Abstract: A method for producing direct reduced iron having increased carbon content, comprising: providing a carbon monoxide-rich gas stream; and delivering the carbon-monoxide-rich gas stream to a direct reduction furnace and exposing partially or completely reduced iron oxide to the carbon monoxide-rich gas stream. The carbon monoxide-rich gas stream is delivered to one or more of a transition zone and a cooling zone of the direct reduction furnace. Optionally, providing the carbon monoxide-rich gas stream comprises initially providing one of a reformed gas stream from a reformer and a syngas stream from a syngas source. Optionally, the carbon monoxide-rich gas stream is derived from a carbon monoxide recovery unit that forms the carbon monoxide-rich gas stream and an effluent gas stream. Optionally, the method still further includes providing a hydrocarbon-rich gas stream to one or more of a transition zone and a cooling zone of the direct reduction furnace.

Abstract: A method for producing high carbon content metallic iron using coke oven gas, including: dividing a top gas stream from a direct reduction shaft furnace into a first top gas stream and a second top gas stream; mixing the first top gas stream with a coke oven gas stream from a coke oven gas source and processing at least a portion of a resulting combined coke oven gas stream in a carbon dioxide separation unit to form a synthesis gas-rich gas stream and a carbon-dioxide rich gas stream; delivering the synthesis gas-rich gas stream to the direct reduction shaft furnace as bustle gas; using the carbon-dioxide rich gas stream as fuel gas in one or more heating units; and delivering the second top gas stream to the direct reduction shaft furnace as bustle gas.

Abstract: Production method and apparatus for direct reduced iron (DRI), a.k.a sponge iron, by contacting iron oxides with recycled and regenerated hot reducing gases containing H2 & CO2. This invention decreases uncontained emission of CO2 to the atmosphere from combustion of carbon-bearing fuels in the reducing-gas heater by substituting, at least partially, a gas mainly comprising hydrogen in lieu of the usual carbon-bearing fuels. The hydrogen fuel stream, depleted of CO2 by means of a physical gas separation unit (which can be a PSA/VPSA type adsorption unit, a gas separation membrane unit or a combination of both such units) is derived from at least a portion of regenerated reducing gases being recycled to the reduction reactor. The derived hydrogen fuel stream is combusted in the reducing gas heater and/or other thermal equipment in the reduction plant, thus decreasing the CO2 emissions directly to the atmosphere.

Abstract: Method for the direct reduction of mineral iron inside a vertical reduction furnace (10) of the type with a gravitational load, wherein the reducing gas flows in counter-flow with respect to the material introduced into the furnace, comprising the following steps: the mineral iron is fed from above into the furnace (10), a mixture of high temperature gas consisting of reducing gas based on H2 and CO is injected, and the reduced mineral is removed from the furnace (10). The mixture of gas is introduced into at least a zone (14) of the furnace (10) and consists of the process gas, which emerges from the same furnace, and of additional gas arriving from an outside reforming circuit.

Abstract: An improved method and apparatus for increasing the productivity of a direct reduction process in which iron oxide is reduced to metallized iron by contact with hot reducing gas; comprising the steps of: a) providing a first hot reducing gas consisting essentially of CO and H2; b) providing additional reducing gas by reaction of a gaseous or liquid hydrocarbon fuel with oxygen; c) mixing the first hot reducing gas with the additional reducing gas to form a reducing gas mixture; d) enriching the reducing gas mixture by the addition of a gaseous or liquid hydrocarbon; e) injecting oxygen or oxygen-enriched air into the enriched mixture; and f) introducing the enriched mixture into an associated direct reduction furnace as reducing gas.

Abstract: A method and apparatus for increasing the productivity of an existing direct reduction iron (DRI) plant without increasing its reformer capacity existing in the plant. This object is achieved by not only recycling some effluent gas of the reduction reactor to the gas reformer (with natural gas or the like added with an oxidant as make up gas), but also recycling an additional portion of the effluent gas with added natural gas and an oxygen containing stream directly to the reducing gas stream exiting the reformer prior to or as part of its introduction to the reduction reactor, thereby providing additional reducing agents and increasing the reducing capacity of the plant. The oxygen containing stream is preferably added to the recycled reducing gas without preheating. Any excess or purged effluent gas is as usual burned as fuel.

Abstract: Gravitational type furnace for the direct reduction of mineral iron comprising a median reaction zone (14) in which the reactions to reduce the mineral iron occur, means (11) to feed the mineral iron to said reaction zone (14), means (18) to introduce a mixture of reducing gas into said reaction zone (14) and means (15) to discharge the reduced metal iron, said discharge means comprising at least two extremities (15a-15c), shaped like a cone or a truncated cone, with the taper facing downwards, each of which being provided with a corresponding lower aperture (16a-16c) through which said reduced metal iron can be selectively discharged in a controlled and independent manner.

