Silver(I) recovery on sulfur-containing polymeric sorbents from chloride solutions

This work describes the preparation of functional polymers containing 2-mercapto-1-methylimidazole and guanylthiourea ligands from chemically modified vinylbenzyl chloride/divinylbenzene copolymer (VBC/DVB). The resins were used for the removal of Ag(I) from synthetic and real chloride solutions. The 2-mercapto-1-methylimidazole resin was highly selective towards Ag(I) in relation to Pb(II) from real chloride leaching solution. The resins were selective for Ag(I) from real chloride solution and they did not sorb chloride complexes of Co(II), Ni(II) and Zn(II). The sorption kinetic data were well fitted to the pseudo-first-order kinetic model. The degree of Ag(I) desorption was about 80% using 1% potassium cyanide solution in 0.5% hydrogen peroxide solution. Resins retain their capacity towards Ag(I) in five consecutive sorption/desorption cycles.