The present invention concerns a method of and a device for directly reducing fine-particle ore in a horizontal reactor with an ore-reducing gas and a heat vehicle, also a gas, in a fluidized bed. The ore-reducing vessel itself comprises a horizontal fluidized-bed reactor (1). The ore (F) is blown into it from below. The heated ore-reducing gas (A) is blown into the reactor through oncoming-gas floors (2). The heat needed for the endothermic reaction is supplied to the reactor at different temperatures through heat exchangers (3) and transferred to the bed. Heat is supplied counter to the ore-reducing gas. Fuel (B) in the form of gas is burned with air (C) to make the heat vehicle (D). The ore-reducing gas (A') is heated in downstream heat exchangers (5.1 to 5.3) before arriving in the three sections (1a, 1b, & 1c) of the reactor through the floors. Sponge iron (6) is removed and throat gas (E) extracted from a sponge-collecting section (1d).
A method and device are provided for direct reduction of ore fines in a wide range of particle size, the reducing agent being hydrogen placed in a fluidized bed gutter with a plurality of sequentially arranged chambers. The fluidization rate in the supply base is set so that a defined class of particle size remains in the chamber concerned where it will be submitted to a reduction process and that the finest particle size fraction is discharged from the chamber, then precipitated in a hot gas cyclone to solid material (or fines) and gas. The ore fines precipitated in the cyclone then reaches the following chamber. The gas from all the hot gas cyclones is fed by a collector to the pre-heater. After reduction in the chambers, the ore fines are conveyed in pressure vessels for submission to further processes.
In a process for the gas reduction of particulate oxide-containing ores, in particular iron-oxide-containing material, in the fluidized-bed process at a pressure of <5 bars, wherein the ore by aid of a reducing gas produced from coal is heated, optionally also pre-reduced, in a fluidized-bed reactor (1) designed as a pre-heating stage (5), subsequently is reduced to sponge iron in at least one fluidized-bed reactor (2, 3) designed as a reduction stage (7, 8), the reducing gas via a reducing-gas feed duct (12) or reducing-gas duct (13) being conducted from the reduction stage (7, 8) to the pre-heating stage (5) in the opposite direction of the material to be reduced and conducted from stage to stage, and being drawn off as an export gas after purification, heat is supplied to the reducing gas fed to the reduction stage (7, 8) and/or pre-heating stage (5), namely by combustion, together with oxygen and/or air, of a portion of the reducing gas provided for the gas reduction in the reduction stage (7, 8) and/or the pre-heating stage (5).
Apparatus (1) and process for treating particulate material or powder (33) of a size capable of being fluidized in a retort (31) mounted for rotation on a pair of end axles (18, 41). Retort (31) is mounted on a tilt frame (5) for tilting movement in a vertical plane. Gas conduits (18A, 18B) are mounted within an axle (18) for the supply and exhaust of gas for retort (31). A conduit (55) mounted within the other axle (41) permits particulate material to be passed into or out of the retort (31) as shown in FIG. 1B. A removable injection assembly (90, FIG. 10) is utilized for the injection of additional particulate material. A removable sampling assembly (95, FIG. 11) is utilized for removing a sample of the particulate material from the retort (31). As the retort (31) is rotated, particles of the particulate material are constantly intermingled with each other and the walls of the retort (31). Microwave energy as shown in FIGS. 13-14 may be utilized to heat or dry materials within the retort (31). A plenum (105H) and a permeable membrane (105R) may be provided in an end wall (105B) of a retort (105A) as shown in FIG. 17.
Methods and apparatus for the reduction into metallic iron of iron-oxides-containing particles having a broad range of sizes. Particles, typically within a broad range of sizes of about 0.1 mm to about 50 mm, are reduced by contact with a hot reducing gas, preferably from a horizontal gas distributor which defines the bottom of the reduction zone by supplying a uniform upflow of gas mainly composed of hydrogen (and/or carbon monoxide) within a temperature range of 650.degree. C. to 1050.degree. C. and at a velocity of about 0.5-0.7 m/s to fluidize at least some of the particles of a size of about 1.0 mm or less (when present). The reducing gas flows upwardly through a descending moving bed of coarser particles and forms thereabove a fluidized bed of fines, all in a single chamber in a reduction reactor, where the particles charged to the reactor are fed into the fluidized bed, preferably at the lower portion thereof at or near the interface with the moving bed, and the lighter reduced fluidized fines are withdrawn from the reactor from the upper portion of the fluidized bed. The spent reducing gas from the reactor passes through at least one cyclone separator with the fines entrained therein being normally returned to the reactor or optionally being subjected to a lower velocity fluidization in a separate reduction chamber of the reactor.
The present invention describes a method and apparatus for the reduction into metallic iron of iron-oxides-containing particles having a broad range of sizes. Particles, preferably within a broad range of sizes smaller than about 3.2 mm, are reduced by contact with a hot reducing gas, preferably mainly composed of hydrogen and within a temperature range of 700 to 750.degree. C. The reducing gas flows through a descending moving bed of coarser particles and forms an ascending fluidized bed of fines, all in a single reduction reactor, where the particles charged to the reactor are fed into the lower portion of the fluidized bed and the reduced fines are withdrawn from the reactor from the upper portion of the fluidized bed.