Abstract: A method and apparatus for producing DRI, prereduced materials, or the like, utilized in the steelmaking industry, where hydrogen contained in the gas stream purged from the reduction reactor is separated (preferably by means of a PSA system) and recycled to said reduction reactor. The productivity of the reduction plant is increased by using the separated hydrogen as a chemical reductant in the reactor, instead of using it as fuel. This is particularly useful in upgrading existing DRI production plants.

Abstract: Method and apparatus for the production of prereduced iron ore, Direct Reduced Iron (DRI), or the like, in an ironmaking plant wherein the reducing gas utilized in the chemical reduction of iron oxides is generated from natural gas within the reduction reactor system by reforming the hydrocarbons with such oxidants as water and oxygen inside the reduction reactor which under steady state conditions contains metallic iron which acts as a reformation catalyst. The amount of carbon in the DRI can be reliably controlled by modifyng the relative amounts of water, carbon dioxide and oxygen in the composition of the reducing gas fed to the reduction reactor. The amount of carbon in the DRI is controlled by the amount of water in the reducing gas fed to the reduction reactor while the addition of oxygen provides the energy necessary for such DRI carburization.

Abstract: A method for direct reduction of oxides includes the steps of: providing a reduction zone for direct reduction of oxides and a gas reforming zone communicating with the reduction zone; feeding metal oxides to the reduction zone; feeding a gas mixture comprising methane and an oxygen source to the gas performing zone to provide a reformed gas comprising hydrogen and carbon monoxide; contacting the oxides and the reformed gas in the reduction zone to provide a reduced metal and a top gas; and treating the top gas so as to provide the gas mixture.

Abstract: A method for modifying existing direct reduction processes and retrofitting existing direct reduction facilities so as to increase the capacity of the facilities without the need for increasing the capacity of external reformers associated with the existing facilities comprises mixing preheated air with the reformed reducing gas produced in the external reformers and containing said mixture with excess natural gas in a reduction-reaction zone of the direct reduction reactor.

Abstract: A process for converting iron oxide to iron carbide at low pressure includes providing a reforming-reduction-carburizing reactor wherein a feed gas is reformed by contact with the iron oxide materials, the iron oxide material is reduced and thereafter contacted with a carburizing agent so as to carry out the conversion of iron oxide to iron carbide in the reactor.

Abstract: A process for the gaseous reduction of iron ore to sponge in a vertical shaft, moving bed reactor wherein a hot gaseous mixture of hydrogen and carbon monoxide generated by the internal steam reformation of gaseous hydrocarbon(s), preferably methane or natural gas, is used to reduce the ore without the need for any external catalytic reformer. A reducing gas recycle loop is established to which hydrocarbon and reclaimed waste hot water are fed in the proper proportions as the reducing gas make-up source with the sponge iron produced in the reduction reactor being used to catalyze hydrocarbon reformation, and with the carbon content of the recycled gas being maintained low by removing carbon dioxide therefrom.

Abstract: A process for the direct reduction of metal oxides containing iron to obtain a DRI metallized iron product comprises feeding heavy hydrocarbon oil under controlled conditions to a cracking zone upstream of the reduction reactor so as to form a cracked product rich in CH.sub.4 and thereafter feeding said cracked product directly to the reaction zone wherein a reformed reducing gas rich in H.sub.2 and CO is formed and contacted with said iron oxide material thereby effecting reduction of said iron oxide material in the reaction zone.

Abstract: The present invention relates to a process for the production of liquid steel from iron containing metal oxides and, more particularly, a process for the direct production of iron-containing metal oxides wherein the hot discharge of direct reduced iron (DRI or sponge iron) is fed to a melting furnace with the process gases from the direct production furnace for refining the DRI to liquid steel.

Abstract: A process for the direct reduction of iron-containing metal oxides to obtain iron is disclosed in which a reformed reduction gas rich in H.sub.2 and CO and having an oxidation degree in the range of from about 0.30 to about 0.35 is formed and reduction is carried out simultaneously in a single reaction zone of a reduction reactor. The reformed reduction gas is formed using a highly endothermic reaction during which a mixture of heated natural gas, recycled top gas and air, preferably oxygen enriched air, is placed into contact with heated surfaces of DRI metallized iron in the reaction zone. The resulting reformed reducing gas consists essentially of from about 45% to about 48% hydrogen, from about 32% to about 34% carbon monoxide, from about 2% to about 4% carbon dioxide, from about 1% to about 3% methane, from about 14% to about 16% nitrogen and from about 1% to about 3% water vapor.