US 6,440,381 B1Granted

Continuous production of silica via ion exchange

AssigneeCabot Corporation

InventorsDouglas M. Smith, Kevin H. Roderick, Alok Maskara, Kenneth C. Koehlert

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Abstract

A continuous process for the conversion of sodium silicate to silicic acid, wherein a moving bed of a protonated ion exchange resin is contacted with an inlet stream of sodium silicate to provide an outlet stream of silicic acid. The outlet stream of silicic acid produced thereby can be processed into a variety of silica products. The outlet moving bed of spent sodium-enriched ion-exchange resin is continuously regenerated into protonated ion-exchange resin by contacting the spent resin with an inlet stream of acid of sufficient strength to exchange the sodium ions in the spent resin with a proton. The regenerated protonated ion-exchange resin is continuously recycled back into the sodium silicate stream for further production of silicic acid.

Claims15

Dependent claims

A continuous process for the conversion of sodium silicate to silicic acid comprising:

(a) providing a moving bed comprising a protonated ion exchange resin that exchanges a sodium ion in sodium silicate with a proton,
(b) providing an inlet stream of sodium silicate,
(c) contacting said inlet stream of sodium silicate with said protonated ion exchange resin in said moving bed to provide an outlet stream of silicic acid and a moving bed comprising a sodium-enriched ion exchange resin,
(d) providing an inlet stream of acid that exchanges a sodium ion in said sodium-enriched ion exchange resin with a proton,
(e) contacting said inlet stream of acid with said sodium-enriched ion exchange resin in said moving bed to provide a sodium enriched outlet stream and a moving bed comprising a protonated ion exchange resin that exchanges a sodium ion in sodium silicate with a proton, and
(f) recycling said protonated ion exchange resin of step (e) in step (a).

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/231,366Filed 13 Jan 1999 · us provisional application
Priority: 15 Jan 1998
Granted: 27 Aug 2002
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

B01J 39/04
Cation exchange; Use of material as cation exchangers; Treatment of material for improving the cation exchange properties: processes using organic…
B01J 47/10
Ion-exchange processes in general; Apparatus therefor: with moving ion-exchange material; with ion-exchange material in suspension or in…
B01J 49/12
Of moving beds: containing cationic exchangers
C01B 33/1435
Of aqueous solutions of silicates: using ion exchangers