the blown air, unavoidably increases the nitrogen content of the steel, and also causes important heat losses.
  • the amount of scrap which can be added to the charge is therefore comparatively low. It is not feasible to increase the oxygen in the blow to above 40 percent, due to the resulting production of large quantities of brown smoke, and due to very rapid wear of the converter bottom, even if copper blow tubes are used.
  • the Thomas process has a still further disadvantage, in that the oxidation of the phosphorus does not begin until carbon removal is almost complete, that is to say there is a transition point, and phosphorus removal does not begin until this is reached.
  • the object of the present invention is therefore to provide a process for refining pig iron, particularly high phosphorus pig iron, in which pure oxygen loaded with powdered lime is blown into the melt through the converter bottom, the process producing very little brown smoke and the phosphorus removal taking place simultaneously with the remqyal of carbon.
  • a further object is to produce a slag containing a high concentration of soluble phosphoric acid, which is suitable for application as a fertiliser.
  • a method of refining a melt of pig iron in a bottom blow converter comprises blowing at least one jet consisting of a mixture of oxygen with powdered lime suspended in it into the melt through the bottom of the converter the jet being surrounded by a sheath ofjacket gas.
  • the jacket gas is preferably either an inert gas or a gas which is slow to react.
  • the blowing, according to the invention, of a jet containing reagent in suspension, surrounded by a sheath of jacket gas, has the effect of slowing down the violent reaction between the oxygen and the melt, at the same time protecting the nozzles themselves and the converter bottom from slag formation by reaction with the oxygen.
  • the production of brown smoke is at the same time decreased to such a degree that it is no longer necessary to use expensive gas cleaning installations.
  • the metallurgical advantages of the process according to the invention derive from the fact that the ferrous oxide formed by the oxygen at the prevailing high temperatures combines with the powdered lime to form a very reactive slag which rises slowly towards the surface of the melt in the form of a very fine suspension.
  • the advancing of phosphorus removal can be controlled within wide limits by suitably adjusting the grain size of the powdered lime.
  • the grain size of the powdered lime For example using a powdered lime with a maximum grain size of 1 mm, the metallurgical process taking place during the refining is quite similar to what happens in the Thomas process, that is to say very little phosphorus is removed during the removal of the carbon. The phosphorus begins to be separated from the iron only after almost all the carbon has been removed from the melt.
  • a powdered lime which has a maximal grain size of 0.1 mm, it is found that phosphorus is removed even faster than carbon. A melt which contained 0.5 percent of carbon allowed the phosphorus concentration to be brought down to approximately 0.030 percent.
  • the process according to the invention can be used to produce melts which are high in carbon and contain only medium amounts of phosphorus.
  • the high phosphorus slag can be removed and the refining continued using a second slag, to give extremely low phosphorus concentrations.
  • a very fine powdered lime is used, of grain size less than 0.1 mm. It is suprisingly found that not only is the phosphorus removed, but also a large part of the sulphur.
  • the process according to the present invention is not limited to using high phosphorus pig iron as the raw material, although it is in this application that the greatest advantages are obtained.
  • the process can for example be used in the refining of steelmaking pig irons, allowing steels to be obtained which are extremely low in both phosphorus and sulphur. Only quite small quantities of slag are required. Hardly more than half the amount of lime is necessary, compared to the usual process in which the lime is simply added to the melt.
  • jacket gas hydrogen and hydrocarbons have been found to be particularly suitable. These jacket gases have a cooling effect around the nozzle outlets, and effectively protect the nozzles and also the converter bottom from wear.
  • the oxygen conveying the powdered lime in suspension can if desired be blown into the melt at an angle with respect to the surface of the melt, so as to produce a circulation in the melt.
  • the nozzles themselves are inclined at an angle. If this is done then the slag can be blown out of the converter by means of a jet of combustion gas containing now powdered lime.
  • This variant of the process according to the invention produces particularly advantageous results when it is desired to make a steel containing extremely little phosphorus and with the lowest possible loss of iron.
