KINETIC STUDIES OF THERMAL DEHYDRATION OF GYPSUM AND APPLICATION OF REACTION DIAGRAM

Abstract

Drying and thermal dehydration of gypsum in the shape of thick circular plate and sphere ware investigated, especially by using a fluidized bed to reduce the film resistance for heat transfer.
Analyzing the change of temperature profile within the gypsum sample and applying the reaction diagram proposed in the previous paper which is based on the non-isothermal analysis of unreacted-core model, the authors could successfully clarify how the transport rates of diffusion and heat transfer affect the kinetic behavior of the process. The reaction path could be drawn with temperatureconcentration coordinates on the reaction diagram.
The reverse hydration reaction was also studied, and the reaction diagram is also verified to be very useful in this process.