Abstract: A vessel for containing direct reduced iron (DRI), such as a reactor for the production of DRI, a bin or a hopper or other container for storing or feeding DRI to melting furnaces or briquetting machines, includes at least an upper zone, defined by a first lateral wall having a substantially cylindrical tubular shape, and a discharge zone, positioned below the upper zone and defined by a second lateral wall having a substantially truncated cone shape converging toward a lower discharge aperture. The second lateral wall has an internal surface at least partly lined by an internal lining.

Abstract: A method and apparatus for producing direct reduced iron using a pre-treated make-up gas as a reducing agent in a direct reduced iron reactor are provided. The method involves pre-treating a stream of make-up gas containing heavy hydrocarbons by subjecting the stream to low temperature adiabatic reforming at a temperature between 300° C. and 600° C., prior to using the stream of make-up gas as a reducing agent for producing direct reduced iron. The method also involves adjusting the humidity content of the stream of make-up gas after the low temperature adiabatic reforming by bypassing the stream to selectively split it into a first part of the stream of make-up gas and a second part of the stream of make-up gas, subjecting the first part to water separation, and then mixing the first part with the second part to obtain a reducing stream to be sent to direct reduced iron production.

Abstract: Producing direct reduced iron (DRI) having chemically-combined carbon includes providing DRI at a temperature above 400° C., providing a first gas stream including hydrogen and carbon monoxide, passing the first gas stream through a methane forming process to yield a second gas stream containing a higher concentration of methane than the first gas stream; and contacting the second gas stream with the DRI. A system for producing the DRI includes a vessel for containing DRI at a temperature above 400° C., a methane forming reactor containing a catalyst bed for producing methane from a first gas stream containing hydrogen and carbon monoxide, a first conduit to feed a gas stream including hydrogen and carbon monoxide to the methane forming reactor, and a second conduit to feed the second gas stream to the vessel containing the DRI.

Abstract: Producing direct reduced iron (DRI) having chemically-combined carbon includes providing DRI at a temperature above 400° C., providing a first gas stream including hydrogen and carbon monoxide, passing the first gas stream through a methane forming process to yield a second gas stream containing a higher concentration of methane than the first gas stream; and contacting the second gas stream with the DRI. A system for producing the DRI includes a vessel for containing DRI at a temperature above 400° C., a methane forming reactor containing a catalyst bed for producing methane from a first gas stream containing hydrogen and carbon monoxide, a first conduit to feed a gas stream including hydrogen and carbon monoxide to the methane forming reactor, and a second conduit to feed the second gas stream to the vessel containing the DRI.

Abstract: A direct reduction process producing DRI from iron oxide particles by reduction at a about 750° C. with a reducing gas mainly H2 and CO, that also includes CO2, H20, and methane, a the reduction reactor and the top gas effluent from the reduction reaction after cooling/scrubbing is split. The resulting first top gas portion with a first hydrocarbon-containing make-up gas passes through a catalytic reformer yielding an improved hot reducing gas first effluent. The second top gas portion passes through a CO2 removal unit and then with the second hydrocarbon-containing make-up gas passes through a heater yielding a hot CO2-lean recycle reducing gas second effluent. The first and second effluents are fed to the reducing zone of the reduction reactor as the reducing gas reactant. The flow rate of at least the second of the two make-up gases is regulated to control the carbon content of the DRI produced.

Abstract: A sealing device for a vessel to achieve a fluid-tight seal in an aperture made in the lateral wall of said vessel, into which aperture a shaft is inserted. The sealing device comprises first sealing means disposed in contact with the shaft in the zone of said aperture, and second sealing means, comprising a containing body and a flexible connection element. The first sealing means comprise a plurality of sealing rings, disposed coaxial to the shaft and in contact with the latter, and a containing tube to contain the sealing rings. The lateral wall of the vessel comprises an interface flange. A closing flange is connected to the interface flange and to a flanged end of the containing body by means of attachment means and is positioned in contact with the containing tube and with the flexible connection element to keep the first sealing means in a determinate axial position with respect to the shaft.

Abstract: Direct reduction process and plant for producing DRI comprising a reduction reactor and at least one reducing gas heater typically comprising a convective heating section and a radiant heating section for raising the reducing gas temperature to a level adequate for iron oxides reduction to metallic iron, typically above 850° C., wherein the reducing gas fed to the reduction reactor comprises a stream of reducing gas recycled from the reduction reactor and a make-up stream of coke oven gas containing carbon compounds which may form carbon deposits in the heating path of said heater, namely BTX and other complex carbon compounds. The heater is provided with means for feeding oxidizing agents, for example steam, steam and air and/or oxygen at predetermined heating tubes successively for eliminating the carbon deposits which may form inside the heating tubes of said heater without interrupting the operation of the plant.

