Abstract: The process of the Mechanical/thermal dewatering of Victorian brown coal was explored at 150 ℃ and stepped pressure of 3-6-12-24 MPa. The moisture content of the product was 0.31 g/g dry coal and the reduction of the moisture was 66.3 %. During every pressure stage, the process could be divided to two stages: primary consolidation and second consolidation. In the process of primary consolidation, the interparticle and intraparticle moisture of brown coal was removed with high dewatering rate, which was the main stage of dewatering. In the process of secondary consolidation, creep deformation of lignite skeleton happened and caused additional volume reduction, but the dewatering rate was lower than the primary consolidation. With the pressure increasing, macropores and mesopores were destroyed gradually and it was harder to dewater. The rate of dewatering in both of the primary consolidation and second consolidation stages decreased with pressure increasing, but until 24 MPa, the moisture content was reducing, which means more moisture could be remove at 150 ℃.

Key words: lignite, Mechanical/thermal, dewatering process, consolidation.