Effects of Particle Size Distribution of MgO and Carbon on MgO–C Reaction Behaviour

Abstract

The effect of the particle size distribution of MgO and carbon on the behaviour of the MgO–C reaction was investigated by heating four kinds of MgO–C sample bricks with different size distributions, and the reaction mechanism was discussed quantitatively using an improved MgO–C reaction model in which the unreacted core model was combined with a statistical distribution function. As a result, it was found that the MgO–C reaction is promoted when the ratio of fine particles of MgO increased and finer particles of carbon were used in the brick. A kinetic model of the MgO–C reaction based on the unreacted core model was developed and improved by combining the model with the statistical distribution function. The improved model considers the effect of the particle size distribution of the refractory materials on the MgO–C reaction rate. The effect of the carbon particle size on the MgO–C reaction can be explained using this model. The effect of the MgO particle size on the reaction behaviour can also be explained by the model under conditions with a relatively large ratio of MgO aggregates. However, when the ratio of fine MgO particles was large, the calculation result was much larger than the experimental result. As a reason for this, it is predicted that the fine particles sinter with each other during heating, resulting in an increase in the apparent particle diameter of the fine MgO.