Abstract: A method of starting a molten-bath based melting process includes commencing supplying cold oxygen-containing gas and cold carbonaceous material into a main chamber of a smelting vessel within at most 3 hours after completing a hot metal charge into the vessel and igniting the carbonaceous material and heating the main chamber and molten metal in the main chamber.

Abstract: A controlled combustion synthesis apparatus comprises an ignition system, a pressure sensor for detecting internal pressure, a nitrogen supply, a gas pressure control valve for feeding nitrogen and exhausting reaction gas, means for detecting the internal temperature of the reaction container, a water cooled jacket, and a cooling plate. A temperature control system controls the temperature of the reaction container by controlling the flow of cooling water supplied to the jacket and the cooling plate in response to the detected temperature. By combustion synthesizing, while controlling the internal pressure and temperature, the apparatus can synthesize a silicon alloy including 30-70 wt. % silicon, 10-45 wt. % nitrogen, 1-40 wt. % aluminum, and 1-40 wt % oxygen.

Abstract: A direct smelting process for producing molten metal from a metalliferous feed material in a direct smelting vessel is disclosed. The process includes using a stream of off-gas from the vessel as a fuel gas in (i) stoves for generating a hot blast of air or oxygen-enriched air for the process and (ii) a waste heat recovery apparatus for generating steam for the process. The process also includes controlling pressure in the vessel by controlling pressure in the off-gas stream while the process is producing molten metal.

Abstract: A transfer pipe of dried concentrate for transferring dried concentrate, having a double pipe structure, comprising an inner pipe 2 through which the dried concentrate is transferred by compressed air, an outer pipe 3 arranged around the outer periphery of the inner pipe 2, and a joint flange 5 forming an annular space 4 sealed between the inner pipe 2 and the outer pipe 3, arranged at both ends of the inner pipe 2 and the outer pipe 3, and integrally fixing the inner pipe 2 and the outer pipe 3; wherein the inner pipe 2 is positioned inside the outer pipe 3 and is formed of a metal pipe 2a forming the annular space 4, a ceramic sleeve 2c forming an innermost layer of the metal pipe, and a filler 2b for fixing the ceramic sleeve 2c provided between the metal pipe 2a and the ceramic sleeve 2c.

Abstract: It has been reported in the literature that raceway measurement made during the decreasing gas velocity is relevant to operating blast furnaces. However, no raceway correlation is available either for decreasing or increasing gas velocity which is developed based on a systematic study and none of the available correlation take care of frictional properties of the material. Therefore, a systematic experimental study has been carried out on raceway hysteresis. Based on experimental data and using dimensional analysis, two raceway correlations, one each for increasing and decreasing gas velocity, have been developed. Also, in the present study the effect of stresses has been considered along with pressure and bed weight terms mathematically. These three forces are expressed in mathematical form and solved analytically for one-dimensional case, using a force balance approach. Based on the force balance approach a general equation has been obtained to predict the size of the cavity in each case, i.e.

Abstract: The present invention: solves the problems of hitherto disclosed technologies, such as insufficient suppression of the oxidation loss of [Cr] and the excessive erosion of refractories, in the decarburization-refining of chromium-contained molten steel under a normal or reduced pressure; and is characterized by: determining, in sequence; a molten steel temperature during the refining through actual measurement or computation from a molten steel temperature before the refining and refining conditions; [C] and [Cr] concentrations during the refining through actual measurement or computation from molten steel components before the refining and refining conditions; a CO partial pressure PCO in an atmosphere during the refining from the total pressure P of the atmosphere, an oxygen gas supply rate and an inert gas supply rate, a Hilty's equilibrium temperature TH from said [C] and [Cr] concentrations and PCO; the difference &Dgr;T between said molten steel temp

