Patent ID: 7820058

Claim:
A process for dewatering a slurry of hydrophobic coal particulate material comprising: i) forming a layer of hydrophobes on the surface of said hydrophobic coal particulate material and initially increasing the hydrophobicity of said hydrophobic coal particulate material by adding hydrocarbon oil to said slurry, wherein the hydrophobicity of said coal particulate material is increased; ii) adding a nonionic surfactant of hydrophile-lipophile balance (HLB) number less than 15 dissolved in at least one organic solvent; iii) allowing said nonionic surfactant to adsorb on less hydrophobic parts of the surface of said hydrophobic coal particulate material to further increase hydrophobicity of said hydrophobic coal particulate material having increased hydrophobicity from the addition of said hydrocarbon oil; and iv) effecting separation of water from said slurry of hydrophobic coal particulate material by subjecting said slurry to a mechanical method of dewatering.