| abstract |
A process for the purification of a mixture of aromatic polyamines obtained by hydrogenation of the corresponding aromatic polynitro compounds, said mixture including the various isomers of the said amines as well as reaction by-products, including the steps of carrying out a distillation of the mixture in a distillation column, wherein a first stream, corresponding to a fraction or to all of the stream recovered at the bottom of the distillation column, is separated and is used in a chemical reaction and a second stream is separated corresponding (i) to a stream drawn off from the side in the gas phase, in the lower third of the said column, this stream representing at most 20% or more than 80% of the total volume (first and second stream); or (ii) to a fraction of the first stream, this fraction representing 2 to 50% of the volume of the first stream; in order to treat it subsequently. |