Production method and fluoridation niobium acid kalium crystal of fluoridation niobium acid kalium crystal

摘要

Although being profitable in the aspect of raw materials cost and raw materials melting operation, to produce at high yield it is possible the fluoridation niobium acid kalium crystal of large grain size and Takasina rank production method and fluoridation niobium acid kalium crystal of fluoridation niobium acid kalium crystal are disclosed. This production method, (a) adding kalium type electrolyte to the raw materials liquid which contains niobium, roughly oxy fluoridation niobium acid kalium crystal and/or making fluoridation niobium acid kalium crystal precipitate roughly, the first process which the said roughly crystallizes difference and, (b) after heating the recrystallization solvent which consists of the aqueous solution which 12 - 35 weight % contains hydrofluoric acid above the 50C, the description above melts crystal in the said recrystallization solvent roughly, at descending/disembarking warm speed under 20C/h includes with the descending/disembarking second process which warm is done below the 40C and becomes.