| 摘要 |
<p>A process for producing an anhydrous dithionite which comprises reacting formic acid or a formate, an alkaline compound and sulfur dioxide in the presence of water and an organic solvent, filtering the resulting dithionite crystal from the mother liquor, washing the dithionite crystal with an organic solvent and drying the dithionite crystal, characterized in that in the washing step, the washings first discharged are distilled by a convention method for recovery of the organic solvent, the washings discharged subsequently being used as the reaction solvent without distillation.</p> |