Abstract: The present invention: solves the problems of hitherto disclosed technologies, such as insufficient suppression of the oxidation loss of [Cr] and the excessive erosion of refractories, in the decarburization-refining of chromium-contained molten steel under a normal or reduced pressure; and is characterized by: determining, in sequence; a molten steel temperature during the refining through actual measurement or computation from a molten steel temperature before the refining and refining conditions; [C] and [Cr] concentrations during the refining through actual measurement or computation from molten steel components before the refining and refining conditions; a CO partial pressure PCO in an atmosphere during the refining from the total pressure P of the atmosphere, an oxygen gas supply rate and an inert gas supply rate; a Hilty's equilibrium temperature TH from said [C] and [Cr] concentrations and PCO; the difference &Dgr;T between said molten steel temperatu

Abstract: The present invention provides a lade refining apparatus capable of suppressing skull deposition in a vacuum/decompression chamber and performing molten steel agitation, slag reforming and degassing efficiently, and a ladle refining method using the apparatus. The apparatus includes a vacuum/decompression chamber directly coupled to a top of a ladle, and is designed to have inert gas blown into the ladle for agitation of molten steel in the ladle. An inner diameter of a shaft of the vacuum/decompression chamber is not larger than an inner diameter of a top end of the ladle, but not smaller than a projected diameter of a bulging portion of a molten steel surface formed by the gas blown into the ladle.

Abstract: A direct smelting process for producing molten iron and/or ferroalloys from a metalliferous feed material is disclosed. The process is a molten bath based process that is carried out in a direct smelting vessel. The process includes the steps of supplying metalliferous feed material, carbonaceous material and fluxes into the vessel; smelting metalliferous feed material to molten iron in the molten bath; and injecting an oxygen-containing gas into the vessel to post-combust gases generated in the process. The process is characterised by controlling the level of molten metal in the vessel by adjusting the pressure in the vessel.

Abstract: An energy efficient, coal-based method and apparatus that are environmentally friendly which produce under pressure metallized/carbon product and molten metal directly from abundant coal or other carbonaceous material, and low cost fines (or ore concentrate) wherein the metal is devoid of gangue material and possesses the inherent advantage of retaining the heat for subsequent processing. This method and apparatus which are modular and highly integrated significantly reduce capital and operating costs; they also provide the capability selective placement of the reductant for the delivery of high levels of thermal energy input which leads to ease of desulflurization and high productivity. The technology herein disclosed is entirely closed and is applicable to various ores including ferrous and non-ferrous.

Abstract: The invention intends to provide a converter refining method capable of blowing molten steel having a low degree of superoxidation with high productivity and high yield. A first aspect resides in a pressurized converter steelmaking method for use in a top-and-bottom blowing converter, wherein a converter internal pressure P is set to a higher level than the atmospheric pressure, and a top-blown oxygen flow rate F and a bottom-blown gas flow rate Q are adjusted depending on changes of the converter internal pressure P. A second aspect resides in a pressurized converter steelmaking method for use in a top-and-bottom blowing converter, wherein a converter internal pressure P is set to a higher level than the atmospheric pressure during the whole or a part of a blowing period, and a top-blown oxygen flow rate F, a bottom-blown gas flow rate Q and the converter internal pressure P are changed depending on a steel bath carbon concentration C.

Abstract: The invention concerns a process for producing metal from metal ores, in particular crude or pig iron from iron ore, wherein the ore which contains metal oxides is brought into contact with a reducing gas which contains carbon and/or hydrogen from solid, carbon-bearing and/or hydrocarbon-bearing substances obtained at least partially from plastic waste. According to the invention, the carbon-bearing and/or hydrocarbon-bearing substances are injected in comminuted fluidized form as an agglomerate into the air flow in the hearth of the metallurgical shaft or pit furnace, in particular a blast furnace. The apparatus includes a first shut-off device that is closed when blockages of the plastic material occur in the transport conduit or the lance, a second shut-off device that is closed when hot air penetrates into the transport conduit and/or the lance by reverse flow, and a third shut-off device that is closed when compressed air is supplied to a lance for cooling.

Abstract: A method of operating a blast furnace enables substantial improvement of gas permeability and liquid permeability for stable operation of the blast furnace, involves packing the core section with solid high strength, carbonaceous blocks prior to ignition of the furnace. The carbon blocks resist wearing and high temperature reaction over very long periods of operating time, greatly stabilizing the furnace. Because of the improved stabilization, gas permeability and liquid permeability, a low grade solid reducing agent can be substituted for a quantity of the high quality coke normally used for operating the blast furnace and furthermore enables injection of pulverized coal at a rate of at least 200 Kg/ton-pig.

