Classifications

• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
  • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
  • C21C7/0025—Adding carbon material
• • 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
  • C21C7/0037—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 by injecting powdered material
• • 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
  • C21C7/0075—Treating in a ladle furnace, e.g. up-/reheating of molten steel within the ladle
• • 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
  • C21C7/0087—Treatment of slags covering the steel bath, e.g. for separating slag from the molten metal
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
  • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
  • C21C7/04—Removing impurities by adding a treating agent
  • C21C7/06—Deoxidising, e.g. killing
• • 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
  • C21C7/0056—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 using cored wires
  • C21C2007/0062—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 using cored wires with introduction of alloying or treating agents under a compacted form different from a wire, e.g. briquette, pellet

Definitions

• the invention relates to a mixture for introduction into the slag contained in a molten metal in iron and steel metallurgy, to the use of such a mixture, and to a process for conditioning an iron and steel metallurgy on a molten metal in a metallurgical vessel, for example in a converter , in an electric arc furnace or in a pan, located slag.
• the pig iron melt is separated from unwanted components before it is cast.
• oxygen by means of a lance on in a supplied with a basic refractory material converter inflated pig iron melt inflated.
• the process of this inflation of oxygen on the pig iron melt is also referred to as fresh.
• fresh iron companion especially iron companion in the form of carbon, manganese, silicon and phosphorus are oxidized by the injected oxygen and form together with added quicklime on the molten metal floating slag layer.
• the crude steel melt is produced by the melting of scrap, pig iron, molten iron and / or sponge iron and other raw materials.
• the slag must be specifically influenced or conditioned with regard to chemical and physical properties.
• the basicity ie the mass or molar ratio of the basic components to the other components of the slag (which can be calculated, for example, according to the following formula: [xCaO + MgO] / [xSiO 2 + Al 2 O 3 + other components])
• the first acidic or non-basic slag are increased to the corrosive attack of Slag on the basic delivery of the metallurgical vessel in which the molten metal is located, and thereby reduce the wear of the delivery and to increase their service life.
• slag conditioners have a component that increases the basicity of the slag, in particular lime, dolomitic lime or dolomite.
• slag-washing in which the slag is distributed by pivoting the converter on the tapping and Chargierseite.
• slag-splashing is another method of care.
• slag-foaming slag is chemically foamed by adding a carbon carrier.
• the slag foam foamed slag is also known as “foamed slag”.
• the foamed slag has insulating properties, so that the heat losses from the melt can be reduced and energy can be saved. Furthermore, components of the metallurgical vessel in which the molten iron is located can be protected from heat radiation by the foamed slag.
• the object of the invention is to provide a slag conditioner by means of which the basicity and the MgO content of the slag can be increased rapidly in order to prevent the slag from attacking the refractory lining of the metallurgical vessel, in which the slag conditioner Molten metal with the slag on it is able to reduce.
• Another object of the invention is to provide a slag conditioner which has a high reactivity while being easy to handle.
• Another object of the invention is to provide a slag conditioner by which foaming of the slag can be achieved.
• a further object of the invention is to provide a slag conditioner by which an increase in the iron yield of the primary metallurgical process can be achieved.
• the mixture according to the invention or the slag conditioner according to the invention is suitable for introduction into slags on molten metals in any metallurgical vessel, but in particular for slags in converters, electric arc furnaces and ladles.
• the proportion of Rohdolomit in the mixture according to the invention which is according to the invention in the range of 10 to 90% by mass, fulfills the invention in particular two essential tasks.
• the raw dolomite is abruptly heated on contact with the hot slag, whereby a calcination of Rohdolomits is set in motion. This calcining leads to a foaming of the slag, so that upon introduction of the mixture according to the invention into the slag, a foamed slag is formed.
• the calcination of the crude dolomite upon introduction of the mixture into the slag also leads to the mixture, if it is introduced into the slag in the form of pellets, spontaneously decomposing and the mixture thereby forming a large specific surface with a high reactivity.
• MgO and CaO formed from the crude dolomite after its calcination Due to the proportion of MgO and CaO formed from the crude dolomite after its calcination, the basicity of the slag is increased. Furthermore, MgO saturation of the slag can be achieved by the proportion of MgO formed after calcination of the crude dolomite, so that the corrosive attack of the slag on the refractory lining of the metallurgical vessel holding the molten metal is reduced.
• An advantage of the mixture according to the invention is in particular also that this MgO saturation is particularly fast attainable due to the high reactivity of the mixture.
