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.

A roast-leach process has been developed for concentrating platinum (Pt) from a spent Pt-Al₂O₃ catalyst. The effects of (NH₄)₂SO₄ to spent catalyst mass ratio, roasting temperature and roasting time on the Pt enrichment factors were investigated. The results showed that the optimized roasting conditions were (NH₄)₂SO₄ to spent catalyst mass ratio of 7.5, roasting temperature of 350 °C and roasting time of 5 h. The roasted product was mainly comprised of soluble NH₄Al(SO₄)₂ and Al₂(SO₄)₃ according to XRD analysis. The roasted product was leached in sulfuric acid to remove the soluble sulfates, and meanwhile Pt was kept in the residue. Under optimized conditions, a Pt concentrate with Pt content of 73.2% could be obtained from the spent catalyst with 0.27% Pt, and the corresponding Pt enrichment factor was more than 270.

DNA and RNA simultaneously extracted from A. f using the optimised method. (a) Total nucleic acid extracted from A. f : lane M1, 1 kb ladder; lane M2, Hind III-cut lambda molecular size marker; lanes 1–4, biological replicates. (b) DNA precipitated by isopropanol. (c) RNA precipitated by LiCl.