GB672626A - Improvements relating to materials for rendering sea water potable - Google Patents

Abstract

A silver cation-exchange resin for use, e.g., as a disrupting agent in, or principal ingredient of, a briquette for rendering sea-water potable (see Group I) is prepared by sulphonating a copolymer of styrene and divinyl benzene, crushing the product, and converting it to the silverexchanging condition by soaking in silver nitrate solution, rinsing and drying. Specifications 571,029, 577,449, [Group I], 577,707, and 605,174, [Group III], are referred to.ALSO:A silver cation-exchange copolymer of a mono-vinyl aryl compound and a di-vinyl aryl compound is used, preferably as a disrupting agent, in a briquette suitable for use in rendering sea-water potable by silver cation-exchange. The silver cation-exchange resin may be regarded as part of the exchange material forming the principal ingredient of the briquette, the other part of the exchange material consisting preferably of a silver alumino-silicate preferably prepared as described in Specification 605,174, [Group III]. The silver cation-exchange resin may constitute from 0.5 to 70 per cent by weight of the briquette, but preferably 1 to 10 per cent; between these narrower limits it acts primarily as the disrupting agent having a lower exchange capacity than the silver alumino-silicate. The resin may be a copolymer of styrene and divinyl benzene of the kind described in Specifications 571,029 and 577,707 is preferably a sulphonated copolymer of this kind, and is converted to the silver-exchanging condition by soaking in silver nitrate solution, rinsing and drying. It is preferably ground to a size such that it will pass through a U.S. standard 100-mesh sieve. A briquette having a total weight of 68.1 grams had the following composition: silver cation-exchange resin 1.3 grams, silver alumino-silicate 62.3 g., stearic acid (briquetting lubricant) 0.8 g; activated carbon 0.2 g., barium hydrate 3.5 g. All the ingredients were mixed dry and compressed under a pressure of between 12 and 16 tons per square inch to form a briquette about 3.0 cubic inches in volume. The "disruption time" and "filter time" of the briquette are less and the ion exchange capacity of the values for briquettes using bentonite or Fuller's earth as a disruption agent. Specification 577,449 also is referred to.