Process for obtaining a product which can be used in cement works from purification sludges through treatment with calcium hypochlorite and calcium hydroxide

摘要

Process for obtaining a product which can be used in cement works which essentially comprises subjecting purification sludges with a substantially macromolecular organic component and a pH between 7 and 8.5 to the following operations: a) addition of 0.4 - 0.6 kg of calcium hypochlorite per litre of sludge at a temperature within the range 15-45 degree C until a pH between 9 and 9.4 is attained, b) addition of 60-100 g/l of calcium hydroxide to the sludge so obtained until a pH between 11 and 11.5 is attained, c) separation of the solid fraction from the supernatant, with dispatch of the latter to ordinary purification processes, and d) dispatch of the abovementioned solid fraction, following the possible addition of calcium oxide, to a cement works.