A process for producing a slurry of a pulverized carbonaceous material having a predetermined particle size distribution with a certain average particle size and a certain maximum particle size is described. The process, which includes a comminuting phase comprising at least two milling stages and combining the milled material with a carrier liquid to provide the slurry is characterized by the following steps:(a) that the carbonaceous material is milled in a first milling stage;(b) that the milled product from stage (a) is divided into coarse material having a particle size which at least is larger than the average particle size of the predetermined particle size distribution and into fine material having a particle size smaller than that of the coarse material;(c) that the coarse material from stage (b) is milled in at least one further milling stage to produce at least one further portion of fine material, the average particle size of which is smaller than the average particle size of the final slurry; and(d) that a slurry is produced of the combined portions of fine material from the different stages.