Abstract: A slag discharge door apparatus for an electric furnace is disclosed. The apparatus includes a door which is operated by a door operator to open or close a slag discharge outlet of the electric furnace, and a door support which supports the door in such a way that a portion of a lower end of the door overlaps with the door support, so that slag is inhibited from leaking out of the electric furnace through the slag discharge outlet.

Abstract: The present invention relates to a system fixing carbon dioxide. The system comprises a first reactor for extracting alkali metal components from a slag and a second reactor for carbonating the extracted alkali metal component with carbon dioxide. With this system, carbon dioxide can be fixed in a simpler and cost-effective manner.

Abstract: The present invention provides a method for carbon dioxide fixation, which comprises extracting an alkali metal component from a raw slag in a first reactor by using an ammonium salt solvent to produce a solution containing the extracted alkali metal component and then reacting the solution with carbon dioxide in a second reactor to produce a carbonate precipitate. With this method, an alkali metal component can be extracted and a carbonate precipitate can be obtained in a simpler and cost-effective manner, among others.

Abstract: The present invention provides an apparatus for solidifying and converting carbon dioxide into carbonate, comprising: an alkali component extraction reactor for extracting an alkali metal component from a raw slag; a carbonation reactor for injecting carbon dioxide into an alkali metal component solution containing the extracted alkali metal component to produce a carbonate precipitate from the alkali metal component solution; a first filtration device connected between the alkali component extraction reactor and the carbonation reactor to separate a post-treatment slag, from which the alkali component is extracted, from the alkali metal component solution; and a second filtration device connected between an inlet of the alkali component extraction reactor and an outlet of the carbonation reactor to separate the carbonate from the alkali metal component solution after the carbonation reaction.

Abstract: The quenchable steel sheet has an alloy composition including carbon (C) in an amount of 0.15 to 0.30 wt %, silicon (Si) in an amount of 0.05 to 0.5 wt %, manganese (Mn) in an amount of 1.0 to 2.0 wt %, boron (B) in an amount of 0.0005 to 0.0040 wt %, sulfur (S) in an amount of 0.003 wt % or less, phosphorus (P) in an amount of 0.012 wt % or less, one or more selected from among calcium (Ca) in an amount of 0.0010 to 0.0040 wt % and copper (Cu) in an amount of 0.05 to 1.0 wt %, two or more selected from among cobalt (Co), zirconium (Zr) and antimony (Sb), and iron (Fe). Alloy elements are controlled to increasing hot ductility and enabling pressing at 600 to 900° C. so that a tensile strength of 1400 MPa or more and an elongation of 8% or more are obtained after pressing.

Abstract: The present invention relates to a mold powder supply apparatus using the waste heat of a tundish, which can collect waste heat from molten steel in the tundish, and preheat and dry mold powder. The mold powder supply apparatus using the waste heat of a tundish according to an embodiment of the present invention includes: a powder hopper that is mounted to a frame close to a tundish to absorb heat radiated from the top of the tundish, through one side; an agitator that agitates mold powder filled in the powder hopper; and a supply pipe that is connected to the bottom of the powder hopper to supply the powder hopper into a mold.

Abstract: A method of continuous casting a beam blank adapted for impact absorption is disclosed. The method includes: introducing molten steel into a continuous casting mold from a tundish through an immersion nozzle to perform non-oxidation casting, wherein the immersion nozzle is disposed at one side of the continuous casting mold forming both side flanges of a beam blank, and the molten steel is introduced into the continuous casting mold through the immersion nozzle. The method is advantageous in that it is possible to produce steel adapted for low-temperature impact absorption, and productivity is improved due to the increase of the number of consecutive heats of continuous casting.

Abstract: The quenchable steel sheet has an alloy composition including carbon (C) in an amount of 0.15˜0.30 wt %, silicon (Si) in an amount of 0.05˜0.5 wt %, manganese (Mn) in an amount of 1.0˜2.0 wt %, boron (B) in an amount of 0.0005˜0.0040 wt %, sulfur (S) in an amount of 0.003 wt % or less, phosphorus (P) in an amount of 0.012 wt % or less, one or more selected from among calcium (Ca) in an amount of 0.0010˜0.0040 wt % and copper (Cu) in an amount of 0.05˜1.0 wt %, two or more selected from among cobalt (Co), zirconium (Zr) and antimony (Sb), and iron (Fe). Alloy elements are controlled to increasing hot ductility and enabling pressing at 600˜900° C. so that a tensile strength of 1400 MPa or more and an elongation of 8% or more are obtained after pressing.

Abstract: Disclosed is a method of predicting surface quality of a thin slab hot rolled coil. The method includes calculating the Cu equivalent (Cu eq.) of molten steel, applying the calculated Cu equivalent of the molten steel into an equation: 120×(Cu equivalent)2?6×(Cu equivalent) to calculate a surface crack index, and predicting the generation of surface defect of the thin slab hot rolled coil by the surface crack index. A method of producing the thin slab hot rolled coil using the same is also provided. The surface crack defect of the thin slab hot rolled coil can be predicted by calculating the Cu equivalent of the molten steel, and thus a thin slab which meets the quality standard demanded by a consumer can be provided, and this results in increased productivity and product reliability.

