RECOVERY METHOD OF LITHIUM CHLORIDE, DIMETHYLACETAMIDE AND ISOBUTYL ALCOHOL OR LITHIUM CHLORIDE AND DIMETHYLACETAMIDE FROM PROCESS SOLUTIONS FOR PRODUCTION OF PARA-ARAMID FIBRES Russian patent published in 2016 - IPC B01D61/00 

FIELD: wastewater treatment plants.

SUBSTANCE: invention relates to methods of waste water purifying and organic solvents and mineral substances regeneration and can be used in production of synthetic fibres for recycling of dimethyl acetamide (DMAA), isobutyl alcohol (IBA) and lithium chloride and to establishment of water run-around system. Regeneration method involves stages of DMAA, IBA and water separation by rectification, initial solution neutralization by lithium hydroxide, produced in electrodialysis device with bipolar membranes, sedimentation and filtration of iron hydroxide, electrodialysis concentration in electrodialysis device with non-flowing concentration chambers at current density of 0.5-5 A/dm², part of concentrated lithium chloride solution post-evaporation and its crystallization during cooling in form of solvate with DMAA to return into process for synthetic fibres producing, other part of concentrated lithium chloride solution direction into electrodialysis device with bipolar membranes for lithium hydroxide and hydrochloric acid producing with concentration of 0.1-1 M at current density of 0.5-5 A/dm², direction of partially desalinated solution of DMAA, IBA and water or DMAA and water: to fine purification into electrodialysis device with ion exchange filler in desalination chambers until lithium chloride residual content of 5-50 mg/l, then its direction into rectification to produce pure DMAA and IBA or DMAA and returning concentrate after electrodialysis with ion exchange filler to electrodialyzer input for lithium chloride concentration.

EFFECT: technical result is increased degree of DMAA, IBA and lithium chloride purification for reuse in production of para-aramid fibers.

1 cl, 1 dwg, 11 tbl