Abstract: A blast furnace system is used wherein the coke rate is decreased by recycling upgraded top gas from the furnace back into its shaft section (which upgraded top gas is heated in a tubular heater prior to being recycled). The top gas, comprising CO, CO2 and H2, is withdrawn from the upper part of the blast furnace; cooled and cleaned of dust, water, and CO2 for increasing its reduction potential and is heated to a temperature above 850° C. before being recycled thus defining a first gas flow path used during normal operation of the blast furnace. Uniquely, a second gas flow path for continued circulation of top gas selectively through the heater and a cooler during operation interruptions of the blast furnace allows time for gradual controlled cool down of the heater in a manner to avoid heat-shock damage to the tubular heater.

Abstract: A process for producing DRI from iron ores, utilizing a gas produced from fossil fuels, containing sulfur compounds and BTX, heating said gas in a heater, preferably a regenerator, wherein heat is transferred from a previously-heated solid material to the gas. Flowing the hot gas through a bed of DRI particles, iron oxides or other equivalent material, outside of the reduction reactor, where said material adsorbs sulfur compounds and destroys BTX. The resulting gas, free from sulfur compounds and BTX, is combined with a reducing gas stream from the reduction reactor after H2O and CO2 is at least partially removed for regenerating its reducing potential, with or without undergoing previous cleaning, is used for producing DRI. One inventive embodiment comprises producing DRI at high temperature giving advantageously higher productivity and energy savings when using hot DRI in an electric arc furnace lowering the capital and operational costs of steelmaking.

Abstract: Method and apparatus to determine the skin-temperature of heat-exchange tubes and to prevent overheating of the heat-exchange tubes in a process gas heater (where extreme conditions prevent obtaining sufficiently-accurate direct thermocouple or pyrometric measurement to reliably prevent such overheating) by calculating the maximum skin temperature of heat-exchange tubes using preferably real-time calculation of the overall heat flux through the walls of the heat-exchange tubes with preferably real-time values of gas composition and gas temperature at the inlet and at the outlet of the tubes to calculate the overall transferred heat; and by periodically measuring the temperature of the gas flowing through each of the heat-exchange tubes, and using the measured gas temperatures for calculating the skin-temperature of all tubes, or of a tube selected for the highest gas temperature using the equation: Q = 2 ? ? ? ? L ? ( Ts - Tg ) / ( ln ? ro ri Km ) .

Abstract: The present invention concerns a method and an apparatus for producing DRI (Direct Reduced Iron) utilizing a high-oxidation reducing gas containing carbon monoxide and hydrogen, derived directly or indirectly from the gasification of hydrocarbons or coal, with a high content of oxidants (H2O and CO2). The invention provides a more efficient method and plant comprising a reactor in which particulate material of iron ore comes into contact with a high temperature reducing gas to produce DRI, with lower investment and operating costs, avoiding the need for a fired heater for the reducing gas fed into the reduction reactor. The reducing gas is heated to a temperature above 700° C. in two steps, a first step at a temperature below about 400° C.

Abstract: A direct reduction process producing DRI from iron oxide particles by reduction at a about 750° C. with a reducing gas mainly H2 and CO, that also includes CO2, H20, and methane, a the reduction reactor and the top gas effluent from the reduction reaction after cooling/scrubbing is split. The resulting first top gas portion with a first hydrocarbon-containing make-up gas passes through a catalytic reformer yielding an improved hot reducing gas first effluent. The second top gas portion passes through a CO2 removal unit and then with the second hydrocarbon-containing make-up gas passes through a heater yielding a hot CO2-lean recycle reducing gas second effluent. The first and second effluents are fed to the reducing zone of the reduction reactor as the reducing gas reactant. The flow rate of at least the second of the two make-up gases is regulated to control the carbon content of the DRI produced.

Abstract: Direct reduction process and plant for producing DRI comprising a reduction reactor and at least one reducing gas heater typically comprising a convective heating section and a radiant heating section for raising the reducing gas temperature to a level adequate for iron oxides reduction to metallic iron, typically above 850° C., wherein the reducing gas fed to the reduction reactor comprises a stream of reducing gas recycled from the reduction reactor and a make-up stream of coke oven gas containing carbon compounds which may form carbon deposits in the heating path of said heater, namely BTX and other complex carbon compounds. The heater is provided with means for feeding oxidizing agents, for example steam, steam and air and/or oxygen at predetermined heating tubes successively for eliminating the carbon deposits which may form inside the heating tubes of said heater without interrupting the operation of the plant.