  • the first slag is removed at the end of about of the total blowing time. The blow is completed using increased amounts of powdered lime.
  • the powdered lime can if desired be blown into the converter through all the nozzles.
  • some of the nozzles can be fed with pure oxygen, in which case these pure oxygen jets are also protected with sheaths of jacket gas, to prevent the formation of brown smoke.
  • all that is necessary is to finish the blow using a mixture containing between 10 and 20 percent of pure oxygen and between and 80 percent of nitrogen.
  • suspensions of other solids based for example on iron ore, fluorspar, sodium hydroxide, or bauxite, and if desired these solids can be mixed with powdered lime. In this way the refining process can be influenced in one direction or another.
  • a particularly efficient utilisation of the slag forming substances, mainly the lime, is obtained by blowing them equally distributed through all the nozzles.
  • the refining process may require a change in the quantities used udring the refining. For example it has been found advantageous to increase the addition of lime towards the end of the blow.
  • the process according to the invention is preferably conducted in a bottom blow converter, which, in accordance with another feature of the invention comprises a steel jacket with a refractory lining and an inserted refractory floor containing nozzles, at least one nozzle consisting of a feed pipe for the oxygen-lime mixture surrounded by a concentric feed pipe for the jacket gas.
  • Oxygen pressure is between 6 and 10 atmospheres gauge.
  • the oxygen contains between 1 and 2 lrg/Nrn of powdered lime.
  • the pipe conveying the reagents has an internal diameter not more than 1/35 of the depth of the melt.
  • the velocity of flow of the oxygen containing the powdered lime is about 30 percent less than that of the oxygen containing no lime.
  • the pure oxygen flows at 200 Nm /h per cm of nozzle cross section, whereas the oxygen loaded with powdered lime flows at the rate of approximately Nm lh cm of nozzle cross section.
  • the suspension of reagent is conveyed into the converter for example through a conical pot mounted under the converter floor, the mixture reaching the pot through a tangential supply pipe and leaving the pot through at least one distributor feed pipe leading away radially away from the pot and situated at a distance from the supply pipe.
  • a very even distribution of the powdered lime is obtained by connecting the supply pipe to the distributor pot near the top, and connecting several equally spaced distributor feed pipes to the lower part of the pot.
  • the converter may have a cylindrical distributor pot mounted underneath the converter floor, the cylindrical distributor pot being sub-divided into two compartments by a horizontal intermediate partition wall which is permeable to gas.
  • the suspension is fed into the upper part of the pot through a reagent supply pipe. Pure oxygen is fed to the lower part of the distributor pot through an oxygen supply pipe.
  • At least one distributor feed pipe is connected radially to the upper part of the pot.
  • the suspension of reagents is distributed to the converter nozzles through several reagent distributor pipes spaced at equal distances apart and connected radially to the upper part of the distributor pot.
  • the suspension of reagents can if desired be conveyed into the converter through a distributor duct of shallow rectangular cross section mounted underneath the converter floor.
  • the distributor is sub-divided near its outlet end into several individual reagent ducts.
  • the distributor duct is curved in a plane extending at right angles to its wider surfaces.
  • the distributor is branched into separate channels preferably by means of divergent separating walls, so as to form equally spaced individual channels.
  • the converter is preferably a'body of rotation symmetrical about its longitudinal axis, to allow slag to be poured off to one side, and molten metal to the other side, with the converter in its reclining position.
  • FIG. 1 is a longitudinal axial section through one converter
  • FIG. 2 is a plan view of the bottom of the converter of FIG. 1;
  • FIG. 3 is a view similar to FIG. 1 but through a modified converter
  • FIG. 4 is a plan view of the bottom of the converter of FIG. 3;
  • FIG. 5 represents diagrammatically another form of distributor for a converter.
