Preparation of silica supported 1-nitroso-2-naphthol-grafted- poly(p-hydroxystyrene) resin for the removal of trace cobalt from acidic solution

Trace cobalt ion in the zinc sulfate electrolyte is the most difficult to be removed among all metallic impurities and has the most detrimental effect on zinc electrowinning. In this study, poly(p-hydroxystyrene) resin was first prepared from polystyrene, and then 1-nitroso-2-naphthol was grafted onto poly(p-hydroxystyrene) resin through -O- group by a series of reactions to obtain the 1-nitroso-2-naphthol-grafted-poly(p-hydroxystyrene) resin. Finally, the grafted resin was supported on SiO2. The supported resin could removal trace cobalt ions with good selectivity and reusability in the zinc sulfate leachate, which can meet the requirements of the industrial electrolytic zinc process.