Alumina compounds in ion exchange resins
AssigneeThe Dow Chemical Company
InventorsJohn M. Lee, William C. Bauman
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Abstract
Formation of hydrous alumina in the reticules of a weak-base anion exchange resin, wherein AlCl.sub.3 has been precipitated as hydrous alumina by reaction with ammonia, is improved by employing a subsequent treatment with HCl or with NH.sub.4 Cl and HCl to convert the exchange resin to the chloride form, thereby increasing the reticular volume of the resin, thus permitting subsequent precipitation of additional hydrous alumina therein.
Claims12
In a process for precipitating Al(OH).sub.3 in the reticules of a weak-base anion exchange resin by the in situ ammonia precipitation of Al halide in aqueous media, thereby forming a composite consisting essentially of anion exchange resin having Al(OH).sub.3 dispersed therein, the improvement which comprises the additional steps of
- 1. slightly acidifying the so-formed composite in an aqueous medium with HX, X being halide, where the amount of HX is an amount sufficient to provide an acid pH of not lower than about 5.0, thereby converting the anion exchange resin to the halide salt form,
- 2. substantially separating the composite from the aqueous portion,
- 3. substantially flooding the composite with an aqueous solution of Al halide, draining the excess solution, and
- 4. adding NH.sub.4 OH to precipitate additional Al(OH).sub.3 in the resin.
Dependencies are inferred from the claim text.