Effect of Atmospheric Gas Composition on Reaction Behavior of Low Porosity Carbon Composite Iron Ore Pellet

Abstract

The reaction behavior of low porosity carbon composite pellet produced by hot briquetting process was examined under various gas atmospheres such as N₂, CO and 50vol%CO-50vol%CO₂. The reduction reaction was affected largely by atmospheric gas at low temperature, and affected small at high temperature. On the other hand the gasification of coal was affected by not atmospheric gas but temperature. The effect of atmospheric gas on the reaction behavior was explained by variation of pressure in sample during reaction. The reactions in nitrogen gas atmosphere above 1000°C were controlled by the gasification of coal. Therefore, kinetic analysis in nitrogen gas atmosphere was carried out by using the first order reaction model. The temperature dependencies of reaction rate constants for the gasification of coal obtained by kinetic analysis were as follows.
k_CC=exp(5.51-130×10³/RT)
k_C2=exp(5.67-160×10³/RT)