A method of separating a mixture of liquid and insoluble solids in a filter press may comprise: diluting the mixture; adding a flocculating agent to the diluted mixture and stirring to form a chemically processed mixture; pumping the chemically processed mixture into a chamber between two filter plates in the filter press to form a filter cake, wherein the chamber is lined by filter cloths, and wherein, during the pumping, filtrate is forced through the filter cloths and out of the chamber; heating the filter cake in the chamber, wherein, during the heating, filtrate is forced through the filter cloths and out of the chamber; and releasing dried filter cake from the chamber. Furthermore, before the diluting, additional solids may be added to the mixture. The method may be used to dewater drilling mud, and mixtures of drilling mud with drill cuttings.