SynopsisIn order to collect basic data on the smelting reduction process which consists of blowing powder iron ore and powder coal into molten iron bath with oxygen gas for a partial combustion, the reduction rates of molten iron oxide by the solid carbon or the carbon in molten iron were measured. Molten iron oxide in a steel or an alumina crucible was reduced by a rotating carbon rod. The carbon in molten iron in an alumina crucible was reacted with molten iron oxide which was melted in a steel container beforehand. The reduction rates were calculated from the amount of CO gas evolved. The following results were obtained:(1) The reduction rates o f molten iron oxide by the solid carbon were 0.21 0.82 X 10-~ mol-FeO/cm2s s at 1420 -' 1620°C, and the activation energy of the reaction were 75 and 31 kcal/mol for a steel and an alumina crucibles, respectively.(2) The reduction rates of molten iron oxide by the carbon in molten iron were 1.1-3.3X 10_4 mol-FeO/cm2.s at 142O-'1 620°C, and the activation energy of the reaction was 44 kcal/mol.(3) It was concluded that the reaction rate between the solid iron oxide and the carbon in molten iron was the highest among reactions between the solid or the molten iron oxide and the solid carbon, the carbon in molten iron, CO, or H2 gas based on the results so f ar.

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The effective thermal conductivities of unidirectionally aligned SiC whisker reinforced aluminum alloy matrix composites with different whisker diameters and volume fractions were measured from room temperature to 700 K. The thermal conductivity values parallel to the whiskers were found to be significantly higher than those in the normal direction. The thermal conductivities decrease as the whiskers' volume fraction is increased or their diameter is decreased. Effective-medium theory was used to calculate the effective thermal conductivity of the composites with consideration of the interfacial thermal resistance. The calculated values are in good agreement with the experimental ones.

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