Aqueous phase (H). optionally after the addition of aux› iliary amine, is reacted in neutralization stage (8) with the aqueous solution of a strong base, preferably caustic soda solution. to neutralize the acid contained therein. 

The aqueous phase produced during neutralization is separated and collected in waste water container (15). 

The organic phase produced during neutralization is sepa› rated as stream (J), optionally washed with water in washing stage (9) and worked up in distillation stage (12). 

In the last stage of optionally multi-stage distillation stage (12) the second polyarnine subproduct (L) is separated and collected in process product tank (14). 

Using this variant of the process according to the invention, considerable separating power is produced during the fractionation of polyarnine mixtures and numerous sepa› ration problems are satisfactorily solved. 

In particular, in the first polyamine fraction (G), the relative enrichment of the components preferentially con› tained in this fraction can be specifically varied and maxi› mized. 

The proportion of these components remaining in the second polyamine fraction (L), however. are not minimized in an equivalent manner in accordance with this first variant, but are relatively depleted in a variable manner only down to a concentration whose lower limit depends on the char› acteristic partition equilibrium, for the particular process parameters, of the polyarnine components from (A) between organic phase (B) on entering extractor (6) and aqueous phase (H) on leaving extractor (6). 

By admixing amounts of the second polyamine fraction (L) either as a substream of (J) or as a substream of (L) to the initial arylamine (A). its relative concentration of com› ponents of (G) can be lowered and thus the lower limit of these components in the second subproduct (L) achievable according to this first variant can be shifted via the partition equilibrium. The only slight improvement in separating power produced in this way may be sufficient for certain applications, but it generally places a restriction on the throughput of (A). 

A second variant of the process according to the invention is more advantageous and is preferred as an embodiment. In this variant, in addition, the relative enrichment of the components preferentially contained in second polyarnine fraction (L) can also be specifically varied, largely indepen› dently of the first product fraction, by extracting the aqueous phase (H) produced in extraction stage (6), or at least some of it. in a downstream extraction stage (7) operating on the counterflow principle, using organic phase (0). 

Organic phase (0) consists in general of auxiliary amine and optionally polyamine, the latter preferably having the composition of the second process subproduct (L). 

Use of an organic phase (0) without polyamine results in a polyarnine fraction in the aqueous phase (N) leaving extraction stage (7) in which the relative enrichment of the components preferentially contained in this phase is specifi› cally increased and maximized beyond the enrichment pro› duced in aqueous phase (H), and the concentration of the components enriched in (G) can be minimized, at the expense of the polyarnine concentration in the aqueous phase. 

With polyarnine as a constituent of organic phase (0), phases (M) and (N) leaving process stage (7) have a higher polyamine concentration than use of an organic phase (0) without polyamine, which is energetically more favorable for implementation of the process according to the inven› tion. 

By means of the preferred use of a polyamine with the composition of the second subproduct (L) as a constituent of 

organic phase (0), the relative enrichment of the polyarnine components preferentially contained in the aqueous phase (N) leaving separating stage (7), and thus the second polyarnine fraction (L), can be varied and maximized at a higher and thus advantageous concentration due to estab› lishing an equilibrium with self-amplification of the sepa› rating effect. 

In the simplest and general case, organic phase (0) is formed from at least a substream of stream (F) and option- ally further auxiliary amine and/or polyamine, for example a substream of (L). Similarly, stream (0) may be formed from a substream of (F) and a substream (J") of stream (J), containing polyarnine mixture (L) in addition to optional auxiliary amine. By means of the possible addition of auxiliary amine, described elsewhere, before or in neutral› ization stage (8), an organic phase (J) is produced with a composition which corresponds by and large to organic phase (0), so that it can be used, preferably after passage through washing stage (9), as substream (J"), directly and virtually without any further additives, as organic phase (0) in process stage (7). 

The molarity of the aqueous phase used in downstream extraction stage (7) is in general greater than that of aqueous phase (H) leaving extraction stage (6). Basically. it is possible, however, to modify both the molarity and the degree of protonation, to improve the separating power according to the process. by adding aqueous acid and/or water. optionally also auxiliary amine, to the aqueous phase. 

Basically, it is also possible to increase the molarity by removing water from (H) in a distillation procedure. 

Organic phase (M) resulting from stage (7) is added to organic phase (B) used in extraction stage (6). 

Aqueous phase (N) resulting from stage (7) is taken to neutralization stage (8). 

Using the second variant of the process according to the invention, the relative enrichment or depletion of the two polyarnine fractions finally produced can be specifically varied and maximized. In addition to this qualitatively high versatility and power, the second variant also offers, at least for the second polyamine fraction (L), an energetically favorable embodiment. The expense associated with recov› ering the first polyamine fraction (G) increases more, however, in relative terms the smaller is the amount of (G) with respect to polyamine mixture (A) used, because the remaining concentration of polyarnine (G) is correspond› ingly lower in organic phase (D) which has to be worked up by distillation. 

The effect is particularly useful if the components sepa› rated with (G) are present in only low concentration in the initial mixture (A) and/or are relatively highly enriched in fraction (G), e.g. during separation according to the inven› tion of polyamine mixtures from the diphenylmethane series. 

A partial introduction of initial polyarnine (A) to separa- tion stage (6) via aqueous phase (C) generally causes an increase in the polyamine concentration in (D) and thus a decrease in energy requirements. When implementing the process, however, this reduction is associated with a wors› ening in the qualitative separation results for the first sub- product (G), due to the establishment of an equilibrium between the polyamine in aqueous phase (C) and the polyamine in organic phase (D), so that use is made of this possibility only to a small extent or in cases where there are correspondingly low requirements with respect to separation results. 

The third variant of the process according to the invention is an embodiment which is improved in this respect. Starting 

