| 摘要 |
Provided is a method for producing a difluorophosphate, which can easily and industrially advantageously produce a high-purity difluorophosphate . The method includes a step of producing a difluorophosphate in the fluorophosphoric acid solution by reacting hydrofluoric acid anhydride containing no solvent with an oxoacid and/or the like of phosphorous to produce a fluorophosphoric acid solution; a step of adding a hexafluorophosphate to the fluorophosphoric acid solution in the absence of respective halides, carbonates, borates, phosphates, hydroxides, and oxides of an alkali metal and the like; and a step of heating and drying the fluorophosphoric acid solution containing the difluorophosphate to distill away a fluorophosphoric acid, or a step of depositing the difluorophosphate in the fluorophosphoric acid solution by crystallization, subsequently separating the difluorophosphate by solid-liquid separation, and distilling away a fluorophosphoric acid contained in the difluorophosphate after the solid-liquid separation. |
