RACEWAY SMELTING REDUCTION PROCESS WITH F INE IRON-ORE INJECTION FROMBLAST-FURNACE TUYERES

The knowledge on the microscopic reduction behavior of fine iron ore i n hot reducing gas flow is indispensable to accurate description of th e extremely complex raceway combustion zone induced by PCI(Pulverized Coal Injection) and OI(fine iron Ore Injection) from blast furnace tuy eres. In the studies using the vertical flow reactor and the tube type reactor where fine materials were transported by the pressure differe nce in the gas chambers, and thereby a short residence time and a rapi d heating rate of fine materials in the raceway combustion zone were s imulated, the reduction degree of fine iron ore as well as the reducti on morphology were investigated in detail under the conditions of the combined injection(PCI+OI) and the carbon coated ore injection. The ex perimental results revealed that the in-flight reduction degree of fin e iron ore was significantly increased mainly by the improved efficien cy of contact of fine ore particles with reducing agents. And the carb on coating of the fine ore surface achieved the most excellent conditi on for promoting the in-flight smelting reduction.