Recovery of caprolactam from oligomers and/or polymers of caprolactam

A process for recovering caprolactam from oligomers or polymers of caprolactam by cleavage of oligomers or polymers of caprolactam and subsequent working up by distillation of the caprolactam obtained in the cleavage, which comprises

• (a) cleaving oligomers or polymers of caprolactam to obtain an aqueous reaction mixture which contains caprolactam,
• (b) removing water from the reaction mixture obtained under (a) to obtain a residue,
• (c) distilling the residue obtained under (b) in an acidic medium and
• (d) then distilling distillate obtained in (c) in an alkaline medium to obtain caprolactam, or
• (c') distilling the residue obtained under (b) in an alkaline medium and
• (d') then distilling distillate obtained in (c') in an acidic medium to obtain caprolactam;
• wherein forerunnings are taken off in the distillation in the acidic or alkaline medium and are separated by distillation into a low-boiling fraction, which is fed to an incineration plant, and a bottom fraction, which is recycled to the distillation (c) or (d') in acidic medium;
• and wherein residue obtained in the distillation in the alkaline medium is separated by distillation and distillate obtained here in (c') being recycled to the distillation (d') in the acidic medium.