混合二氟包括杂质磷酸盐和碱金属或碱土金属的碳酸盐，氢氧化物和卤化物与胺，至少一种选自下组的治疗剂，以及具有分离杂质二氟的工序 公开了一种纯化磷酸盐的方法。 优选杂质和处理剂混合形成盐或络合物，然后通过过滤过滤分离盐或络合物。 优选地，作为处理剂，使用碱金属的碳酸盐，氢氧化物或卤化物，更优选使用锂的碳酸盐，氢氧化物或卤化物。

Mixing difluoro including impurities phosphate and the alkali or alkaline earth metal carbonates, hydroxides and halides and amines, at least one kind of a treating agent selected from the group consisting of, and having a step of separating the impurity-difluoro to discloses a purification method of phosphate. After forming a salt or complex, a mixture of the impurities with the treatment agent, it is preferred that the filtration is a salt or complex by filtration. Preferably a treating agent, use of an alkali metal carbonate, hydroxide or halide, more preferably lithium carbonate, hydroxide or halide.