Coal slimes are mainly composed of coal and clay particles.The interaction energies among these particles were calculated using extended DLVO(DERJAGUIN-LANDAU-VERWEY-OVERBEEK)theory and the aggregation mechanisms were analyzed based on the settling experiments for coal-kaolinite and coal-montmorillonite suspensions,respectively,under different conditions of water hardness.The results indicate that for coal-kaolinite suspensions,as the water hardness reaches 10.0mol/L,the coal particles aggregate with each other easily,and then,the coal particles may aggregate with kaolinite particles.However,no aggregation occurs between kaolinite particles.A clay platelet network is formed in coal-montmorillonite suspensions by montmorillonite particles and coal particles are captured into the network.Coal and montmorillonite particles settle completely.
