WaterSolutions Separation of Silica from Liquid Media

Water / Wastewater: Sodium silicate can be removed from water with DOWEX™ 21K XLT strong base anion exchange resin. For streams that have a high organic content and are prone to surface fouling DOWEX™ MARATHON™ MSA anion exchange resin is recommended. Unfortunately, silicate is very weakly ionic, so it is not selectively removed and resin capacity will be limited in the presence of most other anions. See table of selectivity data (24K PDF) . Removal is complicated by the polymeric forms that often occur.

Selective Silica Removal from salt solutions has been described using a metal hydroxide loaded ion exchange resin. DOWEX G-26 (H) resin is a tough and versatile cation resin for this application. See reference below.

Catalysis: Information on catalysts for the inter-conversion of different silica compounds can be found at Silane Inter-Conversion and Processing.

References

"Method of purification of salt solution for electrolysis", Oohara, C.; Matsuoka, T.; Kishi, T. and Okuno, T. of Chlorine Engineers Corp., Ltd. European Patent Application EP 0 987 221 A1 (1999).