Changes in heat transfer when sintering porous goethitic iron ores

Heat transfer during iron ore sintering has not been given due consideratio n since the important concepts were developed. Convective heat transfer dur ing sintering is extremely important as it determines the name-front speed and, consequently, productivity and sinter quality. Concepts developed in c hemical engineering heat transfer are put forward as a means of understandi ng the factors that determine the flame-front speed. The definition of heat and name fronts, the roles of convection, conduction and radiation in heat transfer, the effect on convective heat transfer of air now velocity throu gh the bed, the importance of heat transfer from the name front and the eff ect of the thermal capacities of the solids and gases on convective heat tr ansfer are discussed. The properties of the available heat during melt form ation are also considered as being important in sintering. The influence of an increase in the proportion of porous ores, which are assimilated more r eadily than denser ores, is assessed by application of these concepts. The porous ores should be assimilated preferentially to form melt since the ene rgy required for their assimilation is less.