| 摘要 |
1,218,952. Treating water. W. R. GRACE & CO. 6 Feb., 1968 [21 April, 1967], No. 5842/68. Heading C1C. [Also in Division B1] Saline water is treated prior to desalination by evaporation, to inhibit the deposition of scale, by 0À1 to 20 p.p.m. of a polyacrylic acid, or a water-soluble salt thereof, having an average molecular weight of from 1000 to 19,000, preferably 5000 to 13,000, calculated as polyacrylic acid. The salt may be an ammonium salt or an alkali metal, such as a sodium or potassium salt. The polymer is preferably added as an aqueous solution which may also contain other compatible treatment agents such as anti-foam agents, corrosion inhibitors and oxygen scavengers.
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