Abstract
With an increasing number of low-grade primary ores starting to be cost-effectively mined, we are at the verge of mining a myriad of low-grade primary and secondary mineral materials. At the same time, mining practices and mineral waste recycling are both evolving towards sustainable near-zero-waste processing of low-grade resources within a circular economy that requires a shift in business models, policies and improvements in process technologies. This review discusses the evolution towards low-grade primary ore and secondary raw material mining that will allow for sufficient supply of critical raw materials as well as base metals. Seven low-grade ores, including primary (Greek and Polish laterites) and secondary (fayalitic slags, jarosite and goethite sludges, zinc-rich waste treatment sludge and chromium-rich neutralisation sludge) raw materials are discussed as typical examples for Europe. In order to treat diverse and complex low-grade ores efficiently, the use of a new metallurgical systems toolbox is proposed, which is populated with existing and innovative unit operations: (i) mineral processing, (ii) metal extraction, (iii) metal recovery and (iv) matrix valorisation. Several promising novel techniques are under development for these four unit-operations. From an economical and environmental point of view, such processes must be fitted into new (circular) business models, whereby impacts and costs are divided over the entire value chain. Currently, low-grade secondary raw material processing is only economic and environmentally beneficial when the mineral residues can be valorised and landfill costs are avoided and/or incentives for waste processing can be taken into account.
Highlights
Important metal and mineral raw materials are deemed “critical” when their risk of supply shortage is high (European Commission, 2017)
At the same time, mining practices and mineral waste recycling are both evolving towards sustainable near-zero-waste processing of low-grade resources within a circular economy that requires a shift in business models, policies and improvements in process technologies
This review discusses the evolution towards low-grade primary ore and secondary raw material mining that will allow for sufficient supply of critical raw materials as well as base metals
Summary
Important metal and mineral raw materials are deemed “critical” when their risk of supply shortage is high (European Commission, 2017). Research and development efforts towards novel metallurgical processes have been mainly focussing on recycling processes (urban mining), but the recovery of metals from secondary resources such as (mineral) waste materials are becoming more and more important as well (Reuter, 2013) The treatment of such secondary raw materials with challenging physicochemical properties requires the use of innovative technologies to extract metals with respect to natural mineral ores (Reck and Graedel, 2012). This approach was driven by many technical, social, legislative and economic factors due to increased complexity of the metal mining and production and waste recycling industries and requires a cross-over of research challenges regarding metal recovery within mineral waste treatment and primary ore extractive metallurgy within a circular economy approach. The transformation towards a circular economy and near-zero-waste processing is ongoing, but there are still many challenges hampering its practical implementation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
