Pt and Al Recovery from a Spent Pt/Al₂O₃ Catalyst via an Integrated Soda Roasting–Alkaline Leaching–Carbonization Process

Abstract

An integrated soda roasting–alkaline leaching–carbonization process was developed to recover platinum (Pt) and aluminum (Al) from a spent Pt/Al2O3 catalyst. A product with the main component of NaAlO2 was obtained under the optimal roasting conditions of the mass ratio of Na2CO3 to spent catalyst 1, roasting time 2 h and roasting temperature 900 °C. The Al in the roasted residue was effectively leached in a dilute NaOH solution, while Pt was enriched in the leached residue with a Pt content that reached 29.4%, and the calculated concentration factor of Pt yielded 79.4. After carbonization was performed for the leached solution, 99.0% of the Al was recovered as the pseudo-boehmite product, which could be used as the feed for preparing the Al2O3 carrier. Pt and Al2O3 in the spent catalyst were selectively separated and enriched using the above process, which thus has good application prospects.

Keywords

• spent Pt/Al₂O₃ catalyst
• soda roasting
• alkaline leaching
• carbonization
• pseudo-boehmite