Staged electrochemical treatment guided by modelling allows for targeted recovery of metals and rare earth elements from acid mine drainage.

Autor: Brewster ET; Kinetic Group Worldwide Pty Ltd, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, QLD, 4556, Australia; Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, St Lucia, QLD, 4072, Australia., Freguia S; Advanced Water Management Centre, The University of Queensland, St Lucia, QLD, 4072, Australia., Edraki M; Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, St Lucia, QLD, 4072, Australia., Berry L; Advanced Water Management Centre, The University of Queensland, St Lucia, QLD, 4072, Australia., Ledezma P; Advanced Water Management Centre, The University of Queensland, St Lucia, QLD, 4072, Australia. Electronic address: p.ledezma@awmc.uq.edu.au.
Jazyk: angličtina
Zdroj: Journal of environmental management [J Environ Manage] 2020 Dec 01; Vol. 275, pp. 111266. Date of Electronic Publication: 2020 Aug 23.
DOI: 10.1016/j.jenvman.2020.111266
Abstrakt: Acid mine drainage (AMD) is a challenge for current and legacy mining operations worldwide given its potential to severely harm ecosystems and communities if inadequately managed. Treatment costs for AMD are amongst the highest in the industrial wastewater treatment sector, with limited sustainable options available to date. This work demonstrates a novel chemical-free approach to tackle AMD, whereby staged electrochemical neutralisation is employed to treat AMD and concomitantly recover metals as precipitates. This approach was guided by physico-chemical modelling and tested on real AMD from two different legacy mine sites in Australia, and compared against conventional chemical-dosing-based techniques using hydrated lime (Ca(OH) 2 ) and sodium hydroxide (NaOH). The electrochemical treatment demonstrated the same capacity than Ca(OH) 2 to neutralise AMD and remove sulfates, and both were significantly better than NaOH. However, the electrochemical approach produced less voluminous and more easily settleable sludge than Ca(OH) 2 . Moreover, the staged treatment approach demonstrated the potential to produce metal-rich powdered solids with a targeted composition, including rare earth elements and yttrium (REY). REY were recovered in concentrations up to 0.1% of the total solids composition, illustrating a new avenue for AMD remediation coupled with the recovery of critical metals.
(Copyright © 2020 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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