title: Processing of spent platinum-based catalysts via fusion with potassium hydrogenosulfate.
abstract: This work describes a route for processing spent platinum-based commercial catalysts (Pt and PtSnIn/Al(2)O(3)) via fusion with potassium hydrogenosulfate (KHSO(4)). Samples were previously ground. The optimized experimental parameters were: temperature, 450°C; time, 3h; sample/flux mass ratio, 1/10. The fused mass was dissolved in water and the elements present were isolated by a multi-step separation procedure. Platinum was recovered as the only water-insoluble residue. About 45 wt% of aluminium was recovered as KAl(SO(4))(2)·12H(2)O (alum), whereas the remaining element was recovered as Al(OH)(3). Tin and indium were recovered together as sulfides at pH 1. About 72 wt% of potassium was recovered as K(2)SO(4) when the final effluent was treated with sulfuric acid (pH 1) and slowly evaporated. Generation of final wastes was greatly reduced. More than 98 wt% of the elements present in the catalysts examined was recovered.
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: Sebastião Guedes
authors.initials: SG
authors.lastname: Batista
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. Electronic address: julio@iq.ufrj.br.
authors.forename: Júlio Carlos
authors.initials: JC
authors.lastname: Afonso
mesh_terms: D000535:Aluminum / Q000737:chemistry / Q000302:isolation & purification; D002384:Catalysis; D003460:Crystallization; D004563:Electrochemistry; D007204:Indium / Q000737:chemistry / Q000302:isolation & purification; D010984:Platinum / Q000737:chemistry / Q000302:isolation & purification*; D013464:Sulfuric Acids / Q000737:chemistry*; D013696:Temperature; D014001:Tin / Q000737:chemistry / Q000302:isolation & purification; D018505:Waste Management; D014961:X-Ray Diffraction
chemical_list: D013464:Sulfuric Acids; D007204:Indium; D010984:Platinum; D014001:Tin; D000535:Aluminum; C048813:potassium peroxymonosulfuric acid