| 摘要 |
1331948 Regenerating Ion-exchange resins INSTITUTUL DE PROIECTARI PENTRU INDUSTRIA OHIMICA ANORGANICA SI A INGRASAMINTELOR 9 Oct 1970 [11 Oct 1969] 48135/70 Heading B1J [Also in Division C1] Cationic or anionic ion-exchange resin beads are regenerated with relatively concentrated acid or base respectively, the temperature volume and rate of flow of the regenerant and the thickness of the resin layer being such that the temperature at the surface of he resin beads does not exceed 20‹C. Under these conditions, the resin does not deteriorate excessively. Sulphonated styrene-divinyl-benzene macroporous resins are particularly resistant, especially when sulphonation has been carried out at not more than 100‹C, and regeneration may be effected with 50% nitric acid. Regeneration may take place in the annular space between perforated tubes 1 and 4, lined with metal screens 9, in a vessel 2. The resin is hydraulically loaded through an inlet b and the carrier liquid is removed through an outlet c by vacuum. The regenerant is introduced through inlets a 1 , a 2 and subsequently removed through outlet c. Remaining traces may be removed by suction or, through an outlet d, by blowing in air or inert gas, and then by rinsing with demineralized water introduced through the inlets a 1 , a 2 . Regenerated resin is returned to the ionexchange reactor through the inlet b by the introduction of water and air through outlets d and c. A complete apparatus is described, Fig. 3 (not shown), for removal of ammonium cation and nitrate anion using separate cation and anion exchange reactors (4 1 and 4 2 ) and a final mixed-bed reactor (7). The two main reactors are each associated with a regenerating apparatus (9 1 and 9 2 ) as shown in Fig. 2, the regenerants being 56% nitric acid and 10-20% ammonia solution respectively. The use of this apparatus for the treatment of condensates in the production of ammonium nitrate and in the production of complex fertilizers by the Norsk-Hydro process is also described (see Division C1). |
