Hylsa, S.a. De C.v.

Hylsa, S.a.

Danieli & C. Officine Meccaniche S.p.a.

Hyl Technologies S.a. De C.v.

Jorge O Becerra-Novoa

Ricardo Viramontes-Brown

Alessandro Martinis

Enrique R Martinez-Vera

Marco Aurelio Flores-Verdugo

Ronald Victor Manuel Lopez-Gomez

Jose J Garza-Ondarza

Raul Gerardo Quintero-Flores

Juan Celada-Gonzalez

Andrea Tavano

Maria Teresa Guerra-Reyes

Federico E Carranza-Almaguer

Enrique R Martinez Vera

Enrique R Vera

Fernando R Webb-Balderas

Francisco Cantu-Hernandez

A direct reduction process producing DRI from iron oxide particles by reduction at a about 750&#xb0; C. with a reducing gas mainly Hand CO, that also includes CO, Hand 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 COremoval unit and then with the second hydrocarbon-containing make-up gas passes through a heater yielding a hot CO-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.

Direct reduction process with improved product quality and process gas efficiency

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.

Integrated steel plant with production of hot or cold DRI

So as to provide a container that is inexpensive to manufacture and that promotes a uniform flow of particulate bulk materials therethrough, a vessel is suggested comprising at least two wall segments having a generally downwardly converging wall defining a vertical axis for the vessel, a first upper segment being vertically arranged above a second lower segment, each one of the wall segments having an upper edge and a lower edge, the perimeter of the upper edge of the second lower wall segment being larger than the perimeter of the lower edge of the first upper wall segment the lower edge of the first upper wall segment and the upper edge of the second lower wall segment being positioned proximate to each other and cooperating to provide an enlargement of the cross-sectional area of the volume occupied by the particulate solid material.

Vessel for enabling a uniform gravity driven flow of particulate bulk material therethrough, and direct reduction reactor incorporating same

In method and apparatus for producing iron and steel from iron cores largely composed of iron oxides, wherein a direct reduction process is used to produce a solid particulate intermediate product, generally known as sponge Iron or Direct Reduced Iron (DRI); pneumatically conveying large iron-bearing particles, such as pelletized iron ore or particularly DRI, in a closed transport pipe, eg. from the reduction reactor of the direct reduction process to the metallurgical furnaces where liquid iron or steel are produced, for example electric arc furnaces, induction furnaces, basic oxygen furnaces, etc. or to a briquetting press to form DRI briquettes, or simply to a silo or storage bin, or in general to a subsequent processing step for said DRI. When the carrier gas is recirculated for reuse, surprisingly air can be a preferred source of such gas, especially for reactive hot DRI. This method has a superior efficiency and productivity and reduces the overall energy consumption relative to currently used DRI steelmaking plants. By using pneumatic conveyors, elements of the plant may be arranged side by side rather than one on top of the other, whereby the overall height of the plant may be reduced.

Apparatus for the pneumatic transport of large iron-bearing particles

In a method of producing iron and steel, from iron ores largely composed of iron oxides, wherein a direct reduction process is used to produce a solid particulate intermediate product, generally known as sponge iron or Direct Reduced Iron (DRI); pneumatically conveying the DRI in a closed pipe from the reduction reactor of the direct reduction process to the metallurgical furnaces where liquid iron or steel are produced, for example electric arc furnaces, induction furnaces, basic oxygen furnaces, etc. or to a briquetting press to form DRI briquettes, or simply to a silo or storage bin, or in general to a subsequent processing step for said DRI. When the carrier gas is recirculated for reuse, surprisingly air is preferred as the source of such gas, especially for reactive hot DRI. This method has a superior efficiency and productivity and reduces the overall energy consumption relative to currently used DRI steelmaking plants. This is also applicable to pneumatic delivery of cold (or hot) ore to the reduction reactor.