Abstract: A process of producing metal from a metal ore containing metal oxides includes the steps of: obtaining a reducing gas containing at least one of carbon and hydrogen from solid substances containing at least one of carbon and hydrocarbons; bringing the ore into reaction contact with the reducing gas in a metallurgical blast furnace; and injecting a comminuted, fluidized plastics material into a blast current in a hearth region of the blast furnace, the plastics material comprising an agglomerate including plastics particles having a particle size substantially between 1 mm and 10 mm.

Abstract: Method and apparatus for collecting valuable products, particularly zinc, from a zinc-containing substance such as electric furnace dust. A shaft type smelting reduction furnace has a packed bed of a carbonaceous solid reducing agent and has upper and lower tuyeres, and a zinc-containing substance is injected through tuyeres to reduce and vaporize zinc, which is directly contacted by a liquid coolant thereby forming a slurry, and the zinc product is collected from the slurry.

Abstract: In steel-making, there are conflicting processing requirements at different stages of the process. The method and apparatus of the invention creates different processing conditions at different stages of the process. Molten ferrous material (2) is stirred by bubbling a gas therethrough. A refractory ring (10) is first partially immersed in the molten steel within a substantially slag free portion of the surface of the molten ferrous metal to form a bounded substantially slag-free area. The molten steel is then heated by the introduction of exothermically reacting heating agents such as aluminium and oxygen through an oxygen gas line (7) and an aluminium delivery tube (9), respectively. The refractory ring (10) is then removed from the molten steel when the steel has reached a predetermined temperature and air is then excluded from the volume above the molten steel by placing a hood (16) over the ladle containing the molten steel. Sulphur is then removed from the steel.

Abstract: Method and apparatus for recovering free aluminum from a metal bearing dross containing free aluminum metal and oxides of the metal. Hot dross is collected from a hot dross source into a vessel, and the vessel is placed into a sealable storage container. The storage container is insulated to maintain heat generated by the hot dross within the interior of the storage container to maintain the dross at or near its temperature when first placed in the storage container. An inert gas is then introduced into the container to purge the container of all gasses other than the inert gas. The inert gas reduces thermiting of the hot dross and limits the cooling of the hot dross in order to maintain the hot dross at an elevated temperature while the hot dross remains in the storage container. The dross is then removed from the vessel and introduced dross into a dross processing device such as a furnace.

Abstract: The disclosure relates to a molten metal producing and refining method which does not damage the apparatus, realizes a stable and high second combustion rate, and is capable of effectively recovering heat generated by the second combustion. The method comprises introducing a metal-containing material, a carbonaceous material, a flux and O.sub.2 gas into a furnace. The carbon which dissolves into the metal bath in the furnace from the carbonaceous material is combusted with the O.sub.2 gas to generate heat and CO gas. The CO gas is subjected to the second combustion with the O.sub.2 gas to additionally generate heat, and the metal-containing material is melted and refined by both the generated heat and carbon. The method is characterized in that O.sub.2 gas or O.sub.2 -containing gas is blown into the furnace through large-diameter tuyeres installed near the bottom of the furnace and a part of the O.sub.

Abstract: Disclosed herein is a method for operating blast furnace, wherein, when charging coke and ore alternately from the furnace top to form alternate coke and ore layers for operation of a blast furnace, a coke layer is formed by charging coke of properties especially suitable for improvement of gas and liquid permeability of the coke layer to the central part thereof or an ore layer is formed by charging ordinary versatile type coke to the central part of the ore layer prior to formation thereof. The centrally charged coke forms a major part of the dead coke layer which is sequentially renewed under the cohesive zone of the blast furnace to maintain appropriate gas and liquid permeability of the dead coke layer, thereby enhancing the production efficiency and stability of the blast furnace operation while suppressing erosive wear of refractory walls of the furnace.