Process for the dehydration of fatty sludge and the recovery of chemicals

Claim 1

A process for concentrating a precipitated stabilized fatty sludge which has been recovered from a fatty, proteinaceous, aqueous emulsion waste effluent, said stabilized sludge being obtained by adding to the effluent an acid hydrolyzing metal salt in an amount sufficient to bind organic material present into a complex and reducing the pH to below 5, whereafter the formed complex is precipitated, in the presence of alkaline earth ions by raising the pH to 6-9, whereafter the thus formed stabilized sludge is separated, which process consists essentially of the steps of acidifying said stabilized sludge to a pH less than 2, to thereby form a first aqueous phase and a supernatant, concentrated fatty phase which is separated from said first aqueous phase, heating said separated, concentrated fatty phase to form thereby a free fatty acid-containing liquid phase and a second aqueous phase which contains the precipitation chemicals of said stabilized fatty sludge, and separating said free fatty acid-containing liquid phase from said second aqueous phase.