1992 Volume 78 Issue 7 Pages 1230-1237
A mathematical model of blast furnace raceway zone with pulverized coal (PC) and fine ore injection was developed to describe the reaction behaviors of injected PC and fine ore. The model is based on differential balances of mass and heat taking account of the reaction kinetics and heat transfer of PC, coke. fine ore and gases.
The kinetic parameters of thermal decomposition and reduction of fine ore were determined by the laboratory test. The kinetic parameters of PC and coke combustions were determined by applying the model to a experimental combustion furnace and to a actual blast furnace with all coke and PCI operations, respectively.
Furthermore, the raceway phenomena with simultaneous injection of PC and fine ore were predicted and the effects of operating conditions on reaction in a raceway were studied using the model. The results were summerized as follows.
1) The combustion of PC and reduction of fine ore are restrained by the temperature drop of gas occured by the complex injection of PC and fine ore.
2) The final combustion degree of PC in the raceway is slightly affected by injection rate of fine ore.
3) Increase of blast temperature can make higher reduction degree of ore than oxygen enrichment.
