摘要:
A shaft furnace for reducing ores with a gas, wherein the furnace is constructed to destroy the plug-flow state of ores in or above a plug-flow zone where a reduction ratio of the ores is 50 to 70%, in order to prevent the clustering by changing the plug-flow zone into a shear-flow zone. Further, the shaft furnace for reducing ores with a gas is so constructed that a hydraulic radius R (cm) of the furnace in the reduction zone in which the reduction ratio is greater than 50% is selected to be,R.ltoreq.120 exp(8.6-0.009T)wherein T denotes the temperature (.degree.C.) of the reducing gas, in order to prevent the clustering.
摘要:
The present invention discloses a direct reduction process for producing reduced iron by reducing iron ores and/or pellets with reducing gases, wherein the iron ores and/or pellets are reduced to a degree of reduction of 30-80% by a reducing gas containing 15-40% by volume of methane at a temperature of more than 950.degree. C. and further reduced by a reducing gas containing high proportion of carbon monoxide and/or hydrogen at a temperature of below 1000.degree. C.
摘要:
The invention provides a novel process for concurrently carrying out production of reduced iron and thermal cracking of heavy oils in which the reaction of thermal cracking is performed in a fluidized state with the fine iron ore as the fluidized medium and the particles of the iron ore become coated with deposits of the carbonaceous by-product material. The fine iron ore with the carbon deposited thereon is introduced in a fluidized-bed reducing furnace and there reduced into reduced iron by contacting with a reducing gas which is produced in a gas reformer from the cracked gas or the residual oil separated from the products of the thermal cracking. In an improvement of the above process, the gas reformer is operated as a fluidized-bed reactor with the reduced iron as the fluidized medium and acting as the reforming catalyst. The reduced iron partially re-oxidized in the reforming reaction is again reduced to completely reduced iron either by recycling into the fluidized-bed reducing furnace or by introducing into a second fluidized-bed reducing furnace.
摘要:
A method of producing iron from finely divided iron oxide comprising the steps of: mixing iron oxide or iron ore fines with finely divided coal and a binder to form a mixture, agglomerating the mixture by compacting, pelletizing, or briquetting the mixture to form agglomerates or pellets, introducing the pellets to a rotary hearth furnace to prereduce the iron in the pellets, introducing the prereduced pellets into a smelting reduction vessel as the metallic charge constituent, introducing particulate carbonaceous fuel and oxygen to the smelting reduction vessel through the bottom of the vessel to react with the melt or bath within the vessel, reduce the iron to elemental iron and form an off gas containing CO and H.sub.2 introducing the off-gas into the rotary hearth furnace as process gas to prereduce the pellets therein, and drawing off the hot metal from the smelting reduction vessel.The prereduced compacts are preferably discharged from the rotary hearth furnace at a temperature of at least 1000.degree. C. into the smelting reduction vessel to form the molten iron product.
摘要:
A process for the direct reduction of iron oxide by blowing into a reduction furnace a reducing gas which is prepared by reforming a mixture of a reduction furnace exhaust gas and a gas mainly composed of methane, which comprises the steps of dividing the gas mainly composed of methane into two branch streams, mixing the first branch stream gas with a part of the reduction furnace exhaust gas and supplying the resulting mixture to the externally heated reformer furnace, to produce a high-temperature reformed gas; mixing the second branch stream gas with said high-temperature reformed gas and during the course to the reduction furnace, subjecting the mixture to endothermic reforming reactions in an after-reactor without external heating, utilizing the sensible heat of the high-temperature mixed gas, controlling the self-reforming reactions so as to lower the temperature and simultaneously adjust the composition of the high-temperature mixed gas, and blowing the reducing gas obtained into the reduction furnace. Effective use of the sensible heat can be achieved.
摘要:
Iron-ore oxidized pellets are produced from magnetite concentrate by the addition to the magnetite concentrate of at least one calcium compound selected from the group consisting of slaked lime, quicklime and limestone, to a basicity of 1 to 5, granulating the mixture thus prepared, drying the same, preheating the same at a temperature of from 1000.degree. to 1150.degree.C for 3 to 10 minutes, and thereafter firing the same.