THE ROLE OF PHYSICAL FACTORS IN MASS-TRANSPORT DURING SINTERING OF COAL ASHES AND DEPOSIT DEFORMATION NEAR THE TEMPERATURE OF GLASS TRANSFORMATION

The role of physical properties of melts such as viscosity, diffusion, and surface/interfacial tensions in sintering and deformation mechani sms of ash deposits above glass-transformation temperature is discusse d. The differential thermal analysis (DTA) technique was applied to me asure glass transformation and crystallization temperatures, Sintering of selected coal ashes was performed as a function of temperature in air. The mechanical properties of sintered ashes were measured below a nd above the glass-transformation temperature, T-g. It was found that sintering propensities of amorphous ashes and superplastic-like deform ation of deposits above T, depend on mass transport phenomena in the i ntergranular liquid phase. (C) 1998 Elsevier Science B.V. All rights r eserved.