1992 年 32 巻 7 号 p. 838-847
A new oxygen blast furnace process, which is characterized by the injection of preheating gas into the shaft, was developed. For the development of the process, operation tests using an experimental blast furnace were carried out, and proved this process to be applicable as an ironmaking process. Mathematical model simulations were also carried out and the process characteristics were clarified on a commercial scale, in comparison with those of a conventional hot blast furnace process.
Through the analysis of the experimental blast furnace operation and the mathematical model simulations, this process was found to have the following characteristics;
(1) Heating-up and reduction of burden assured throughout the furnace by means of the preheating gas injection.
(2) Appropriate preheating gas, in which the low fuel rate is realized, is the range of preheating gas flow rates corresponding to thermal flow ratio in the upper part of 0.74-0.90 and the range of temperatures 600-1200°C.
(3) The preheating gas composition has little influence on the reduction in the lower part.
(4) The position of preheating gas injection is adequate in the upper shaft as long as the heat transfer is secured.
(5) Operational fuel rate range is wide; 500 kg/t (with preheating gas)-1200 kg/t (without preheating gas).
