Reaction engineering parameters for carbothermal production of β'-sialon form kaolin

It is shown that the grain model can be used to describe the engineering parameters of the carbothermal conversion of kaolin-coal mixtures into ß' -sialon. Below a critical pellet diameter, 1 mm at 1400°C, pore diffusion can be neglected and the overal reaction rate is determined by the chemical reaction. For partial CO pressures below 0.05 bar at 1400°C simple design calculation can be used . Under these conditions the formation of ß' -sialon can be treated as an elementary reaction. At higher partial CO pressures at least two reaction steps are involved.