Abstract: A slag discharge door apparatus for an electric furnace is disclosed. The apparatus includes a door which is operated by a door operator to open or close a slag discharge outlet of the electric furnace, and a door support which supports the door in such a way that a portion of a lower end of the door overlaps with the door support, so that slag is inhibited from leaking out of the electric furnace through the slag discharge outlet.

Abstract: A method and system of fixing carbon dioxide is provided. After metal ion components are extracted from, e.g., natural mineral or steel slag through acid treatment, carbon dioxide is injected to fix carbon dioxide by carbonating the same. Since the procedure of pH adjustment is unnecessary, the reaction is carried out effectively and a continuous process is enabled. Accordingly, the disclosed method of fixing carbon dioxide enables effective removal of carbon dioxide produced from the steelmaking industry, thereby significantly reducing greenhouse gas emission and allowing recycling of the discarded steel slag.

Abstract: An apparatus for measuring a temperature of a material includes a body unit disposed on an exit side of a heating furnace; a temperature measuring unit installed on the body unit and constructed to measure a temperature of a material which is extracted from the heating furnace; a foreign substance removing unit installed on the body unit and constructed to inject a fluid toward the material so as to remove foreign substances adhered to the material; and a moving unit installed on the body unit and constructed to move the temperature measuring unit.

Abstract: A device for measuring a speed of a material includes a body unit disposed at an exit side of a rolling stand and placed below a material which is transferred from the rolling stand; and a speed measuring unit installed on the body unit and constructed to measure a speed of the material transferred from the rolling stand.

Abstract: Disclosed is a method and apparatus for recovering valuable metals from slag and manufacturing multifunctional aggregate, wherein a reducing agent is fed into molten slag discharged into a slag pot or a slag reforming pot from a converter or an electric arc furnace thus recovering valuable metals from the molten slag, and then the molten slag is formed into a lightweight porous structure. Accordingly, the valuable metals (Fe, Mn) are recovered from the slag discharged from the converter or electric arc furnace, and slag having low specific gravity is ensured using foaming and controlled cooling and then formed into multifunctional aggregate.

Abstract: The present invention relates to a die apparatus which cools metals after hot pressing. More specifically, the present invention relates to an immersion cooling type die apparatus, in which dies are immersed in a coolant to enhance a cooling rate of the dies while guaranteeing uniform quality. The die apparatus includes an upper die having a pressing surface formed on a lower surface thereof, a lower die having a pressing surface formed on an upper surface thereof, a coolant bath storing a predetermined level of coolant, and a pressing unit driven to lower and compress the upper die onto the lower die, to lower both the upper and lower dies in a compressed state, and to lift the upper and lower dies in a reverse sequence.

Abstract: Disclosed is a method of predicting surface quality of a thin slab hot rolled coil. The method includes calculating the Cu equivalent (Cu eq.) of molten steel, applying the calculated Cu equivalent of the molten steel into an equation: 120×(Cu equivalent)2?6×(Cu equivalent) to calculate a surface crack index, and predicting the generation of surface defect of the thin slab hot rolled coil by the surface crack index. A method of producing the thin slab hot rolled coil using the same is also provided. The surface crack defect of the thin slab hot rolled coil can be predicted by calculating the Cu equivalent of the molten steel, and thus a thin slab which meets the quality standard demanded by a consumer can be provided, and this results in increased productivity and product reliability.

Abstract: A method for evaluating center segregation of a continuous cast slab is provided. The method of the present invention includes (A) creating a center segregation image of a slab using an etching solution comprising a picric acid (C6H3N3O7), a cupric chloride (CuCl2), sodium laurylbenzenesulfonate (C18H29SO3Na) and the remainder of distilled water; and (B) evaluating the center segregation of a slab by scanning the image and applying the following Formula. The method creates an image of center segregation even for low-carbon steel having carbon (C) in an amount of 0.04 wt % or less as well as ultra low-sulfur steel having sulfur (S) in an amount of 50 ppm or less.

Abstract: A method of continuous casting a beam blank adapted for impact absorption is disclosed. The method includes: introducing molten steel into a continuous casting mold from a tundish through an immersion nozzle to perform non-oxidation casting, wherein the immersion nozzle is disposed at one side of the continuous casting mold forming both side flanges of a beam blank, and the molten steel is introduced into the continuous casting mold through the immersion nozzle. The method is advantageous in that it is possible to produce steel adapted for low-temperature impact absorption, and productivity is improved due to the increase of the number of consecutive heats of continuous casting.

Abstract: A method of recovering a valuable metal from slag is disclosed. The method includes the steps of: applying a magnetic field whose magnitude is increased in a stepwise fashion to crushed slag to separate a magnetic material from the crushed slag; and introducing a reductant into the separated magnetic material to recover a valuable metal therefrom. The method is advantageous and cost effective because the recovery rate of iron (Fe) from slag exceeds 50% by using a magnetic field, thus reducing the amount of slag to be wasted.

Abstract: An apparatus for measuring the temperature of a rolling material is capable of accurately measuring the temperature of a rolling material by putting a temperature-measuring unit in contact with a surface of the rolling material that is extracted from a heating furnace and conveyed on a roller table to the next process, and moving the temperature-measuring unit contacting the surface of the rolling material together with the rolling material in the conveyed direction thereof.