Moisture transport during contact sorption drying of coal fines

Studies have shown that contact sorption drying is a feasible technique to dewater fine (+0.15mm–0.5mm) and ultra-fine (−0.15 mm) coal. The aim of this article is to further investigate the drying mechanism involved. It could be shown that moisture transfer occurred primarily in the liquid phase, requiring direct contact between the coal and sorbent particles to facilitate the movement of the water. Moisture transfer was enhanced by operating with a higher sorbent to coal mass ratio. When drying smaller coal particle size ranges, the resistance to liquid transport decreased, leading to better desorption results. These improvements were mainly as a result of a greater contact area between the sorbent and coal particles