Kinetics of Iron Ore Reduction by Coal and Charcoal

Abstract

In the present investigation, an attempt has been done to study the simultaneous effects of the major processing variables on the extent of reduction of iron ore pellets surrounded by coal or charcoal fines in an externally heated cylindrical steel container (diameter 5cm and height 10cm) placed in muffle furnace. The project goal is to compare the reduction potential of coal and charcoal in reduction of iron ore pellets. Wood charcoal contains very low levels of gangue, sulphur and volatile matter therefore, presenting itself as a very desirable reductant for the reduction of iron ore. The variables studied are time and temperature. The reduction was done at temperatures 8500C, 9000C, 9500C and 10000c. The percentage (degree) of reduction of pellets was calculated at 15, 30, 45, 60 and 90 minutes, after the furnace reached the predetermined reduction temperature. The experiments were statistically designed such that the effect of each variable can be quantitatively assessed and compared. The results showed that, there is an increase in degree of reduction with increase in time and temperature and use of charcoal instead of coal also increased the degree of reduction due to higher fixed carbon content of charcoal. The percentage of swelling showed a random variation with time and temperature. The activation energy for the reduction of iron ore pellet was found to be higher in case of coal as compared to that of in case of charcoal; this indicates that reduction of iron ore by charcoal will be more favorable in case of charcoal.