The thin-layer microwave drying characteristics of Ximeng lignite was experimentally studied

under conditions with different coal sizes and microwave output powers. The results show that

with an increase in the coal particle size and microwave output power

the coal's drying rate increased and the drying time shortened.Under conditions with different microwave output powers and coal particle sizes

the coal's drying characteristic curve showed two stages: the fast drying period and falling rate drying period. Among the commonly used models

the Midilli-Kucuk model was the most suitable to describe the microwave drying characteristics of Ximeng lignite. The surface diffusion coefficient obtained by the Fick second law increased with the coal particle size and microwave output power

especially for coals with different size distributions.