A huge amount of pig iron is made as the crude materials of high quality steel and a few hundred million ton of coal is used in the world every year. Although coal is mainly used as coke, extensive replacement of coke by injected pulverized coal is a major challenge for blast furnace operation to decrease the cost and reduce coke demand. According to theoretical investigations and actual industrial operation, it seems clear that coal combustion is hardly achieved in the raceway at high injection rate. Consequently unburned fine materials are blown with the gas into the bosh and dead man areas with possible detrimental effects on gas flow and permeability of the coke column. The capacity of the furnace to consume these particles by solution loss is probably one of the limitations to coal injection. It is therefore important to understand the physicochemical and aerodynamic behavior of fines including the change of in-furnace phenomena.