• the mixture according to the invention also comprises one or more further components which comprise MgO and carbon.
• the proportion of carbon of the other components serves to increase the foaming of the slag upon introduction of the mixture into the same.
• the carbon reacts with oxygen in the slag to form carbon oxides, in particular carbon monoxide (CO) and carbon dioxide (CO 2 ).
• CO carbon monoxide
• CO 2 carbon dioxide
• the carbon of the other components of the mixture is oxidized immediately and vigorously with oxygen fractions of the slag, so that it spontaneously foams when the mixture is introduced into the slag.
• the carbon of the mixture can react directly with oxygen of the molten metal and extract oxygen from the molten metal.
• This extracted from the molten metal oxygen must not be removed later in additional steps by deoxidizer, such as aluminum, from the molten metal.
• At least part of the oxygen with which the carbon introduced into the slag from the mixture according to the invention reacts originates from iron oxides in the slag, which are reduced by the carbon to metallic iron. As a result, the yield of recovered iron is increased in the overall process.
• the proportion of MgO of the other components serves, in particular, to be able to set the basicity and the MgO saturation of the slag in a targeted manner as a function of the other components of the mixture.
• the component of the mixture in the form of crude dolomite is crude, ie natural, essentially untreated, in particular uncalcined dolomite.
• crude dolomite is a rock with the main mineral dolomite (CaMg (CO 3 ) 2 or CaCO 3 • MgCO 3 ).
• Dolomite has Rohdolomit regularly to at least 90% by mass, based on the Rohdolomit on.
• natural impurities may be present, for example in the form of Fe 2 O 3 , SiO 2 or Al 2 O 3 .
• a crude dolomite having a proportion of dolomite of at least 90% by mass, based on the crude dolomite, in particular having at least 91, 92, 93, 94, 95 or 96% dolomite.
• Rohdolomit can be present in the mixture according to the invention in a proportion in the range of 10 to 90% by mass, that is, for example, in a proportion of at least 10, 11, 12, 13, 14 or 15% by mass.
• crude dolomite can be present in the mixture according to the invention in a proportion of at most 90, 80, 70, 60, 55, 50, 45, 40, 35, 30 or 25 mass%.
• the at least one other component comprising the mixture besides crude dolomite may be, for example, one or more of magnesite, magnesia, sintered magnesia, fused magnesia, graphite, coke or one or more carbides, for example aluminum carbide.
• one or more of the abovementioned components are present in the mixture according to the invention, which comprise MgO but no carbon (such as magnesite curd, Sintered magnesia or fused magnesia) there is at least one other component comprising carbon (such as at least one of magnesia, graphite, coke or at least one carbide).
• the mixture comprises carbon, but not MgO (such as graphite, coke or at least one carbide), at least one of the aforementioned components comprising MgO (such as magnesite, sintered magnesia or fused magnesia).
• MgO such as graphite, coke or at least one carbide
• MgO such as magnesite, sintered magnesia or fused magnesia
• the further component is in the form of magnesium carbon and optionally at least in the form of another of the aforementioned components.
• the other components are present in the form of magnesium carbon and in the form of magnesite-curd.
• Magnesium oxide is a so-called magnesia product, also known as magnesia or MgO-C, characterized by a magnesia (MgO) granule linked together by a carbon bond.
• MgO magnesia
• magnesium oxide is present in the form of used magnesium carbonate products, ie so-called magnesia carbon outbreaks.
• Such magnesium oxide outbreaks are magnesia petroleum products which have been used in the steel industry, in particular as wear linings of oxygen blowing converters, in electric arc furnaces or in pans. insofar Accordingly, recycled magnesia products may be partly, substantially or exclusively present as magnesium oxide in the mixture according to the invention.
• the invention also relates to the use of recycled magnesia products as raw material for the mixture according to the invention or the use of such recycled magnesia products as a component of a slag conditioner according to the invention.
• the use of magnesium carbon as a carbon carrier in the mixture according to the invention can be particularly advantageous insofar as magnesium oxide, in particular as far as it is present as an outbreak, can approximate the composition of the refractory lining of a metallurgical melting vessel and therefore in the formation of a Foam slag can especially effectively contribute to the care of the delivery by the foamed slag.
• Magnesia chew is magnesite burnt by caustics, sometimes called chewing magnesite or caustic magnesia. Magnesite chew is known to be obtained by caustic burning of magnesite (MgCO 3 ), ie by burning magnesite at low temperatures.
