| 摘要 |
PURPOSE:To refine directly powdery iron ore to a molten steel by using said ore as a raw material and passing successively the ore through a dry distillation furnace, rotary kiln and melting furnace. CONSTITUTION:A raw material mixture (a) composed of powdery iron ore having <=4mm. grain size, 15-22% pulverized coal and about 10% powdery lime is charged into a vertical-type dry distillation furance A from the raw materialcharging part 2 thereof. The material (a) falls in a raw material passage 8 constituted of partition walls 5 in the furnace A and when the high temp. waste gas from the succeeding rotary kiln B ascends in passages 7, the raw material is granulated by the viscous sticking effect of the heated pulverized coal and is preheated to 450-500 deg.C. The granulated raw material (b) enters the inside of the inclined rotary kiln B through a discharge port 17 and as the kiln rotates, the raw material moves diagonally downward. The granular raw material is reduced by the reducing flame from a combustion port 28 and flows in the form of the semi-molten iron and slag into the succeeding melting furnace C where the iron and slag are melted by the high temp. combustion gas from a fuel port 30 and a hot wind port 29. The molten material is oxidation-refined, if necessary, and is separated to the molten steel and the molten slag wich are taken out respectively through a tapping hole 32 and a slag discharging port 33. |
