15  5,648,520  16  The proportion of  these components  remaining in the first  polyamine fraction  (G) cannot, however,  be minimized in  The degree of protonation  of  (Q)  is generally >50%,  preferably 60%, and  may be up to 100%  when pure hydro› phobic solvent is  used as (P).  During the extraction  procedure which takes  place in the  extraction stage  (6)  auxiliary amine  and optionally  polyamine which  is still present are  removed from the  aqueous phase such  that the resulting  aqueous phase  (Q)  exhibits at all times  a higher degree of  protonation than the  aqueous phase  (K)  from the extraction  stage  (5).  In particular in the  second polyamine  fraction  (0)  the  relative enrichment  of the  components preferably  contained  in this fraction can  be varied and maximized  in targeted  manner.  The water (X) removed  in  (9)  may be used  simultaneously  to operate the washing  stages  (7.0)  and/or  (8.0).  The water  volume (X) may  also be removed  predominantly  or exclu› sively to operate the  washing stages  (7.0)  and/or  (8.0).  This  first variant on the  process according  to the invention affords  the opportunity for  considerable separation  efficiencies  in  the  fractionation  of polyamine mixtures  and enables numer› ous separation problems  to be resolved in a  satisfactory way.  The auxiliary amine  content in  (M)  is generally <30%,  preferably <20%;  a  hydrophobic solvent  liberated from  auxiliary amine is  optionally obtained  in  (8.1)  as a distillate.  At least part of the  distillate  (M)  is utilized, optionally  also  after the addition of  a part volume of (E)  from the distillation  stage  (7.1),  in the extraction stage  (6)  as the organic phase  (P)  for the  counter-current extraction  of at least a part  volume of the aqueous  phase  (K)  resulting in the extraction  stage  (5),  at least part of which  is supplied to the  extraction  stage  (6)  directly and/or indirectly  by way of an interposed  distillation stage  (9).  It  is irrelevant to carrying  out the process according  to the  invention whether  the removal of water  in  (9)  takes place  before or after passing  through the extraction  stage  (6).  With the aid of  a water  distillation stage  (9)  water is  removed from the  aqueous phase which  contains the acid,  or  from a partial stream  of the aqueous phase,  preferably after  leaving the extraction  stage  (5)  and before recycling  at the  beginning of the process,  and is added again,  in total  (Y)  or  in part quantities,  at one or more points,  at the latest before  the aqueous phase  enters the extraction  stage  (5).  The working-up stage  (8)  generally comprises  an at least  two-stage multi-stage  distillation  (8.1), (8.2)  in stage  (8.1)  whereof there is obtained  as the distillate  (M)  a  hydrophobic  solvent which is liberated  from polyamine and  is markedly  impoverished  as to auxiliary amine,  compared with the  intake product (L)  or (L’).  Fundamentally,  the aqueous phase  (H)  resulting in pro› cess stage (  4)  may be supplied  directly to the extraction  stage  (5).  However, because  the upper molarity  range of the  extraction stage  (  4),  a range which is far  preferred for certain  separation tasks, exceeds  the preferred molarity  range of the  extraction stage  (5),  it is a preferred  embodiment  of the  process according  to the invention to  decouple the molarities  in the different extraction  stages by optionally  removing  water by distillation  from the closed circuit  of the aqueous  phase, at a suitable  point, and adding  it again at a different  suitable point  In the distillation  stage  (8.1), (8.2)  there takes place  the  separation by distillation  of the distillation  residue  (0)  which is collected  in the process product  tank  (11)  as the  second part product.  The organic phase  (L)  or (L’) resulting in  (5)  is supplied  to the distillation  stages  (8.1)  and  (8.2),  optionally after  passing through the  washing stage  (8.0)  and/or optionally  after removal of traces  of acid with dilute  sodium hydroxide.  A further important  parameter of the  returned and  recycled aqueous  phase (C) is molarity.  According to the  invention, the molarity  of (C) may be varied  over a broad  range in dependence  on the respective  separation task.  Suitable points for  amine supply are  the aqueous phase  immediately before  entering the extraction  stage  (5)  with use  of auxiliary amine,  or at a point positioned  upstream,  preferably before  the aqueous phase  enters the extraction  stage  (3),  for example by direct  addition or by way  of an  extraction stage  (2)  positioned upstream.  The ratio by weight  of auxiliary amine  to solvent in  (J)  is  generally between  0.5:1 and3:1, preferably  between 1:1 and  2: 1. The ratio by weight  of extraction agent  (J)  to aqueous  phase is generally  between 0.3:1 and  3:1, preferably  between 0.7:1 and  2:1.  A mixture of  hydrophobic solvent  and auxiliary amine,  which is formed  substantially from  the organic phase  (R)  leaving the subsequent  extraction stage  (6),  optionally dis› tillate  (M),  optionally  a part volume of  (E)  and generally a  part volume of stream  (S),  serves as the extraction  agent  (J).  Because the aqueous  phase (C) according  to the invention  exhibits a degree  of  protonation greater  than the degree of  protonation preferred  in the aqueous input  phase to the  extraction stage  (5),  it may be necessary  and  advantageous  to adjust such a  preferred degree  of  protonation  in the  aqueous input phase  to the extraction  stage  (5)  by the  addition at a suitable  point of auxiliary  amine and/or  polyamine.  The molarity of the  aqueous phase used  in  (5)  is prefer› ably <2.5. The degree  of  protonation  of the aqueous phase  used in (5) is preferably  <60%.  In an extraction stage  (5)  acting in multi-stage  manner,  operated preferably  at 80° to 100° C.,  the second part  product is extracted  from the aqueous  phase  (H)  in exchange  for auxiliary amine,  optionally after the  addition of water  to  reduce the molarity  and optionally after  the addition of  auxiliary amine to  reduce the degree  of  protonation, and  in  the course thereof  is  transferred into the  organic phase  (L).  A degree of  protonation  of virtually 100%  in the aqueous  phase  (C)  can be achieved only  if  the entire aqueous  phase  passes at least once  by way of the extraction  stage  (6)  and  in so doing is extracted  with virtually pure  hydrophobic  solvent.  The  corresponding second  process product is  to be found  in the aqueous phase  (H)  leaving the extraction  stage (  4).  In the final distillation  stage (7 .2) the remaining  auxiliary  amine, optionally  in addition to the  residual volume  of  hydrophobic solvent,  is separated as the  distillate  (F)  from  the first part product  (G) arising as the  distillation bottoms  and collected in the  process product tank  (10).  The recycled aqueous  phase (C) exhibits  a higher degree  of  protonation than  the aqueous phase  (K)  leaving the  extraction stage  (5).  In the case of degrees  of  protonation  which although higher  than that of  (K)  are <100%, this can  be achieved in that  either the entire aqueous  phase passes  through the extraction  stage (  6)  or only a  corresponding  part  volume which, optionally  having a degree of  protonation  of  100%, affords the  elevated-compared  with (K)---degree  of  protonation  of ( C), as a result  of mixing with the  remainder.  In the first distillation  stage  (7.1)  a distillate  (E)  is  separated which includes  the majority, preferably  almost the  entire volume, of  the  hydrophobic solvent  contained in (D)  or (D’), optionally  in addition to part  of the auxiliary amine  contained therein.  The organic phase  (D) or (D’) is transferred,  optionally  after passing through  the acid washing  stage  (7.0),  into the  at least two-stage  distillation stage  (7.1), (7.2). 