  • the converter illustrated in FIGS. 1 and 2 consist in the usual way of a steel jacket 8 with a refractory lining 9 and an insert bottom 12 which rests on a bottom plate 11, to which is attached a conical distributor pot 13.
  • a feed pipe 14 for oxygen and powdered lime is joined tangentially to the upper, wider part of the conical distributor pot 13.
  • Radial distributor pipes 15, equally spaced apart, are connected to the lower part of the pot 13.
  • Each distributor pipe 13 curved upwards and penetrates through the bottom 12 of the converter, each distributor pipe 15 being surrounded by a jacket pipe 16 for conveying jacket gas, the two pipes 15 and 16 together forming an injection nozzle for injecting reactive substances into the converter.
  • the oxygen-lime mixture is fed at high velocity through the feed pipe 14 into the conical distributor pot 13, producing a vortex in the pot so that the powdered lime is thrown outwards against the wall of the pot.
  • the finely powdered lime circulates several times around the wall of the pot before it finally escapes through one of the radial distributor pipes 15, along which it is conveyed by the current of oxygen before being injected into the melt.
  • a large number of test melts have been made using this system of injection, and they have shown that the powdered lime distributes itselfevenly among the injection nozzles, even if the feed of powdered lime fluctuates.
  • a cylindrical distributor pot 17 instead of the conical distributor pot 13, there can, as shown in FIGS. 3 and 4, be attached to the base plate 11 a cylindrical distributor pot 17, the interior of which is sub-divided into two compartments by an intermediate partition wall 18 made of a porous material through which gas can pass, that is to say a material permeable to gas.
  • Oxygen is fed in through a feed pipe 19 into the lower part of the cylindrical distributor pot 17.
  • Oxygen-lime mixture is fed into the upper part of the pot through a feed pipe 21.
  • Distributor pipes 22 for the reagents are connected radially and evenly spaced to the upper part of the cylindrical distributor pot 17.
  • FIG. 5 shows a distributor 23 which is a duct of rectangular cross section split at outlet end into several individual ducts 24 each connected to its own distributor pipe (not shown), for feeding the reagents to the melt.
  • the rectangular distributor 23 has a curvature, that is to say its wide sides 26 curve around, to the effect that the powdered lime particles entering at 25 are subjected to a centrifugal force, which is several times normal gravity due to the high velocity of flow.
  • the powdered lime particles therefore distribute themselves as an even layer over the inner surface of the outer wall 26 of the distributor 23.
  • the side walls 27 of the individual channels 24 sub-divide the stream of powdered lime into evenly distributed individual streams, so that here again there is obtained an even distribution of the powdered lime to the several individual nozzles conveying the reagents into the converter.
  • the process according to the invention has a number of metallurgical advantages and eliminates the two main disadvantages of the customary Thomas process, that is to say the great production of brown smoke and the introduction into the converter of large quantities of nitrogen, which not only increase the nitrogen content of the steel but also involve a considerable loss of heat.
  • the new process gives a quiet refining process and the yield is high, partly because very little iron is lost to the slag and partly due to the absence of brown smoke production.
  • a further advantage is that no bal last nitrogen is necessary and consequently very little lime is lost in the effluent gases. The heat losses are also very low. Due to the highly efficient utilisation of the lime, and the resulting high degree of phosphorous re moval, a particularly high fraction of scrap can be added to the charge.
