1981 Volume 67 Issue 3 Pages 508-517
Experimental production of reduced pellets was performed using a small scale shaft furnace having inside diameter of 250 mm and reduction zone height of 2.7 m. The furnace was designed to permit continuous production of reduced pellets at the rate of 1.5 ton/day.
Effects of operational factors such as reduction temperature, gas composition and gas flow rate on the reduction behaviors of iron oxide pellets as well as the properties of products were investigated and following results were obtained.
1) Reduction rate of the pellets in the furnace increases according to the rise of reducing gas temperature and gas ratio.
2) The utilization of reducing gas is in a range from 30 to 43% and it becomes higher as reducing gas temperature increases.
3) The degree of reduction of products decreases rapidly when R value of reducing gas is less than 15.
4) The temperature in the furnace is lowered and progress of reduction is retarded as the ratio of H2 to CO in the reducing gas increases due to the endothermic reaction caused by H2 reduction of iron oxide.