| 摘要 |
<p>A mixture of H2SO4 and a cpd. (I) is used to regenerate strongly acid, finely divided, cation-exchange resins in the H-form. (I) is cpd. which forms halide ions (concn. at least 0.01 moles/l.) and forms a water-soluble sulphate; preferably HCl aq. (conc. 0.01-2.0 moles/l) or a chloride (concn. 0.01-0.5 moles/l). Suppression of the precipitation of CaSO4. Divinyl-benzol-styrene-copolymer cation exchange resin, used for water softening, contained 75% Ca2+ and 25% Na+. Treatment with 0.35N H2SO4 in mole-ratio 1.6:1 gave considerable precipitation of CaSO4 resulting in contamination of the resin. Treatment with H2SO4 with sufficient HCl aq. to give 0.02M HCl concn. gave no precipitate.</p> |
