Alkaline-type anion exchange resin

Anion-exchange resins may be used for the peeling-type of alkaline-degradation reactions, as shown by the formation of D-glucose from tu-ranose - (S-O-a-D-glucopyranosyl-D-fructose) on treatment with such materials. 

The two types of resins can be located in separate tanks. In this system, the two tanks are operated in series in a cation-anion sequence. The anion resin is regenerated after exhaustion with a solution of sodium hydroxide. The cation resin is regenerated with an acid, either hydrochloric or sulfuric. Some leakage of cations always occurs in a cation exchanger, resulting in leakage of alkalinity from the anion exchanger. 

If it is necessary to extract the rare metal from an acid or alkaline leach liquor, or similar solution, a resin should be selected which is known to be stable in the leaching reagent. For extraction of the rare metal ion itself, the resin would normally be of the cation-exchange type, unless the rare metal ion could be converted to an anionic complex. However, the possibility of designing a process in which the impurities are absorbed by the resin and the rare metal remains unextracted, should not be neglected. An example of this type has been developed by Ayres,i > in which iron, titanium, lanthanum and beryllium impurities are extracted from a zirconium nitrate solution by operation at a pH where the zirconium is converted to a non-ionic hydrated oxide sol. 

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