Method of preparing fluorine-free rare earth metal compounds from such compounds containing fluorine
AssigneeTreibacher Chemische Werke Aktiengesellschaft
InventorLeo Hafner
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Abstract
A rare earth metal salt containing fluorine ions is separated from an acidic solution of the salt in the presence of an amount of boric acid sufficient to sequester the fluorine ions whereby the fluorine ions are bound in the solution and fluorine-free rare earth metal salt is recovered from the solution.
Claims5
A method of producing a fluorine-free rare earth metal compound from a rare earth metal salt containing fluorine, the rare earth metal including cerium, comprising the steps of preparing an acidic solution of the salt in the presence of an amount of boric acid sufficient to sequester the fluorine ions in the salt, the amount of boric acid being determined by the equation
- 4 HF + H.sub.3 BO.sub.3 = 3 H.sub.2 O + HBF.sub.4,
- whereby the fluorine ions are bound in the solution, and separating the fluorine-free earth metal salt from the solution.
Dependencies are inferred from the claim text.