A smelting reduction reactor with post-combustion in a foamyslag has two slag layers. In the lower, iron oxide from the slag is reduced to ironby carbon. In the upper, the gas from the reduction is post-combusted toGO2+H2O. The post-combustion heat is transferred from the rising post-combustion gas to the upper slag, and, therefrom, by slag circulation to the lowerslag layer where the endothermic reduction reaction takes place. Unavoidably,slag circulation also transfers part of the char into the upper slag where it isoxidised. A kinetic post-combustion and heat transfer model describes thesephenomena. The main process parameters, namely real post-combustion degree,carbon oxidation, heat transfer efficiency, distribution of temperatures of gas andslag in the single regions of the reactor, coal consumption, and iron productionrate are given as functions of the ratio of post-combustion oxygen to gasevolution rate of the system. The main influences on which heat efficiency andoff-gas temperature as the most important output parameter depend are discussed.Controlled stirring and a regular gas through-put are of primary importance. Therequired values are given. A comparison with pilot plant results of the CSMprocess shows good agreement with the model results.
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