Abstract: A high proportion of the inorganic materials, (ash) content is removed from coal by providing the coal as a suspension with a liquid hydrocarbon oil, mixing an aqueous agglomerating liquid comprising water with the suspension, mixing a particulate material having a hydrophilic surface that is readily wetted by liquid water with the suspension, agitating the suspension to agglomerate the ash, and then separating the ash from the remainder. The particulate material having a hydrophilic surface may be ash, agglomerated silica flour, coarse silica chips, limestone or peat moss, and a binder for the ash may be dispersed or dissolved in the aqueous agglomerating liquid. In some instances the coal may be initially in the form of an aqueous suspension, and the coal can either be agglomerated from the suspendant by using a portion of the liquid hydrocarbon oil and then adding the remainder, or filtered therefrom and then the filter cake mixed with the liquid hydrocarbon oil.

Abstract: Ball agglomerated particulate material is produced by comminuting the material to produce coarse particles having a size predominantly within the range 0.3 mm to 1.4 mm, and fines, then feeding the coarse particles, fines and an agglomerating liquid into a rotating ball agglomerating mill with the volume fraction of the coarse particles being 20% to 80% by volume of the total solids feed to the mill, continuing rotation of the mill until agglomerated balls are produced having a continuous network of fines interspersed with the coarse particles such that: ##EQU1## WHERE .epsilon. = THE POROSITY OF THE AGGLOMERATES,.epsilon..sub.o = the porosity of similar agglomerates formed entirely of the fines, m is the above mentioned volume fraction of coarse particles, andK = 0.7 to 1.0,And removing the agglomerates thus formed from the ball agglomerating mill.