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Abstract

A process suitable for producing high purity alkaline earth fluoride product is disclosed which involves (a) mixing (i) MgO, CaO, BaO, Mg(OH).sub.2, Ca(OH).sub.2, and/or Ba(OH).sub.2, (ii) NaOH, KOH and/or NH.sub.4 OH, and (iii) water, to form an aqueous slurry having a temperature of at least 20.degree. C. and an aqueous phase pH of at least 13; (b) adding fluosilicic acid, optionally adding additional water and optionally adding additional NaOH, KOH and/or NH.sub.4 OH to the slurry of (a) at a rate which maintains an aqueous phase pH of 11 or above, and in an amount to provide a molar ratio of Si: (Mg, Ca, and Ba) of at least 1:3.3, a molar ratio of (Na, K, and NH.sub.4):Si of at least 2:1, and a molar ratio of water:Si of at least 20:1, and to obtain a precipitate comprising an alkaline earth fluoride (MgF.sub.2, CaF.sub.2 and/or BaF.sub.2), and an aqueous solution of a soluble silicon anionic compound; and (c) recovering the alkaline earth fluoride product.

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First Claim