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US 4,567,027 AGranted
Process for defluorinating an acid sulphate solution
AssigneeMetallurgie Hoboken-Overpelt
InventorsJacquy J. C. Detournay, Jozef V. M. Sterckx
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Abstract
A process for defluorinating a solution of a sulphate of Zn, Ni, Cd, Mn and/or Mg, in which Al.sup.3+ and PO.sub.4.sup.3- ions are added to the solution, then the solution is neutralized up to a pH higher than 4 and lower than that one that causes a substantial precipitation of Zn, Ni, Cd, Mn and/or Mg, thereby producing a fluorinated precipitate, and the precipitate is separated from the solution.
Claims11
A process for separating F.sup.- ions from an acid aqueous solution of ZnSO.sub.4, comprising the steps of
- (a) adding Al.sup.3+ and PO.sub.4.sup.3- ions to the solution so that the solution contains at least about 1 g/l of Al.sup.3+ and at least about 3.5 g/l of PO.sub.4.sup.3- ;
- (b) neutralizing the solution up to a pH higher than 4 and lower than about 5 and a temperature of between about 45.degree. and 90.degree. C., thereby forming a fluorinated precipitate and by separating
- (c) filtering said fluorinated precipitate from the solution, thereby producing a partially defluorinated solution.
Dependencies are inferred from the claim text.