Patent ID: 6837916
Filing Date: 2005-01-04
Classification: C21B,C21C,Y02P

Abstract:
1. A smelting reduction method comprising: (a) charging a carbonaceous material and an ore containing iron into a reacting furnace to directly contact the carbonaceous material and the ore; (b) reducing the ore until at least a part of the ore is metallized, the resultant reduced ore containing at least a part of the metallized metal being produced, and devolatilizing the carbonaceous material until a devolatilized carbonaceous material having a volatile content of the carbonaceous material is less than 10% is obtained under the condition that the carbonaceous material and the ore are in direct contact with each other; the step (b) of reducing the ore and devolatilizing the carbonaceous material comprising reducing the ore and devolatilizing the carbonaceous material at a temperature of at least 950° C. in the reacting furnace; (c) charging the devolatilized carbonaceous material and the ore containing at least a part of the metallized metal from step (b) into a smelting reduction furnace having a metal bath; (d) blowing a gas containing 20% or more of oxygen into the metal bath in the smelting reduction furnace to produce molten iron; and (e) controlling a heat load of the furnace wall by using a relationship among a de-volatilizing degree of the carbonaceous material, a post combustion rate in the smelting reduction furnace and the heat load of the furnace wall, the post combustion rate being a gas oxidation degree measured at the throat of the smelting reduction furnace, the gas oxidation degree being defined as follows: gas oxidation degree in %={(CO