| 摘要 |
Cation exchange resins used in water treatment plants may be regenerated by a process wherein the resin is regenerated by a monobasic acid which is subsequently distilled with a polybasic acid or an acid salt of a polybasic acid, the strength and amount of the polybasic acid being such that it expels the monobasic acid from its salts, the monobasic acid being chosen to have a volatility above that of the polybasic acid. Monobasic and polybasic acids exemplified are hydrochloric acid (which may be obtained by distilling sodium chloride and sulphuric acid) and sulphuric acids; also mentioned are nitrous, nitric, acetic and propionic acids; pyrosulphuric, chromic and phosphorus acids, and acid salts of phosphorus. Acids containing impurities may be utilized, for example hydrochloric and sulphuric acids containing chlorine, arsenic, organic substances, iron and salts of other metals. When the more volatile acid is hydrochloric acid, the distillate fractions of low acid content can be used to produce demineralized water for example from sea water. Sea water is added to the regenerating acid and the first distillate fractions are run through an anion exchange bed. This procedure can be utilized for regeneration using parallel or countercurrent flow, and when spent resin is removed from the filters for regeneration. There is reference to using the process of the invention for removal of ferric or aluminium ions from the resin.ALSO:Cation exchange resins used in water treatment plants may be regenerated by a process wherein the resin is regenerated by a monobasic acid which is subsequently distilled with a polybasic acid or an acid salt of a polybasic acid, the strength and amount of the polybasic acid being such that it expels the monobasic acid from its salts, the monobasic acid being chosen to have a volatility above that of the polybasic acid. Monobasic and polybasic acids exemplified are hydrochloric acid, (which may be obtained by distilling sodium chloride and sulphuric acid) and sulphuric acids; also mentioned are nitrous, nitric, acetic and propionic acids, pyrosulphuric, chromic and phosphorus acids, and acid salts of phosphorus. Acids containing impurities may be utilized, for example hydrochloric and sulphuric acids containing chlorine, arsenic, organic substances, iron and salts of other metals. When the more volatile acid is hydrochloric acid, the distillate fractions of low acid content can be used to produce demineralized water for example from seawater. Sea water is added to the regenerating acid and the first distillate fractions are run through an anion exchange bed. This procedure can be utilized for regeneration using parallel or countercurrent flow, and when spent resin is removed from the filters for regeneration. There is reference to using the process of the invention for removal of ferric or aluminium ions from the resin. |