  • a method of refining a melt of pig iron in a bottom blow converter having a plurality of nozzles in the bottom thereof, each nozzle being formed of a pair of coaxial ducts said method comprising blowing into said melt from the bottom toward the top thereof, through a plurality of said nozles, jets consisting of a mixture of oxygen with powdered lime suspended therein from the inner ducts, respectively, of said pair of coaxial ducts at the bottom of said converter, and simultaneously blowing, into said melt hydrocarbon in the form of sheaths respectively surrounding said jets from the outer ducts, respectively, of said pairs of coaxial ducts, forming a suspension of lime in said oxygen and then conveying said lime-oxygen suspension to said inner ducts by means whereby said lime is provided to said nozzles in substantially equal amounts.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (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)
US00821802A 1969-02-27 1969-05-05 Method and converter for refining pig iron Expired - Lifetime US3771998A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19691909779 DE1909779C3 (de) 1969-02-27 Vorrichtung zum Einleiten von im Sauerstoffstrom suspendierten Feststoffteilchen für einen nach dem Mantelgasverfahren betriebenen Konverter

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US3771998A true US3771998A (en) 1973-11-13

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US00821802A Expired - Lifetime US3771998A (en) 1969-02-27 1969-05-05 Method and converter for refining pig iron
US00119258A Expired - Lifetime US3774894A (en) 1969-02-27 1971-01-18 Method and converter for refining pig iron

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US (2) US3771998A (fr)
JP (2) JPS4911970B1 (fr)
AT (1) AT324377B (fr)
BE (1) BE730545A (fr)
CA (1) CA932538A (fr)
ES (1) ES376557A1 (fr)
FR (1) FR2032433B1 (fr)
GB (1) GB1264539A (fr)
LU (1) LU58309A1 (fr)
SE (1) SE407077B (fr)
SU (1) SU727153A3 (fr)

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3907549A (en) * 1972-08-29 1975-09-23 United States Steel Corp Method of refining in improved Q-BOP vessel
US3909245A (en) * 1973-03-30 1975-09-30 Maximilianshuette Eisenwerk Process for lowering the iron content in nickel melts
US3945820A (en) * 1973-03-03 1976-03-23 Eisenwerk-Gesellschaft Maximilianshutte Mbh Process and immersion lances for introducing oxygen into a metal melt
US3950161A (en) * 1973-08-16 1976-04-13 Eisenwerk-Gesellschaft Maximilianshutte Mbh Process for increasing the life of basic refractory linings in hearth-type furnaces
US3954445A (en) * 1974-08-30 1976-05-04 United States Steel Corporation Method of controlling temperature in Q-BOP
US3955965A (en) * 1973-04-04 1976-05-11 Fried. Krupp Gesellschaft Mit Beschrankter Haftung Refining metals
US3967955A (en) * 1974-04-16 1976-07-06 Uddeholms Aktiebolag Method for treating a metal melt
US3970446A (en) * 1972-11-24 1976-07-20 United States Steel Corporation Method of refining an iron base melt
US3985550A (en) * 1975-01-23 1976-10-12 United States Steel Corporation Method of producing low sulfur steel
US3999977A (en) * 1973-04-25 1976-12-28 United States Steel Corporation Method for controlling the injection of flux into a steelmaking vessel as a function of pressure differential
US3999978A (en) * 1975-09-29 1976-12-28 Nippon Steel Corporation Method for making steel by the use of a flux treated by carbon dioxide
US4065297A (en) * 1976-09-28 1977-12-27 Sumitomo Metal Industries Limited Process for dephosphorizing molten pig iron
US4093452A (en) * 1975-07-23 1978-06-06 British Steel Corporation Refining liquid metal
