method may be used with aqueous coal slurries such as those produced when coal is shipped by pipeline coal washery slimes when coal is separated from contaminants after mining suspensions produced in ore processing such as illmenite ore processing slurries or sludges or haematite ore processing slurries or sludges clay suspensions produced in production of ceramics fermentation and sewage sludges and protein hydrolysates fuel materials such as tar sands oil sands oil shale coal liquified products pitch and their slimes produced during processing organic liquid suspensions including as examples those where carbon is the solid suspended alcohol and organic dye suspensions oil clay suspensions oil filter cakes obtained in pressing operations the organic liquids may be alcohols ketones alkanes aromatic alicyclic aliphatic and heterocyclic compounds and the like the organic liquids may be nonpolar hydrocarbons or have polar groups it was noted that lower molecular weight organic compounds with low boiling points were not readily amenable to the procedure since the vacuum used caused them to evaporate during tests this problem can be remedied by reducing the vacuum lowering the temperature or using other augmentation means 16 such as centrifugation it is believed that the method of the invention is generally applicable to the above listed sludges and slurries separation may be further augmented by addition of small quantities of surface modifiers such as detergents or surfactants examples of these surface modifiers are polyacryl amide gels polystyrene sulfonates and the like the preferred amount is capable of being readily determined by those skilled in the art these surfactants are to be added prior to the concurrent application of the acoustical and electrical fields the types of surfactants could be nonionic anionic or cationic types the.