A mathematical model for silicon chlorination

A mathematical model was developed to complement an experimental investigation on the kinetics of chlorination of a fixed bed of −4 to +14 mesh silicon particles. By comparing the experimental data with the results obtained from the model a good agreement was found. The model evaluated the mass transfer coefficient (kg) and the rate constant (kr) as a function of temperature, bed porosity, and bed height. It was observed that the difference between kg and kr was higher for the lower temperature range characterizing the greater sensitivity of kr at more elevated temperatures. It was also evidenced that bed compacting exercised greater influence than bed height on mass transfer. Therefore, the effect of compacting on the behavior of the chlorination system was more significant due to the increased role of the diffusion component on the mechanism of mass transport.