| 摘要 |
<p>In a method of producing liquid pig iron (43) or liquid steel precursors from charges consisting of iron ore (5) and fluxes, having at least in part a proportion of fines, the iron ore is reduced directly to sponge iron in two or more reduction stages (1, 2) by the fluidised-bed method. The sponge iron is then melted in a smelting-gasification zone (39), with carbonaceous materials and oxygenous gas added; a reducing gas containing CO and H2 is generated, which is introduced into the reducing zones of the reduction stages (1, 2), reacts there, is drawn off as top gas, and supplied to a consumer, where appropriate. In order to achieve uniform reduction of the iron ore with optimum utilisation of the reducing gas, in a first reduction stage (1), the iron ore (5) is fractionated into two or more fractions of different grain-size distributions, with the help of the reducing gas; each fraction is reduced with the reducing gas in its own fluidised bed (6, 15); the reducing gas sustaining a first fluidised bed (6), containing the coarse-grain fraction, and separating the fine-grain fraction from it, and additional reducing gas being introduced directly into the other fluidised bed (15); reduced iron ore (5) is withdrawn from both the first and the additional fluidised beds (6, 15), and the fine-grain and coarse-grain fractions reduced in the first reduction stage (1) are reduced further in one or more additional reduction stages (2), that operate in the same way as the first reduction stage (1); from the last reduction stage (2), the fine-grain fraction is fed into the smelting-gasification zone (39) under agglomeration by addition of oxygen, and the coarse-grain fraction is gravity-fed directly into the smelting-gasification zone (39).</p> |