US4165980A (en) * 1972-01-13 1979-08-28 Gfe Gesellschaft Fur Elektrometallurgie Mit Beschrankter Haftung Method of rapidly decarburizing ferro- alloys with oxygen
US4200453A (en) * 1977-10-29 1980-04-29 Larco, Societe Miniere Et Metallurgique De Larymna S.A. Process for the production of nickel alloys
US4242126A (en) * 1979-07-11 1980-12-30 Skw Trostberg Aktiengesellschaft Process for the treatment of iron melts and for increasing the scrap portion in the converter
US4261551A (en) * 1978-06-13 1981-04-14 Eisenwerk-Gesellschaft Maximilianshutte Mbh. Method and means for supplying nozzles with gaseous and/or liquid hydrocarbons
US4272286A (en) * 1978-07-17 1981-06-09 Pennsylvania Engineering Corporation Metallurgical vessel
US4334921A (en) * 1979-04-16 1982-06-15 Nippon Steel Corporation Converter steelmaking process
US4356032A (en) * 1980-06-28 1982-10-26 Kawasaki Steel Corporation Method of dephosphorizing molten pig iron
US4385753A (en) * 1980-03-05 1983-05-31 Creusot-Loire Tuyere for the simultaneous and separate introduction of at least one gas and one powder material
US4388113A (en) * 1980-09-26 1983-06-14 Nippon Steel Corporation Method of preventing damage of an immersed tuyere of a decarburization furnace in steel making
US4392886A (en) * 1980-02-29 1983-07-12 Kawasaki Steel Corporation Method of recovering CO-rich exhaust gas in refining of metal
US4411696A (en) * 1980-03-21 1983-10-25 Nippon Steel Corporation Steelmaking process with separate refining steps
US4422873A (en) * 1980-08-30 1983-12-27 Kawasaki Steel Corporation Blowing method in a top and bottom blowing converter
US4511396A (en) * 1982-09-01 1985-04-16 Nixon Ivor G Refining of metals
US4541617A (en) * 1982-04-23 1985-09-17 Sumitomo Metal Industries Lance structure for oxygen-blowing process in top-blown converters
US4808220A (en) * 1987-03-11 1989-02-28 Thyssen Stahl Ag Process for the preparation of refined ferromanganese

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1592786A (en) * 1976-10-19 1981-07-08 Usinor Bottom blown metallurgical converter
GB8609063D0 (en) * 1986-04-14 1986-05-21 British Steel Corp Injection elements for melt containing vessels
GB9307606D0 (en) * 1993-04-13 1993-06-02 Sanderson Kayser Limited Improvements relating to reaction chambers

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Publication number Priority date Publication date Assignee Title
BE632141A (fr) *
DE494011C (de) * 1928-02-19 1930-03-17 Eisen Und Stahlwerk Hoesch A G Windfrischverfahren und Vorrichtung, bei welchem durch den Konverterboden Brennstoffe, Erze, Kalkstein oder andere Zuschlaege in Pulverform, und zwar jede fuer sich, getrennt in der Windleitung von unten eingefuehrt werden
US2977108A (en) * 1958-04-10 1961-03-28 United States Steel Corp Tuyere assembly for a bessemer converter
US3079249A (en) * 1959-02-27 1963-02-26 Air Liquide Method for refining iron using technically pure oygen
NL296346A (fr) * 1962-08-07
FR90233E (fr) * 1966-06-27 1967-11-03 Air Liquide Perfectionnement aux injecteurs, tuyères et brûleurs pour fours métallurgiques
FR1362355A (fr) * 1963-07-09 1964-05-29 Siderurgie Fse Inst Rech Boîte à vent pour insuffler dans un convertisseur un vent chargé de matières pulvérulentes
FR1450718A (fr) * 1965-07-12 1966-06-24 Air Liquide Perfectionnements à des procédés métallurgiques

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4165980A (en) * 1972-01-13 1979-08-28 Gfe Gesellschaft Fur Elektrometallurgie Mit Beschrankter Haftung Method of rapidly decarburizing ferro- alloys with oxygen
US3907549A (en) * 1972-08-29 1975-09-23 United States Steel Corp Method of refining in improved Q-BOP vessel
US3970446A (en) * 1972-11-24 1976-07-20 United States Steel Corporation Method of refining an iron base melt
