Patent application number | Description | Published |
20090136887 | ROTARY HEARTH FURNACE - PROBLEM TO BE SOLVED: To provide a rotary hearth furnace which has a simple furnace structure in which the furnace is not damaged even if the furnace is operated for a long term while presenting general equations capable of adequately determining a thermal expansion margin in the rotary hearth furnace. | 05-28-2009 |
20100175510 | PRODUCTION METHOD FOR CARBONACEOUS MATERIAL-CONTAINING METAL OXIDE BRIQUETTES - The present invention is directed to provide a production method for carbonaceous material-containing metal oxide briquettes, capable of ensuring sufficient strength of briquettes while using a metal oxide material containing a large amount of fine particles, such as steel mill dust. This method comprises a mixing step of mixing a metal oxide material A containing a large amount of fine particles with a carbonaceous material B in a mixer | 07-15-2010 |
20100180723 | METHOD FOR MANUFACTURING MOLTEN IRON - A method for manufacturing molten iron includes a step of charging a carbonaceous material, a flux, and solid reduced iron obtained by thermally reducing carbon composite iron oxide agglomerates into an arc melting furnace and melting the solid reduced iron using arc heating in the melting furnace while an inert gas is blown into a molten iron layer contained in the melting furnace from a bottom blowing tuyere disposed on a bottom of the melting furnace to stir the molten iron layer, wherein the carbonaceous material is charged so that a carbonaceous material suspending slag layer in which the carbonaceous material is suspended is formed in an upper portion of a slag layer formed on the molten iron layer by slag produced when the solid reduced iron is melted into the molten iron and so that a carbonaceous material coating layer composed of only the carbonaceous material is further formed on the carbonaceous material suspending slag layer, and the molten iron and the slag stored in the melting furnace are tapped from a tap hole formed in a lower portion of a furnace wall of the melting furnace. | 07-22-2010 |
20100186644 | EXHAUST GAS PROCESSING SYSTEM AND METHOD FOR ROTARY HEARTH TYPE REDUCING FURNACE - Provided are an exhaust gas processing system and method capable of effectively utilizing the sensible heat of an exhaust gas for preheating air for burner combustion in a rotary hearth type reducing furnace while preventing troubles caused by adhesion of dust such as blockage in an exhaust gas processing facility for a rotary hearth type reducing furnace and corrosive deterioration in the facility without increasing the facility costs excessively. The system comprises a radiant heat exchanger | 07-29-2010 |
20100192726 | METHOD FOR REDUCTION TREATMENT OF ELECTRIC FURNACE DUST - It is an object of the present invention to provide a method of compacting a powdery mixture of electric furnace dust and a carbonaceous material into a briquette and subjecting the briquette to a thermal reduction treatment in a rotary hearth furnace, the method being capable of ensuring a strength of the briquette resistant to a handling in a course after the compacting through until it is set in the rotary hearth furnace, and reducing energy necessary for drying of the briquette while preventing bursting thereof in the rotary hearth furnace. The method comprises the steps of: adding a carbonaceous material B and a binder C, and optionally water, to electric furnace dust A generated in a steelmaking electric furnace | 08-05-2010 |
20100229685 | PROCESS FOR PRODUCING MOLTEN IRON - A process for producing molten iron is a process in which while an inert gas is blown into a molten iron layer in an iron bath type melting furnace through bottom-blown tuyeres provided in a hearth bottom thereof to stir the molten iron layer, a carbon material, an additive flux, and solid reduced iron obtained by heating reduction of carbon composite iron oxide briquettes are charged into the above melting furnace, and top blowing of an oxygen-containing gas is performed through a top-blown lance provided for the melting furnace, so that the solid reduced iron is melted by combustion heat obtained by combusting the carbon material and/or carbon in molten iron to form molten iron. In addition, in this process for producing molten iron, the carbon material is charged so as to form a carbon material suspension slag layer in which the carbon material is suspended at an upper layer portion of a slag layer which is formed of slag generated when the solid reduced iron on the molten iron layer is melted into molten iron and further so as to form a carbon material covering layer made of only the carbon material on the carbon material suspension slag layer, and the molten iron and the slag accumulated in the melting furnace are discharged through a taphole provided at a lower portion of a furnace side of the melting furnace. | 09-16-2010 |
20110011209 | METHOD FOR PRODUCING MOLTEN IRON - A method for producing molten iron by melting an iron source material using an iron bath-type melting furnace comprising a top-blowing lance at an upper part of the furnace, a bottom-blowing tuyere in the bottom of the furnace and a tap hole at a lower part on the side of the furnace, the method comprising: a melting process of charging the iron source material, a carbonaceous material and a flux into the furnace and top-blowing an oxygen-containing gas through the top-blowing lance while blowing an inert gas through the bottom-blowing tuyere into melt present in the furnace to stir the melt to thereby melt the iron source material and generate the molten iron and slag using combustion heat of combusting carbon in the carbonaceous material and/or in the molten iron, wherein the melting process has at least one tapping process of discharging the molten iron and the slag through the tap hole while holding a position of the furnace in generating the molten iron, and the tapping process continues or interrupts generation of the molten iron and continues top-blowing of the oxygen-containing gas to thereby keep a temperature of the molten iron in the furnace at or above a pre-set lowest temperature of the molten iron. | 01-20-2011 |
20110156326 | IRON BATH-TYPE MELTING FURNACE - Disclosed is an iron bath-type melting furnace characterized by comprising a furnace body and a plurality of tap holes provided at different positions of the furnace body in the direction of the height thereof so as to extend through the furnace body, and in that an iron source as a raw material together with a carbon material and a slag-making material is charged into the furnace and further an oxygen-containing gas is injected into the furnace to melt the iron source as the raw material by combustion heat generated by combustion of the carbon material and/or carbon contained in the molten iron and to produce molten iron and molten slag are produced, and the plurality of the tap holes is used while switching from the uppermost tap hole toward downward tap holes to tap the iron slag being conducted, whereby molten iron is produced by intermittently taking out the molten iron and the molten slag to the outside of the furnace while maintaining the furnace body erect. | 06-30-2011 |