1 This is a post-review version of the article published on Waste Management & Research 02/2013; 568-576; DOI:10.1177/0734242X13476364 An environmentally friendly process for the recovery of valuable metals from spent refinery catalysts Laura Rocchetti a * , Viviana Fonti a , Francesco Vegliò b , Francesca Beolchini a *l.rocchetti@univpm.it a Department of Life and Environmental Sciences, Università Politecnica delle Marche, Ancona, Italy b Department of Chemistry, Chemical Engineering and Materials, Università dell’Aquila, 67040 Monteluco di Roio, Italy Abstract The present work deals with the whole valorisation process of exhaust refinery catalysts, including metal extraction by ferric iron leaching and metal recovery by precipitation with sodium hydroxide. In the leaching operation we determined the effects on metal recovery of the concentration and kind of acid, the concentration of catalyst and iron (III). The best operating conditions were 0.05 mol/L sulphuric acid, 40 g/L iron (III), 10% catalyst concentration: almost complete extraction of nickel and vanadium, and 50%extraction efficiency of aluminium and less than 20% for molybdenum. Sequential precipitation on the leach liquor showed that it was not possible to separate metals through such approach and a recovery operation by means of a single stage precipitation at pH 6.5 would simplify the procedures and give a product with an average content of Fe (68%), Al (13%), V (11%), Ni (6%), Mo (1%) potentially interesting in the iron alloy market. The environmental sustainability of the process was also assessed by means of life cycle assessment and allowed to estimate that the highest impact was in the category of global warming potential with 0.42 kg carbon dioxide per kg recovered metal. Keywords Spent catalyst, ferric iron leaching, metal recovery, life cycle assessment, environmentally friendly process, global warming.