| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a difluorophosphate capable of easily and industrially advantageously producing a difluorophosphate with high purity.SOLUTION: Provided is a method for producing a difluorophosphate comprising: a step of reacting a hydrofluoric acid aqueous solution with the oxy-halide of phosphorous (excluding trifluorophosphine oxide) to produce coarse difluorophosphoric acid; a step of reacting alkali metal, alkaline-earth metal and the halide of aluminum or onium with the rough difluorophosphoric acid to produce a difluorophosphate in the rough difluorophosphoric acid; and a step of heating and drying the coarse difluorophosphoric acid including the difluorophosphate to distillate the difluorophosphoric acid or a step of precipitating a difluorophosphate in the rough difluorophosphoric acid by crystallization, thereafter subjecting the difluorophosphate to solid/liquid separation and further distillating the rough difluorophosphoric acid included in the difluorophosphate after the solid/liquid separation. |
