Investigation into sorption processes of pyrazole-containing resins with respect to metals of the platinum group

The results of investigations into increasing the capacitive characteristics of pyrazole-containing sorbents for the recovery of palladium and platinum from their acidic solutions are presented. For these purposes, a sorbent of the SVPD grade with a microporous structure based on N -vinyl-3(5)-methylpyrazole and divinylbenzene is synthesized and tested and its capacitive characteristics by palladium and platinum are determined. The comparative tests of the SVPD resin with a pyrazole-containing sorbent of the SDP-d grade with a macroporous structure obtained based on styrene divinylbenzene and 3(5)-methylpyrazole in the presence of the deprotonating additive are performed at various acidities of the starting solutions. It is shown that the sorbent of the SVPD grade is preferable due to its capacitive characteristics when compared with the macroporous SDP-d sorbent. Optimal acidities of the starting solutions for the recovery of palladium and platinum by the sorbents under study are established. Two samples of bifunctional resins containing groups of N-vinyl-3(5)-methylpyrazole and organic sulfides are synthesized. The results of their tests showed that the introduction of organic sulfides into the resin not only leads to an increase in the sorbent capacity by palladium, but also considerably widens the working acidity range of the solutions.