| 摘要 |
<p>PURPOSE:To improve the recovery efficiency at the time of recovering zinc in iron-making dust by fluidized layer reduction. CONSTITUTION:In the case of recovering the zinc in the iron-making dust by a vertical type fluidized layer reduction furnace and a circulating fluidized layer arranged with the fluid circulating system at the outside thereof, by adjusting the reducing degree of reducing gas to be introduced into the fluidized layer reduction furnace. Shown with the ratio (CO+H2)/(CO2+H2O) at 0.25-3, the reducing ratio of Fe content is restrained to <=40%. Further, the adjustment of the reducing degree of reducing gas is executed by recycling the exhaust gas after reduction and mixing with the reducing gas. By this method, the reducing energy is made in the low level. A large part of the Fe content is reduced to FeO and metallic Fe is not produced on the grain surface in the large quantity to hardly occure and to improve operatability. The cost of the raw material gas is reduced because of the recycle of the exhaust gas.</p> |
