Process for the preparation of highly pure anhydrous sodium sulphite.

摘要

Invention patent: b "process for the preparation of anhydrous sodium sulphite, highly pure" d .Process for the preparation of anhydrous sodium sulphite, highly pure, with a content of at least 98% by weight of in ~ 2 ~ s through the drying of sodium sulphite containing water.Where sodium sulfide containing water is heated with an organic solvent which is not miscible in water for 10 to 20 u00b0 C below the melting point of the sodium sulfide containing water.Heated in stages, with stages of temperature of 1 to 10 u00b0 C and duration times of 5 to 15 minutes to 10 u00b0 to 20 u00b0 C above the melting point of sodium sulphite containing water.And heated to the boiling point of the mixture of water, solvent, and the water of recrystallization is distilled by azeotropic distillation, vacuum or under pressure.