METHOD OF PREPARING AQUEOUS SOLUTIONS OF SODIUM HYDROXIDE

摘要

FIELD: caprolactam production. SUBSTANCE: invention relates to improved method for recovering sodium hydroxide aqueous solutions from alkali wastes. Aqueous solutions of alkali waste containing additionally 0.05-0.3 wt % of non-ionic surfactant of general formula R-O-(CHCHO)H, where R is C-C-alkyl or C-C-alkylphenyl, and n = 2-30, undergo electrodialysis giving aqueous solutions containing sodium hydroxide up to 20 wt %, not more than 2.0 wt % soda, and not more than 3 g/L of atmospheric oxygen. EFFECT: improved quality of product.