Abstract: A method and an apparatus for the gaseous reduction of particulate iron ores is disclosed, wherein the reduced ore, commonly called DRI (Direct Reduced Iron) or sponge iron, is treated in a vertical shaft moving bed furnace and discharged from said furnace in solid particulate form at high temperature, e.g. above 500.degree. C. The shaft furnace is of the type wherein a bed of particles descends by gravity through said furnace which has an upper section where ore pellets, lumps, or the like are reduced by reaction with a hot reducing gas, and a lower section of a downwardly tapering, preferably, in a generally conical shape, which converges to an outlet discharge orifice of smaller cross sectional area than the rest of said furnace.

Abstract: A rotary valve adapted to be used in regulating the flow of a particulate material comprises a casing with inlet and outlet conduits and a rotor mounted for rotation about a horizontal axis in the casing. The rotor has a ring of partially closed pockets to meter the particulate material passing through the valve and its periphery is spaced inwardly from the interior of the casing an amount sufficient to prevent squeezing and disintegration of the particulate material between the rotor and inlet conduit. A baffle prevents particulate material from flowing downwardly in the space between the rotor and casing at the up-turning of the rotor.

Abstract: A rotary valve adapted to be used in regulating the flow of a particulate material comprises a casing with inlet and outlet conduits and a rotor mounted for rotation about a horizontal axis in the casing. The rotor has a ring of open and closed pockets to meter the particulate material passing through the valve and its periphery is spaced inwardly from the interior of the casing an amount sufficient to prevent squeezing and disintegration of the particulate material between the rotor and inlet conduit. A baffle structure is provided to prevent particulate material from flowing downwardly in the space between the rotor and casing at the up-turning of the rotor.

Abstract: A method for the batchwise reduction of iron ore to sponge iron in a multiple unit reactor system is disclosed in which (a) separate fixed beds of iron-bearing material are simultaneously treated in at least one cooling reactor and at least two reduction reactors, (b) a reducing gas composed largely of carbon monoxide and hydrogen is used to cool the iron-bearing material in said cooling reactor and thereafter to reduce the iron-bearing material in said reduction reactors, (c) a stream of said reducing gas is caused to pass through the fixed bed of iron ore in said cooling reactor and then cooled and (d) a portion of the cooled effluent reducing gas from said cooling reactor is recycled thereto, the improvement which comprises causing the remainder of the cooling reactor effluent gas to be fed to said reduction reactors and to flow in parallel through the fixed beds of metal-bearing material in said reduction reactors, and heating the reducing gas fed to said reduction reactors before it enters said reactors

Abstract: An improvement in a method for the batchwise gaseous reduction of iron ore to sponge iron in a multiple unit reactor system including a cooling reactor and a series of reduction reactors. Reduction is effected with a gas composed largely of carbon monoxide and hydrogen generated by reforming a mixture of steam and natural gas or other gaseous hydrocarbons at an elevated temperature. The reducing gas pressure drop through the system is decreased by using an out-of-line cooling reactor and cooling gas loop, thereby making it feasible to use three or more reduction reactors in series and thus enhance the efficiency of utilization of the reducing gas. Also the use of an out-of-line cooling reactor permits independent control of both the gas flow rate and gas composition in the cooling loop.

Abstract: A method and apparatus for measuring and controlling the percentage reduction of iron ore in a vertical shaft, moving bed, gaseous reduction reactor. Reducing gas comprising hydrogen, methane, carbon monoxide and carbon dioxide is fed from a source of such gas to the bottom of the reduction zone of the reactor and is heated to an elevated temperature before being introduced into the reactor. The flow and composition of the reducing gas are determined at a first location before the gas enters the reactor. The effluent gas from the reactor is cooled and its flow and composition determined at a second location after the gas has been cooled. The measured flows and compositions are correlated with the rate of sponge iron production to obtain a measurement of percentage reduction of the ore and this measurement is used, either manually or automatically, to regulate the rate of removal of sponge iron from the reactor to maintain the percentage reduction at a predetermined desired value.

Abstract: A method for inhibiting carburization of metal-bearing material in the reduction zone of a vertical shaft, moving bed reactor for the direct gaseous reduction of iron ore to sponge iron. Carburization within the reduction zone is decreased by regulating the water vapor content of the reducing gas in any of various ways, e.g., by adding water vapor in the form of steam to the reducing gas either before it enters the reduction zone, while it is within the reduction zone, or after it leaves the reduction zone or by recirculating a portion of the effluent gas from the reactor and cooling the recirculated gas to a predetermined extent.

Abstract: A method and apparatus for measuring the percentage reduction of iron ore in a reduction reactor of a multiple reactor gaseous reduction system. In accordance with a preferred embodiment, the flow and composition of the reducing gas fed to the reduction reactor and the flow and composition of the reactor effluent gas after cooling are measured and the measurements are fed to a computer along with data on the initial weight of the charge to the reactor, the moisture content of the charge and the initial reducible oxygen in the charge. The computer is programmed to compute the rate of oxygen removal from the charge, integrate the rate of removal with respect to time and compare the integral with the initial oxygen content of the charge to evaluate percentage reduction thereof.

Abstract: An improvement in a method for the batchwise gaseous reduction of iron ore to sponge iron in a multiple unit reactor system including a cooling reactor and at least one reduction reactor. Reduction is effected with a gas composed largely of carbon monoxide and hydrogen which may be, for example, generated by reforming a mixture of steam and natural gas or other gaseous hydrocarbons at an elevated temperature. The reducing gas requirement of the system is decreased by adding to the gas fed to one or more of the reduction reactors a minor amount of a hydrocarbon gas or vapor, e.g., natural gas, methane or a combination of methane and recycled spent reducing gas.

Abstract: A method and apparatus for measuring and controlling the percentage reduction of iron ore in a vertical shaft, moving bed, gaseous reduction reactor. Reducing gas comprising hydrogen, methane, carbon monoxide and carbon dioxide is fed from a source of such gas to the bottom of the reduction zone of the reactor and is heated to an elevated temperature before being introduced into the reactor. The flow and composition of the reducing gas are determined at a first location before the gas enters the reactor. The effluent gas from the reactor is cooled and its flow and composition determined at a second location after the gas has been cooled. The measured flows and compositions are correlated with the rate of sponge iron production to obtain a measurement of percentage reduction of the ore and this measurement is used, either manually or automatically, to regulate the rate of removal of sponge iron from the reactor to maintain the percentage reduction at a predetermined desired value.

Abstract: An improvement in a method for the batchwise gaseous reduction of iron ore to sponge iron in a multiple unit reactor system including a cooling reactor and a series of reduction reactors. Reduction is effected with a gas composed largely of carbon monoxide and hydrogen generated by reforming a mixture of steam and natural gas or other gaseous hydrocarbons at an elevated temperature. The reducing gas pressure drop through the system is decreased by using an out-of-line cooling reactor and cooling gas loop, thereby making it feasible to use three or more reduction reactors in series and thus enhance the efficiency of utilization of the reducing gas.Also the use of an out-of-line cooling reactor permits independent control of both the gas flow rate and gas composition in the cooling loop.

Abstract: A process for the direct gaseous reduction of iron ore to sponge iron wherein the sponge iron is cooled with a carbon-containing cooling gas by a dual temperature procedure that increases transfer of carbon from the cooling gas to the sponge iron and thereby permits the production of a product having a combination of relatively low or moderate metallization and relatively high potential metallization. Increased productivity of the direct reduction plant and of the overall integrated steel plant are achieved.