The importance of reducing the moisture content of fine coal, the nature of the retained water, and the means of its removal are discussed. A statistical technique, using a balanced block design, was used to isolate the significant factors determining water content of a coal filter cake. The most significant factor was particle size distribution. A simplex evolutionary operation (evop) was used to determine the optimal quantities of additives required to produce the lowest moisture content for a selected coal size. For this optimum condition (186 Ib H20 per lOO Ib dry coal), additions of 0045 Ib magnesium ion, 00026 lb Separan AP30, and 0098 Ib Aerosol OT, per lOO Ib dry coal were required. The work illustrated the uses of a statistical evop technique for the determination of optimal conditions in industrial research projects.