Abstract: A blast furnace system is used wherein the coke rate is decreased by recycling upgraded top gas from the furnace back into its shaft section (which upgraded top gas is heated in a tubular heater prior to being recycled). The top gas, comprising CO, CO2 and H2, is withdrawn from the upper part of the blast furnace; cooled and cleaned of dust, water, and CO2 for increasing its reduction potential and is heated to a temperature above 850° C. before being recycled thus defining a first gas flow path used during normal operation of the blast furnace. Uniquely, a second gas flow path for continued circulation of top gas selectively through the heater and a cooler during operation interruptions of the blast furnace allows time for gradual controlled cool down of the heater in a manner to avoid heat-shock damage to the tubular heater.

Abstract: A blast furnace where coke is combusted with oxygen, instead of air, and where a top gas comprising CO, CO2, H2, and without excess nitrogen is withdrawn from the upper part of the blast furnace, cleaned of dust, the H2/CO volume ratio adjusted to between 1.5 to 4.0 in a water shift reactor, water and CO2 are removed (increasing its reduction potential), heated to a temperature above 850° C. and fed back to the blast furnace above where iron starts melting (thereby increasing the amount of metallic iron reaching the dead-man zone and decreasing the amount of coke used for reduction). Also carbon deposit problems caused by heating the CO-containing recycled gas are minimized by on-line cleaning of the heater tubes with steam without significantly affecting the reduction potential of the recycled reducing gas.

Abstract: An integrated steelmaking plant for merging continuous operation of a reduction reactor producing hot DRI with the batch operation of a DRI melting furnace(s). The reactor produces hot DRI for a DRI melting furnace or cold DRI continuously even when the DRI production exceeds the DRI consumption rate of the furnace or suffers long-term operational delays. The reduction reactor has a DRI cooling zone therein which is selectively operable for cooling DRI when the hot DRI produced in the reactor can't all be consumed by the DRI melting furnace and when the capacity of the DRI bin feeding the melting furnace is insufficient to accumulate additional hot DRI. No separate DRI cooling vessel plus its gas compressor and gas cooling-cleaning system is needed, thus decreasing capital and operational costs. This also permits a flexible and modular construction and operation of a steelmaking plant with high or low pressure reduction reactors.

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: A process for producing direct reduced iron (DRI) from iron ores, utilizing a gas produced from fossil fuels, particularly coal, containing sulfur compounds and BTX, wherein said gas is heated in a gas heater, preferably of the regenerative type, wherein heat is transferred from a previously-heated solid material to the gas produced from coal. The hot gas is caused to flow through a bed of DRI particles, iron oxides or other equivalent material, outside of the reduction reactor, where said material adsorbs sulfur compounds and the BTX are destroyed. The gas resulting from this treatment, free from sulfur compounds and BTX, is combined with a reducing gas stream withdrawn from the reduction reactor after H2O and CO2 have at least partially have been removed for regenerating its reducing potential, with or without undergoing a previous cleaning treatment, is used for producing DRI.

Abstract: A steelmaking plant including a pressurized direct reduction reactor for continuous production of hot direct reduced iron with a batch-melting furnace and a standby cooler, all three being capable of being situated side-by-side, with such DRI being able to be alternatively fed to the furnace or to the cooler. The furnace is selectively charged through a diverter valve by a pneumatic transport system with the hot DRI being entrained in a carrier gas fed into a receiving bin (having an upper DRI/gas disengagement space and a lower DRI buffer portion). A pressurized charge of the DRI accumulated in such disengaging/buffer bin is periodically fed down into a dosing/depressurization bin which in turn depressurizes the DRI and feeds a batch of DRI down into the furnace. Upon sensing that the buffer portion is full, the DRI is then pneumatically diverted to the cooler, such as during furnace maintenance shut down.

Abstract: The present invention concerns a method and an apparatus for producing DRI (Direct Reduced Iron) utilizing a high-oxidation reducing gas containing carbon monoxide and hydrogen, derived directly or indirectly from the gasification of hydrocarbons or coal, with a high content of oxidants (H2O and CO2). The invention provides a more efficient method and plant comprising a reactor in which particulate material of iron ore comes into contact with a high temperature reducing gas to produce DRI, with lower investment and operating costs, avoiding the need for a fired heater for the reducing gas fed into the reduction reactor. The reducing gas is heated to a temperature above 700° C. in two steps, a first step at a temperature below about 400° C.