Abstract
The weight loss curves of wustite-coal char composite pellet were measured and the rate is proved to be much faster than the overall rate of the indirect reactions of reduction and gasification. The indirect reaction rates were calculated by substituting the rate constant of reduction and the constant of iron catalyzing gasification estimated by the reduction of the wustite and the gasification of the char in electrolytic ironchar composite pellet into the rate equation of the grain model. The large difference in the experimental and calculated weight loss curves may be attributed to the direct reactions of wustite with char and carbon dissolved in reduced iron. The weight loss curves of the direct reaction were gravimetrically measured in vacuum. The experimental weight loss curves were still significantly faster than the sum of the weight loss curves of the calculated indirect reactions and the direct reactions in the later stage of the reactions of the composite pellet. It was reasonably concluded that the significant acceleration effect of the close mixing of wustite and char in the pellet can be attributed to the direct reduction of wustite with dissolved carbon in indirectly reduced iron.
