5,648,519  25  26  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.  * * * * * 