| 摘要 |
PURPOSE:To effectively steadily carry out the preliminary reduction of ore, by using shaft type evolved gas as reduction gas in countercurrently moving the ore and reduction gas in plural cyclones arranged in series by multi-steps. CONSTITUTION:Powdery granular ore is charged into the top stream cyclone 23 of preliminary reduction unit 2 from a raw material hopper 1 and at that time the reducing gas evolved from a cyclone 22 on down stream side is used as carrier gas. Further, the high temperature reducing gas evolved from a fusion reduction furnace 3 is utilized for the cyclone 21 positioned on the downest stream side. The reducing gas successively moves to 22 and 23 cyclones on upper stream side, flows into their insides respectively taking unreduced ore powder therewith, repeats the heating, reduction and separation and transfers the preliminary reduction product having reached required reducibility to the tuyere part of fusion reduction furance 3 via a discharge pipe 6. Thus, stable operation, high gas utilization ratio and the improvement of reducibility can be achieved. |
