A method and plant for burning sludge or filter cakes during the cement clinker manufacture where the cement is manufactured in known manner by the cement raw meal being preheated, calcined and burned into clinker with subsequent cooling of the clinker and where the sludge is dried and finely divided prior to burning. In connection with this method a drying method is indicated by means of which the drying gas volume through the drier unit is substantially reduced. This is done by feeding hot raw meal from either the preheater or a separating cyclone installed in connection with the calciner to the drier unit - which may be a drier crusher. In principle, there is no upper limit to the water content in the sludge which may be used for the process, and applicable types of sludge include for example sewage sludge, bleaching earth, paper sludge, fibre rejects, combustible chemical residues, e.g. waste derived from the manufacture of nylons and pesticides, drill sludge resulting from oil exploration and similar types.