title: Recovery of platinum, tin and indium from spent catalysts in chloride medium using strong basic anion exchange resins.
abstract: This work describes a route for platinum recovery from spent commercial Pt and PtSnIn/Al(2)O(3) catalysts using strong basic mesoporous and macroporous anion exchange resins (Cl(-) form). The catalysts were leached with aqua regia (75 °C, 20-25 min). Platinum adsorption was influenced by the presence of other metals which form chlorocomplexes (tin, indium) and also base metals (aluminum). However, it was possible to overcome this fact by a sequential desorption procedure. Aluminum was selectively removed from the resins by elution with 3 mol L(-1) HCl. Platinum was desorbed passing 1 mol L(-1) Na(2)S(2)O(3) (pH 9). Tin was removed by elution with 0.1 mol L(-1) ascorbic acid. Indium was removed using 0.1 mol L(-1) EDTA as eluent. Desorption efficiency exceeded 99% for all metals. Metals were recovered in high yields (>98 wt%).
authors.affiliation: Analytical Chemistry Department, Institute of Chemistry, Federal University of Rio de Janeiro, Av Athos da Silveira Ramos, 149 room A509, 21941-909 Ilha do Fundão, Rio de Janeiro, Brazil.
authors.forename: Roberta Santos
authors.initials: RS
authors.lastname: Marinho
authors.forename: Cristiano Nunes
authors.initials: CN
authors.lastname: da Silva
authors.forename: Julio Carlos
authors.initials: JC
authors.lastname: Afonso
authors.forename: José Waldemar Silva Dias
authors.initials: JW
authors.lastname: da Cunha
mesh_terms: D000327:Adsorption; D000535:Aluminum / Q000032:analysis; D000837:Anion Exchange Resins; D000838:Anions; D001205:Ascorbic Acid / Q000737:chemistry; D002384:Catalysis; D002712:Chlorides / Q000032:analysis*; D004492:Edetic Acid / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007204:Indium / Q000032:analysis*; D008670:Metals / Q000032:analysis; D008956:Models, Chemical; D010984:Platinum / Q000032:analysis*; D014001:Tin / Q000032:analysis*
chemical_list: D000837:Anion Exchange Resins; D000838:Anions; D002712:Chlorides; D008670:Metals; D007204:Indium; D010984:Platinum; D014001:Tin; D004492:Edetic Acid; D000535:Aluminum; D001205:Ascorbic Acid