Co-processing of sulfidic mining wastes and metal-rich post-consumer wastes by biohydrometallurgy

• Published in: Minerals engineering 2015-05, Vol.75, p.45-53
• Main Authors: Guezennec, Anne-Gwénaëlle, Bru, Kathy, Jacob, Jérôme, d’Hugues, Patrick
• Format: Article
• Language: English
• Subjects: Bioleaching; Chemical and Process Engineering; Co-processing; Engineering Sciences; Mining wastes; PCBs; WEEE
• ISSN: 0892-6875; 1872-9444
• DOI: 10.1016/j.mineng.2014.12.033

•Bioleaching of sulfidic mining wastes enables to produce lixiviant solution that can be used further for e-wastes leaching.•Biological re-oxidation of iron greatly enhances metals dissolution kinetics and yields during PCBs leaching.•Copper extraction above 90% was achieved in 24h of PCBs leaching.•Microbiologically assisted leaching of waste PCBs is a promising way for metals recycling.•Decoupling the lixiviant production from the leaching process enables to avoid toxicity issues. The consequence of a strong economic growth in emerging countries combined with the rise of the world population is an increase in the demand for raw materials, leading to growing concern regarding their availability and the global efficiency of the supply chain. These tensions reinforce the need to associate the development of the recycling industry to the identification of new resources which could be used for the recovery of valuable materials. The purpose of this study is to develop a novel biological co-processing approach for the recovery of strategic metals in both sulfidic mining wastes and post-consumer wastes (WEEE). The principle of this treatment is based on two steps: mine wastes are biologically oxidized, resulting in the production of a ferric iron-sulfuric acid lixiviant solution which is used to leach base and other soluble metals contained in e-scraps. Batch tests were carried out using flotation tailings wastes containing 60% of pyrite and grinded Printed Circuit Boards (PCB