Abstract: A method for capturing CO2 produced by cement plants by using the calcium cycle method comprising the integration of the process known as calcium cycle to the cement plant by using the cement plant raw materials and sub products in the calcium cycle plant and by using the calcium cycle plant raw materials, sub products and residual energy in the cement plant.

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: 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.

Abstract: 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.

Abstract: The present invention relates to a process for the production of metallic iron through direct reduction of iron ores and particularly to an optimized process which permits operation at higher reducing temperatures with minimized problems of sinterization and agglomeration of iron ore particles. It is also an object of the present invention to provide a process wherein the required size of the reducing gas generating unit is reduced. Both objects are preferably achieved by means of injecting only natural gas, or a similar methane-containing gas into the cooling loop of the direct reduction process and venting a portion of the cooling gas from the cooling zone to the reducing zone (preferably, on the order of 1% to 2% of the methane content of the cooling gas in relation to the volume flow of the reducing gas).

Abstract: 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.

Abstract: Apparatus for breaking apart agglomerations of particulate matter flowing in a vessel (particularly useful ina pressurized moving-bed vertical-shaft reduction reactor for the production of sponge iron) is exemplified by an externally mounted hydraulic cylinder having access to the interior of said vessel through a probe port, the piston of said hydraulic cylinder being provided with a conical probe positioned so as to be normally retracted out from the interior of said vessel but extendable by said hydraulic cylinder into and across the interior of said vessel, preferably at the narrowed discharge portion thereof, whereby said probe is angled to extend downwardly in the direction of flow of said particulate matter as well as across said flow to engage and break up any agglomerations of particulate matter in its path.

Abstract: A method for the gaseous reduction of iron ore to sponge iron in a vertical moving bed reactor having a reduction zone in the upper portion thereof and a cooling zone in the lower portion thereof which comprises using a coolant gas containing up to about 30% by volume of hydrocarbon, e.g., coke oven gas, and passing a mixture of the hydrocarbon-containing gas and steam through the cooling zone to cause the sponge iron therein to catalyze the conversion of the hydrocarbon/steam mixture to carbon monoxide and hydrogen.

Abstract: A method of using coke oven gas, and more generally gaseous mixtures containing up to about 30% by volume of methane, for the direct gaseous reduction of iron ore in a vertical shaft, moving bed reactor. In addition to the usual reduction zone and cooling zone, the reactor is provided with an intermediate reforming zone. A hot mixture of coke oven gas and steam is fed to the intermediate zone and reduced ore therein catalyzes the conversion of the methane of the coke oven gas to carbon monoxide and hydrogen. The reformed gas flows upwardly into the reduction zone of the reactor.

Abstract: A method for the gaseous reduction of particulate ores to metals in a moving bed, vertical shaft reactor using a reducing gas externally supplied from a solid or liquid fossil fuel gasification unit. The reducing gas is reformed in a reforming zone located within the reactor and treated prior to injection into the reduction zone of the reactor. A portion of the reducing gas produced in a coal gasification unit may be used to cool the metal in the cooling zone of the reactor.

Abstract: Sponge iron is carburized in the cooling zone of a vertical shaft iron ore reduction reactor by causing a carbon-containing gas to circulate in a closed loop including the cooling zone of the reactor and an external conduit containing a quench cooler and a pump. Improved control of the carburization of the sponge iron is achieved by measuring the specific gravity of the circulating gas and using the measured specific gravity value as a control variable effectively to regulate the flow of make-up carbon-containing gas to the cooling loop.

Abstract: A method and apparatus are disclosed for achieving improved reduction efficiency and thermal economy in the reduction of particulate metal ores, e.g., iron ore, in a vertical shaft, moving bed reactor. The reactor consists of a primary reduction zone, a cooling zone and a secondary reduction zone located between the primary reduction zone and the cooling zone wherein ferric carbide formed in the primary reduction zone further reduces the residual iron oxide in the presence of an inert gas at a temperature below the melting point of the sponge iron. In one embodiment of the invention the gas produced by the reaction in the secondary reduction zone is withdrawn into a combustion chamber where it is mixed with air and burned, carbon dioxide is removed from the effluent gas of the combustion chamber and the remaining inert gas is recirculated to the secondary reduction zone.

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.