• MgCO 3 magnesite
• An advantage of the use of magnesite cereal in the mixture according to the invention is in particular that it is highly reactive, which is why, when introduced into a slag, it liberates MgO very rapidly and the increase in the basicity of the slag and its MgO saturation can therefore be achieved particularly quickly.
• the mixture according to the invention has particularly advantageous properties, in particular with regard to their reactivity and their action as a foaming agent for the slag, as far as the mixture comprises the further components in the form of magnesia carbon and magnesite-cerium in the following proportions by mass: magnesium oxide: 10 to 50% by mass; Magnesite malt: 10 to 50% by mass. It can be provided according to the invention that only one of the aforementioned components is present in the above-mentioned mass fractions in the mixture.
• magnesium carbon may be present in proportions of at least 10, 15, 20, 25, 30 or 35% by weight in the mixture.
• magnesium oxide may be present in the mixture, for example, in proportions of at most 45 or 40% by mass.
• magnesite malt may be present in proportions of at least 10, 15, 20, 25, 30 or 35% by weight in the mixture. Furthermore, magnesite malt may for example be present in proportions of at most 50 or 45% by weight in the mixture.
• the mixture is present in a relatively small particle size, for example at least 50% by mass, 60% by mass, 70% by mass, 80% by mass, 90% by mass or even 100% by mass in one Grain size less than 5 mm.
• Rohdolomit is present at least 80% by mass, so for example, at least 90% by mass or 100% by mass in a particle size less than 5 mm.
• the other components in particular if they are present in the form of magnesium oxide and magnesite chew, may preferably be present in at least 80% by mass, ie for example at least 90% by mass or 100% by mass in a particle size of less than 1 mm.
• the mixture according to the invention having this very small mean particle size, it is possible to achieve a particularly good and uniform distribution and, in particular, a rapid dissolution of the mixture in the slag.
• the mixture according to the invention In order to be able to achieve good handling of the mixture according to the invention in spite of this small particle size of the mixture, it can be provided to provide the mixture in compacted or pressed form, for example in the form of pellets. In order to provide the mixture in the form of pellets, it can be provided that a mixture according to the invention, which in particular can have the previously described particle size distribution, is pressed into pellets without additions of additives.
• these pellets may have an almond-shaped, rod-shaped or spherical shape, for example with a maximum length of, for example, 50 mm, 40 mm or 30 mm.
• the pellets may also have, for example, a minimum diameter of 5, 10, 15, 20 or 25 mm.
• Pellets of an appropriate size are easy to handle, but at the same time so small that they quickly disintegrate there after entering a slag and the benefits of the invention, small particle size distribution can quickly come to fruition there.
• the spontaneous calcination of the crude dolomite upon introduction of the mixture into the slag causes the pellets to spontaneously disintegrate upon introduction into the slag, promptly disregarding a small grain size or grain size of the mixture having a high surface area and high reactivity to unfold.
• the mixture may have a proportion of magnesium carbonate (MgCO 3 ), for example in the range of 5 to 30% by mass, for example, a proportion of at least 6, 7, 8 or 9% by mass and, for example, in a proportion of at most 25, 20 or 15 mass%.
• the proportion of magnesium carbonate in the mixture can be predominantly or completely present as a constituent of the crude dolomite.
• the proportion of calcium carbonate (CaCO 3 ) in the mixture may, for example, be in the range of 5 to 35% by mass, that is to say for example at least 6, 7, 8, 9, 10% by mass and, for example, also at most 30, 25, 20 or 15 mass%.
• the proportion of calcium carbonate in the mixture may be predominantly or completely present as part of the crude dolomite.
• the proportion of magnesia (MgO) in the mixture may, for example, be in the range from 20 to 60% by mass, for example also at least 25, 30, 35, 40 or 45% by mass and for example also at most 55 or 50% by mass. %.
• the magnesia can be present, for example, in particular in the components magnesia carbon and magnesite chew.
• Carbon may be present in the mixture according to the invention, for example in a proportion in the range of 3 to 15% by mass, ie, for example, in a proportion of at least 4, 5 or 6% by mass and, for example, in a proportion of at most 14, 13, 12 , 11 or 10% by mass. Carbon may be predominantly or completely present in the mixture in the form of magnesium carbon in the mixture.
• Calcium oxide (CaO) which may for example be incorporated into the mixture as a secondary constituent of magnesite chew, can be present in proportions in the range of 0 to 40% by mass in the mixture, for example also in proportions of at least 5, 10 or 15% by weight. % and, for example, also in proportions of at most 35, 30, 25 or 20% by mass.
