| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable the use of inexpensive powdery iron raw material, not to need the use of electric power, natural gas, etc., and to reduce coal and oxygen consumption unit by subjecting internally charged carbon pellets to prereduction to half-reduced pellets by using the high-temp. combustible gas from a smelting reduction furnace. SOLUTION: The half-reduced pellets 22 are charged from a gas discharge port 5 into the smelting reduction furnace 1 and coal and a slag forming agent are supplied therein from a raw material feeding port 4. At this time, reduction is effected by blowing hot air from lower and upper tuyeres 11, 12 to form molten iron 6 on furnace bottom refractories 2. The molten iron is taken out of a tap hole 8. The half-reduced pellets 22 are obtd. by subjecting the internally charged carbon pellets 21 to a prereduction on an endless track like moving bed 20 of a prereduction furnace 17 disposed in the middle of an exhaust gas duct 13 connecting a gas discharge port 5, a dust collector 26, a blower 27, etc. The high-temp. combustible gas from the smelting reduction furnace 1 from a gas introducing port 18 and the preheated air from a heat exchanger 2 is supplied from an air tuyere 19. The internally charged carbon pellets 21 are obtd. by forming the iron raw material, coal and binder with a mixer 15 and a pelletizer 16.</p> |
