| 摘要 |
PURPOSE:To expand width of utilized hydrocarbon, to manufacture reduced gas at a low cost and easily, and to realize high temperature reduction, by placing in series a spare reducing furnace of a fluid layer system, a gas reforming furnace and a reducing furnace, and making iron ore grains and hydrocarbon flow through in order. CONSTITUTION:Iron ore grains are heated by a heater 1, and after that, are fed to a spare reducing furnace 2, and are brought into contact with hydrocarbon preheated to such an extent as it is not decomposed, by a preheater 5, and circulating gas containing oxidizing gas such as CO2, H2O, etc., which has passed through a heater 21 from a line 12. Subsequently, a part of the hydrocarbon is decomposed and becomes reduced gas, and a part by-produces C and sticks onto the surface of iron ore grains, and the iron ore grains are prereduced. The C stuck grains are fed to a gas reforming furnace 3 together with decomposed gas which has passed through a purifying device 18, and a part of reduced iron of a reducing furnace 4, and the decomposed gas is reformed to reduced gas mainly consisting of CO, H2, etc. This reduced gas is made to pass through a heater 22, also iron ore and the reduced iron which has been partially oxidized are fed to the furnace 4 from the furnace 3 and are made to contact with each other, and reduced iron is generated, and its waste gas is fed to the furnace 2. |
