Abstract: The porosity and surface characteristics are in essence the mechanical concern of slurryability of the coal have been put forword in this paper, which based on the existing analysis of the influence factors. This conclusion has been verified by experiments with MengDong coal as the research object, the experiment results show that the slurryability of the coal which has been put in 105℃ dry atmosphere for 3 hours will become bad. The main reason is that the specific pore volume and the specific surface area of the coal has been improved during the drying process; In contrast the contact angle has been greaten, that means only using the measurement data of the contact angle to conclude the slurryability of the coal is not rigorous.

Key words: coal water slurry, coal quality, slurryability, mechanical concern