1988 Volume 74 Issue 4 Pages 672-679
Smelting reduction rate of Cr-ore in top-and-bottom blowing converter was quantitatively estimated by 600 kg scale fundamental experiment and 100 t scale industrial furnace (LD-OB). The change of Cr oxide in slag with time showed zero-order reaction kinetics and the following points were clarified on the reduction rate.
1) The rate was in propotion to ε0.5 and L1.0, where ε was stirring energy, L was diameter of furnace.
2) The activation energy was about 210 kJ/mol.
3) The rate were not cleary affected by the kind of Cr-sources, namely, pellets, briquettes of powder ore, carbon containing briquettes and lump ore.
4) The rate increased with the increase in amount of carbon for reduction and the decrease of [%Cr].
According to these results, it was posturated that the transfer of Cr oxide in molten slag phase to the carbon-slag and the metal-slag interfaces was the rate controlling step. The reduction rate was formulated as a function of ε., L, [%Cr], temperature and the containing ratio of carbon for reduction in slag. The results of calculation showed fairly good agreement with the observed values.
