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.
MORI KENJI
NARITA KIICHI
KANEKO DENTAROU
KAMIMURA NOBUO
MIYAZAKI KAZUHIRO