| 摘要 |
PURPOSE:To efficiently melt and reduce ore at a low-energy level by blowing ore and a flux along with high-temp. are into the lower part of a shaft furnace packed with a carbonaceous solid reducing agent from the upper stage, and blowing a flux and a carbonaceous reducing agent into the lower part from the lower stage. CONSTITUTION:A packed bed is formed only with a carbonaceous solid reducing agent from a coke feeder 5 in a smelting and reducing furnace 1, and the upper- and the lower-stage tuyeres 2 and 3 for blowing in high-temp. air are provided at the lower part of the furnace. Powdery ore contg. a metallic oxide and a flux is blown along with high-temp. air into the furnace from the upper-stage tuyere 2. Conse quently, the ore is melted, dripped, and reduced. A mixture of a powdery carbonaceous material and a flux is simultaneously blown along with high-temp. air into the furnace from the lower-stage tuyere 3. The combustion of the carbonaceous material-packed bed is controlled by the combustion of the blown-in carbonaceous material, and the dripping velocity of the ore is regulated. Furthermore, the composition of the slag dripping from the upper-stage tuyere 2 is controlled by the blown-in flux, and easy-to- discharge slag having low m.p. and low viscosity is formed. Difficult-to-reduce metallic oxide ore such as chromium ore is efficiently smelted and reduced in this way. |
