Processing of spent platinum-based catalysts via fusion with potassium hydrogenosulfate.
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.
Batista
Sebastião Guedes
SG
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.
Afonso
Júlio Carlos
JC
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.
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
D013464:Sulfuric Acids; D007204:Indium; D010984:Platinum; D014001:Tin; D000535:Aluminum; C048813:potassium peroxymonosulfuric acid