• the mixture can react very sensitively to other components and substances.
• the mixture according to the invention contains, in addition to components in the form of raw magnesite, magnesium carbon and magnesite chew, fractions of other components in a proportion of less than 10% by mass, ie, for example, in a proportion of less than 9, 8, 7, 6, 5, 4, 3, 2 or 1 mass%.
• the mixture in addition to the aforementioned substances MgCO 3 , CaCO 3 , MgO, C, CaO, SiO 2 , Fe 2 O 3 , Al 2 O 3 , H 2 O, P 2 O 5 , in particular in the aforementioned Mass fractions, other substances only in a proportion of less than 10% by mass, that is, for example, in a proportion of less than 9, 8, 7, 6, 5, 4, 3, 2 or 1% by mass.
• a binder In order to make the mixture according to the invention available in the form of pellets, it can be provided to make the mixture with a binder before it is pressed into pellets.
• a sulphate binder may be provided, for example an Epsom salt solution.
• the concentration of epsom salt in the epsom salt solution may be in the range of 0.1 to 0.3 mass%. It can be provided that the mixture with a proportion of binder in the range of 5 to 15 mass%, based on the mixture without the binder, is made.
• the mixture also comprises one or more temporary binders, for example one or more of the following temporary binders: glucose, starch, one or more silicate binders or one or more phosphatic binders.
• the mixture may, as described herein, so for example, in compacted or compressed form, for example in the form of pellets are provided.
• the mixture can be mixed with one or more of the binders described herein and then pressed into pellets, in particular with the dimensions described herein.
• the provided mixture for example in the form of pellets, is added to the slag and sinks into it so that it can unfold its effect there according to the invention.
• the mixture according to the invention is fundamentally suitable as a slag conditioner for slags on a molten metal in any metallurgical vessel, for example for molten metals in converters, electric arc furnaces or ladles.
• the mixture according to the invention is particularly preferably used as a slag conditioner for slags on molten metals which are located in a metallurgical vessel with a basic feed, ie in particular with a feed based on at least one of the following materials: magnesia, magnesia-carbon, doloma or dolomite. Carbon.
• the invention furthermore relates to the use of a mixture according to the invention described herein for conditioning a slag present in iron and steel metallurgy on a molten metal in a metallurgical vessel.
• the crude dolomite used had a proportion of dolomite of more than 95% by mass, based on the crude dolomite.
• Al 2 O 3 , Fe 2 O 3 and SiO 2 were present as secondary constituents.
• magnesia carbon component was excavated material in the form of recycled magnesia petroleum products.
• this component had a carbon content of 28% by mass, based on the total mass of the components.
• the crude dolomite was present in a particle size of less than 5 mm and the components magnesia carbon and magnesite cereal in a particle size of less than 1 mm.
• the mixture was mixed with 10% binder in the form of Epsom salt based on the mass of the mixture without the binder and pressed into almond-shaped pellets having a thickness of about 15 mm and a length of about 30 mm.
• pellets were then dried at about 300 ° C and, after cooling in this form, made available as a slag conditioner.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Analytical Chemistry (AREA)
• Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
• Carbon Steel Or Casting Steel Manufacturing (AREA)
• Compositions Of Oxide Ceramics (AREA)
• Manufacture And Refinement Of Metals (AREA)

Priority Applications (12)

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• 2014
  • 2014-12-17 HU HUE14198439A patent/HUE034189T2/en unknown
  • 2014-12-17 SI SI201430198A patent/SI3034633T1/sl unknown
  • 2014-12-17 ES ES14198439.3T patent/ES2623457T3/es active Active
  • 2014-12-17 PL PL14198439T patent/PL3034633T3/pl unknown
  • 2014-12-17 EP EP14198439.3A patent/EP3034633B1/de not_active Not-in-force
• 2015
  • 2015-09-21 BR BR112017009332A patent/BR112017009332A2/pt not_active Application Discontinuation
  • 2015-09-21 RU RU2017112347A patent/RU2017112347A/ru not_active Application Discontinuation
  • 2015-09-21 CN CN201580059266.6A patent/CN107148482A/zh active Pending
  • 2015-09-21 WO PCT/EP2015/071607 patent/WO2016096178A1/de active Application Filing
  • 2015-09-21 US US15/529,344 patent/US20170275714A1/en not_active Abandoned
  • 2015-11-03 AR ARP150103544A patent/AR102499A1/es unknown
  • 2015-11-10 TW TW104137004A patent/TW201623189A/zh unknown

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