Method for the pneumatic transport of large iron-bearing particles

A method and apparatus for the gaseous reduction of particulate iron ores, wherein the ore or is fed to a vertical moving bed direct reduction reactor, reduced therein, and discharged as hot sponge iron. The ore is charged to the top portion of the reduction zone of the furnace wherein the bed of particles which descend by gravity is reduced by a hot reducing gas largely composed by carbon monoxide and hydrogen. The hot reducing gas is divided in two portions, a first portion which flows upwardly through the reduction zone to reduce the ores therein, and a second portion which flows downwardly through a lower discharge zone to maintain the bed at a suitable temperature level. Finally, the product sponge iron is discharged from the bottom portion of the discharge zone of the furnace and conveyed, for example, to be melted in an electric arc furnace or to be briquetted in a briquetting machine coupled to the reduction reactor.

Method and apparatus for the production of hot direct reduced iron

Start-up method for an iron ore direct reduction process, where in the steady-state process the reducing gases are produced by steam reformation of natural gas catalyzed within the reducing zone of the reduction vessel by the reduced ore present therein. During established steady-state operation, a process gas stream is circulated in a reducing gas loop comprising the reduction vessel, a gas heater, and units to remove H.sub.2 O and CO from the gas circulating in said loop. Natural gas and water are fed directly to the reducing gas loop as make-up reactants for the reformation. At plant start-up there is a complete absence of metallic iron to catalyze the reformation reaction at any temperature, and a complete absence of H.sub.2 or CO so no effective reduction is possible to produce the needed metallic iron. In a multi-stage start-up, the reduction vessel is first charged with iron ore and pressurized by introducing natural gas to said loop. Simultaneously, the temperature is raised to the range of 400.degree. to 600.degree. C. The natural gas cracks, producing a small amount of H.sub.2 and some carbon soot. Second, the temperature is further increased, and injection of water is begun to prevent further carbon deposition, to promote the production of H.sub.2, and to avoid H.sub.2 consumption; until 3% to 8% by volume of H.sub.2 accumulates. Third, at about 750.degree.-820.degree. C., water injection is interrupted favoring the accumulation of hydrogen until a concentration of about 65% is achieved while the temperature of the process gas stream reaches its steady-state value of about 950.degree. C. Fourth, water is again injected to promote the reforming of make-up natural gas within the reduction vessel and all process feeds are adjusted to their steady-state values.

Start-up method for a direct reduction process without an external

A method and apparatus for the direct gaseous reduction of iron ore to sponge iron at an elevated temperature suitable for hot briquetting, wherein a hot reducing gas is circulated upwardly through a descending body of iron ore and a make-up reducing gas stream is added to the circulating gas stream. A sponge iron product having a predetermined desired degree of carburization in the range 0.5% to 4% is obtained by adding a controlled flow of natural gas or other methane-containing gas to said make-up gas stream or to said circulating gas stream.

Method for producing hot sponge iron by introducing hydrocarbon for

A process for the gaseous reduction of iron ore to sponge iron in a vertical shaft, moving bed reactor wherein a hot gaseous mixture of hydrogen and a carbon monoxide is used to reduce the ore. It has been found unnecessary to use the external catalytic reformer of prior art processes to reform the methane and other hydrocarbon constituents of the natural gas commonly used as a source of gaseous reductants. By establishing a reducing gas recycle loop to which make-up natural gas and steam are fed in the proper proportions, the product sponge iron in the reactor can be used to catalyze hydrocarbon reformation, provided that the carbon content of the recycled gas is maintained low by removing carbon dioxide therefrom. Where pure methane is employed, steam/methane molar ratios within the preferred range of 1.4:1 to 2.2:1 are used.

Method of reducing iron ore

A method of operating a vertical moving bed reduction reactor for reducing iron ore to sponge iron and having a reduction zone in the upper portion thereof and a cooling zone in the lower portion thereof to obtain a desired degree of metallization of the reduced ore in said reduction zone and a desired degree of carburization in said cooling zone which comprises supplying to said reactor a predetermined flow of reducing gas comprising carbon monoxide and hydrogen and, varying the ratio of reducing gas flow to said reduction zone to the reducing gas flow to said cooling zone to vary at least one of the amount of metallization attained in said reduction zone and the amount of carburization attained in said cooling zone, maintaining the carbon dioxide concentration in said reduction zone at a value which yields the desired degree of metallization therein and maintaining the carbon dioxide concentration in said cooling zone at a value which yields the desired degree of carburization in said cooling zone.

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Apodaca, Mexico

Jorge O Becerra-Novoa