A method for the manufacture of polyether ketone ketone (PEKK), including the steps of: reacting 1,4-bis(4-phenoxybenzoylbenzene) and/or diphenylether with at least one difunctional aromatic acyl chloride, in a reaction solvent and in presence of a Lewis acid, to obtain a product mixture including a PEKK-Lewis acid complex; contacting the obtained product mixture with a protic solvent, so as to form a dispersion that includes a liquid phase including Lewis acid and a second phase, e.g., a solid phase, including PEKK; and separating the second phase from the liquid phase by centrifugal filtration, so as to recover a crude PEKK and a effluent containing Lewis acid, wherein step (iii) includes a step of centrifugal filtration.