US3945820A (en) * 1973-03-03 1976-03-23 Eisenwerk-Gesellschaft Maximilianshutte Mbh Process and immersion lances for introducing oxygen into a metal melt
US3909245A (en) * 1973-03-30 1975-09-30 Maximilianshuette Eisenwerk Process for lowering the iron content in nickel melts
US3955965A (en) * 1973-04-04 1976-05-11 Fried. Krupp Gesellschaft Mit Beschrankter Haftung Refining metals
US3999977A (en) * 1973-04-25 1976-12-28 United States Steel Corporation Method for controlling the injection of flux into a steelmaking vessel as a function of pressure differential
US3950161A (en) * 1973-08-16 1976-04-13 Eisenwerk-Gesellschaft Maximilianshutte Mbh Process for increasing the life of basic refractory linings in hearth-type furnaces
US3967955A (en) * 1974-04-16 1976-07-06 Uddeholms Aktiebolag Method for treating a metal melt
US3954445A (en) * 1974-08-30 1976-05-04 United States Steel Corporation Method of controlling temperature in Q-BOP
US3985550A (en) * 1975-01-23 1976-10-12 United States Steel Corporation Method of producing low sulfur steel
US4093452A (en) * 1975-07-23 1978-06-06 British Steel Corporation Refining liquid metal
US3999978A (en) * 1975-09-29 1976-12-28 Nippon Steel Corporation Method for making steel by the use of a flux treated by carbon dioxide
US4065297A (en) * 1976-09-28 1977-12-27 Sumitomo Metal Industries Limited Process for dephosphorizing molten pig iron
US4200453A (en) * 1977-10-29 1980-04-29 Larco, Societe Miniere Et Metallurgique De Larymna S.A. Process for the production of nickel alloys
US4261551A (en) * 1978-06-13 1981-04-14 Eisenwerk-Gesellschaft Maximilianshutte Mbh. Method and means for supplying nozzles with gaseous and/or liquid hydrocarbons
US4272286A (en) * 1978-07-17 1981-06-09 Pennsylvania Engineering Corporation Metallurgical vessel
US4334921A (en) * 1979-04-16 1982-06-15 Nippon Steel Corporation Converter steelmaking process
US4242126A (en) * 1979-07-11 1980-12-30 Skw Trostberg Aktiengesellschaft Process for the treatment of iron melts and for increasing the scrap portion in the converter
US4392886A (en) * 1980-02-29 1983-07-12 Kawasaki Steel Corporation Method of recovering CO-rich exhaust gas in refining of metal
US4385753A (en) * 1980-03-05 1983-05-31 Creusot-Loire Tuyere for the simultaneous and separate introduction of at least one gas and one powder material
US4411696A (en) * 1980-03-21 1983-10-25 Nippon Steel Corporation Steelmaking process with separate refining steps
US4356032A (en) * 1980-06-28 1982-10-26 Kawasaki Steel Corporation Method of dephosphorizing molten pig iron
US4422873A (en) * 1980-08-30 1983-12-27 Kawasaki Steel Corporation Blowing method in a top and bottom blowing converter
US4388113A (en) * 1980-09-26 1983-06-14 Nippon Steel Corporation Method of preventing damage of an immersed tuyere of a decarburization furnace in steel making
US4541617A (en) * 1982-04-23 1985-09-17 Sumitomo Metal Industries Lance structure for oxygen-blowing process in top-blown converters
US4511396A (en) * 1982-09-01 1985-04-16 Nixon Ivor G Refining of metals
US4808220A (en) * 1987-03-11 1989-02-28 Thyssen Stahl Ag Process for the preparation of refined ferromanganese

Also Published As

Publication number Publication date
AT324377B (de) 1975-08-25
DE1909779B2 (de) 1977-03-31
CA932538A (en) 1973-08-28
SU727153A3 (ru) 1980-04-05
DE1909779A1 (de) 1971-02-04
FR2032433B1 (fr) 1974-06-14
JPS5124447B1 (fr) 1976-07-24
JPS4911970B1 (fr) 1974-03-20
FR2032433A1 (fr) 1970-11-27
LU58309A1 (fr) 1969-07-15
ES376557A1 (es) 1972-04-16
US3774894A (en) 1973-11-27
SE407077B (sv) 1979-03-12
BE730545A (fr) 1969-09-01
GB1264539A (fr) 1972-02-23

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