METHOD FOR RECLAMATION OF N,N-DIMETHYLACETAMIDE IN PRODUCTION OF HIGH-STRENGTH ARAMID FIBRES Russian patent published in 2014 - IPC C07C231/22 C07C233/05 D01F13/00 

FIELD: chemistry.

SUBSTANCE: invention can be used in reclamation of dimethylacetamide (DMAA). The method of reclaiming N,N-dimethylacetamide when producing high-strength aramid fibres includes neutralisation of starting solutions, fractionation of a stretch bath solution in two columns, vacuum evaporation of the mixture of the still residue of a vacuum evaporation apparatus, vacuum fractionation of the evaporated product of the vacuum evaporation apparatus and a third column to obtain the end product. The starting multi-component mixtures are first separated into mixtures containing lithium chloride and mixtures not containing lithium chloride. Mixtures which do not contain lithium chloride are then separated into mixtures containing DMAA and mixtures which do not contain DMAA. A stream which does not contain lithium chloride - a distillate of the vacuum evaporation apparatus and the third vacuum fractionation column - is fed into the last vacuum fractionation column operating at residual pressure of 0.04-0.15 kgf/cm², where vapour of the dimethylacetamide end product is obtained.

EFFECT: high quality of dimethylacetamide as the end product.

1 dwg