| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of purification of a metal fluoride, capable of purifying the metal fluoride such as lithium fluoride, using a hydrogen fluoride solution, to achieve a high purity. SOLUTION: The method of purification of the metal fluoride comprises crystallizing the metal fluoride from the hydrogen fluoride solution containing crude metal and removing impurities to obtain the metal fluoride. The method comprises: a step of precipitating a compound of the formula: MFy-nHF-mH<SB>2</SB>O (wherein y, n and m satisfy the relations: 1≤y≤3, 0≤n≤6 and 0≤m≤6; and M is a metal element) by evaporating at least a portion of hydrogen fluoride from the hydrogen fluoride solution containing the crude metal and concentrating the solution; and a step of separating the compound of the formula: MFy-nHF-mH<SB>2</SB>O (wherein y, n and m satisfy the relations: 1≤y≤3, 0≤n≤6 and 0≤m≤6; and M is a metal element) by filtering the concentrated hydrogen fluoride solution. COPYRIGHT: (C)2009,JPO&INPIT
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