POLY(4-VINYLPYRIDINE) GEL-COATED ON SILICA - HIGH-CAPACITY AND FAST KINETICS IN URANYL SULFATE RECOVERY

A new process has been developed for gel-coating a weak-base resin poly(4-vinylpyridine) as a lightly cross-linked thin layer on high surface area silica to produce a granular sorbent, designated as SiO2..[PVP.XQ]. The gel-coating of the resin affords nearly 80% attainment of its theoretical capacity and provides fast sorption kinetics and nearly instantaneous stripping as compared to conventional weak- and strong-base resins which give much lesser values in the sorption of UO2SO4 from dilute aqueous solutions at a relatively high pH (greater-than-or-equal-to 4). The conventional bead form resins used for comparison are poly(4-vinylpyridine) Reillex HP, nearly 70 % quaternized poly(4-vinylpyridine) Reillex HPQ, and a quaternary ammonium-type strong-base resin Dowex-1x8. The sorption kinetics on SiO2-[PVP.XQ] is found to be diffusion controlled with a high value of 5.4 x 10(-6) cm2/s for the product of distribution coefficient and effective diffusivity.