1987 Volume 73 Issue 11 Pages 1519-1526
Iron are sinter was reduced in a graphite crucible with Ar70%-(CO + H2)30% gas mixtures and the effect of addition of H2 gas to Ar-CO gas mixtures on reduction was investigated during heating at constant rates. The process was followed by gas analysis. Apparent reduction rates with CO, H2 gases and C, and overall rate as the sum of those rates were separately calculated from the mass balances of oxygen and carbon.
The reduction rate increased with addition of H2 gas, especially at the temperatures below 1 100°C, and the smelting reduction above 1 280°C decreased. The overall rates of reduction with Ar-CO-H2 gas mixture were computed assuming the additivity for the reductions with CO and H2 gases. Then, it was found that there were negative deviation from additivity about 450-600°C and positive one in the range of 600-800°C. The extraneous effects were attributed to the direct reaction of iron oxide with CO gas and C promoted by H2 gas addition. It was also concluded that water-gas shift reaction played at least no important role in accelerating the reduction.
