Abstract
Heating-up and reaction characteristics of burdens in the oxygen blast furnace process were studied with an one-dimensional mathematical model to obtain the following results ; (1) With increasing oxygen concentration in blast, heat flow ratio augments, temperature goes down and reduction is retarded. Boyond the heat flow ratio of 0.90, the preheating gas injection is required. (2) Appropriate range of preheating gas volume and temperature in which the direct reduction rate is low and low fuel rate is realised is ; gas volume corresponding to heat flow ratio of 0.740.90, temperature 600200°C. (3) The composition of preheating gas has little influence. The level of preheating gas injection is adequate in upper shaft as long as the heat transfer capacity from the top of furnace is sufficient. (4) Solid temperature at tuyere level can be controlled with the theoretical flame temperature, and with preheating gas volume and temperature in the low fuel rate condition. (5) Operational fuel rate range is wide ; 500 kg/t (with preheating gas)1200kg/t (without preheating gas).
