Kinetic reaction models of chromite reduction by CO

A structural grain model is introduced for describing the chromite pellet reaction with a reducing gas CO. The pellet is composed of a large number of chromite grain particles, and the reduction rate of the chromite pellet is contributed by all these individual particles. The mathematical formulations have been built up, and the numerical solving method has been presented. On the other hand, in order to understand the details of the chromite reduction, the Kemi chromite phase compositions were estimated based on the literature study. The reduction tendency of the reducible species of the chromite was thermodynamically analyzed. Further, the mechanism of the multi-layers reaction model was examined. Seven interfaces reaction was proposed, and the relationships among different reduction rate on the interfaces were also framed. The reduction interface movement was expected to be calculated by mathematically solving the equations of the model. (orig.)