portion of the organic phase (L) leaving the extraction stage (5) and led away for working up by distillation (8.1), (8.2), in order to remove traces of acid, the water (Y) obtained here is returned to the aqueous phase at a suitable place, the resulting concentrated aqueous phase is combined with the optionally remaining resi› dues of (K) and (Q) and returned for reuse as stream (C). 

7. The process of claim 2, wherein aniline is used as auxiliary amine. 

8. The process of claim 2, wherein the polyamine mixture used is a polyamine mixture of the diphenylmethane series 

obtained during the acid-catalyzed aniline/formaldehyde condensation. 

9. In a process for the preparation of a polyisocyanate by phosgenating an aromatic polyamine, the improvement wherein the aromatic polyamine is prepared by the process of claim 1. 

10. In a process for preparing a cycloaliphatic polyamine by hydrogenating an aromatic polyamine, the improvement wherein the aromatic polyamine is prepared by the process of claim 1. 

* * * * * 

