1993 Volume 79 Issue 10 Pages 1151-1156
The knowledge on the microscopic reduction behavior of fine iron are in hot reducing gas flow is indispensable to accurate description of the extremely complex raceway combustion zone induced by PCI(Pulverized Coal Injection) and OI(fine iron Ore Injection) from blast furnace tuyeres. In the studies using the vertical flow reactor and the tube type reactor where fine materials were transported by the pressure difference in the gas chambers, and thereby a short residence time and a rapid heating rate of fine materials in the raceway combustion zone were simulated, the reduction degree of fine iron are as well as the reduction morphology were investigated in detail under the conditions of the combined injection(PCI+OI) and the carbon coated are injection. The experimental results revealed that the in-flight reduction degree of fine iron are was significantly increased mainly by the improved efficiency of contact of fine ore particles with reducing agents. And the carbon coating of the fine are surface achieved the most excellent condition for promoting the in-flight smelting reduction.