Rare Metal Extraction & Processing: REEs
Sponsored by: TMS Extraction and Processing Division, TMS: Hydrometallurgy and Electrometallurgy Committee
Program Organizers: Gisele Azimi, University of Toronto; Takanari Ouchi, University of Tokyo; Kerstin Forsberg, KTH Royal Institute of Technology; Hojong Kim, Pennsylvania State University; Shafiq Alam, University of Saskatchewan; Alafara Baba, University of Ilorin; Neale Neelameggham, IND LLC

Tuesday 8:30 AM
March 16, 2021
Room: RM 44
Location: TMS2021 Virtual


8:30 AM  Keynote
Innovative Reactors for Recovery of Rare Earth Elements (REE): Alison Lewis1; Jemitias Chivavava1; Jacolien DuPlessis1; Dane Smith1; Jody-Lee Smith1; 1University of Cape Town
    Interest in the recovery of Rare Earth Elements (REE) has increased dramatically in the last few years, with a surge in research activity and publications focussing on recovery of REE [1-7]. The recovery is often achieved using staged precipitation processes carried out in various configurations of stirred tank reactors [5] such as the parallel flow precipitation method [7]. Although it is known that stirred tank reactors are not always the most suitable choice for precipitation processes, they are inevitably the default choice in both industrial processes and research studies. This keynote address will propose that innovation is needed in the choice and design of precipitation reactors in order to most effectively recover REE and to design efficient, controllable and sustainable processes.

8:50 AM  Invited
Study of the Recovery of Rare Earth Elements from Ion Adsorption Clays through Perolation Leaching Processes: Jochen Petersen1; Megan Becker2; Chad Naude2; 1University of Cape Town; 2Univ of Cape Town
    The extraction of rare earth elements (REEs) from ion adsorption clays (IACs) provides for around 30% of the World’s REE supply. The REEs are extracted through conventional ion-exchange lixiviants such as (NH4)2SO4 and MgSO4 in percolation type processes. This study focuses on using in-situ and heap leaching technology for REE extraction. An in-situ leaching approach envisages injecting leach solutions into clay deposits and draining solution from REE deposits through a series of narrowly spaced wells. In heap leaching agglomerated and structurally stabilised pellets of clay are stacked on dedicated leach pads.In either case the extraction of REEs is governed by a combination of desorption-diffusion and transport processes. The results of this study show that if sufficient channels for solution percolation through the clay bed can be created, or clay pellets remain competent for the duration of a heap leach process, high extraction of REEs is possible.

9:10 AM  
Recovery of Rare Earth Elements from Recycled Hard Disk Drive Mixed Steel and Magnet Scrap: Tedd Lister1; Michelle Meagher2; Mark Strauss1; Luis Aldana1; Harry Rollins1; 1Idaho National Laboratory; 2Colorado School of Mines
    Recycling e-scrap is an important source of critical materials. Traditional recycling routes for e-scrap focus on the recovery of silver and gold. However, value can be attained by recovering of rare earth elements. This paper describes a process for the recovery of rare earth elements from hard disk drives using HCl as a re-usable extraction medium. The mixture was selectively leached using HCl to remove the magnet alloy from shredded hard disk drives. The magnet and steel dissolution rate were examined for various HCl concentrations. Recovery of rare earth hydroxides was over 80%. Finally, reused HCl recovered up to 70% rare earth elements.

9:30 AM  Invited
Extraction Chromatography for Separation of Rare Earth Elements: Meher Sanku1; Kerstin Forsberg1; Michael Svärd1; 1KTH Royal Institute of Technology
    Developing efficient and viable processes for separation of critical metals is essential to meet the increasing demand. Rare earth elements (REE:s) are identified by the EU as critical resources, and moreover they are difficult to separate due to their similar properties. Extraction chromatography is a powerful method suitable for difficult, high-purity separations, which could form part of a separation process for recovery of REE:s from various sources. In the present work, separation of REE:s from aqueous leach solutions of apatite is investigated using physically immobilized extractants. By means of reverse-phase columns, reversibly functionalized by acidic organophosphorus compounds, the metals are separated by elution with nitric acid solution.

9:50 AM  Invited
Tool and Workflow for Systematic Design of Reactive Extraction for Separation and Purification of Valuable Components: Hana Benkoussas1; David Leleu1; Swagatika Satpathy1; Zaheer Shariff1; Andreas Pfennig1; 1University of Liège
    Rare-earth metals e.g. recycled from electronic waste in the context of urban mining can be separated and purified utilizing reactive extraction. Process design then aims at optimal selection of reactive extractant, diluent, possible additional components, as well as all process parameters. This requires a deep understanding of the CHEMISTRY of the underlying complexations as well as ENGINEERING expertise on extraction-process as well as equipment design.To solve this design task a tool was developed based on cascaded option trees, which combines the expertise from both sciences. Process design is on the one hand supported by a prototypic work flow and on the other hand by systematically structured and quantitative information on the underlying thermodynamics. The method is also applicable for extraction of diluted components from aqueous solutions as encountered in fermentation broth in the context of bio-economy. The method will be presented and applied to examples from urban mining.

10:10 AM  Invited
Rethinking Mineral Processing and Extractive Metallurgy Approaches to Ensure a Sustainable Supply of High-tech and Critical Raw Materials: Yousef Ghorbani1; Glen Nwaila2; Steven Zhang3; Jan Rosenkranz1; 1Luleå University of Technology; 2University of the Witwatersrand; 3PG Techno Wox, 43 Patrys Avenue, Helikon Park
    Raw materials (RM) are crucial for the operation of the economy especially in industrialized regions. The 4th industrial revolution and the energy transition are reliant on access to certain RM. High-tech RMs these seldom the primary constituent of ore deposits. Instead, they are overwhelmingly extracted as by-products. To increase the production of rare high-tech RM, it is essential to modify the existing bulk RM production process and extract the target materials from partial, secondary, or waste streams. This study aims to present and discuss the necessities of redefining the concept and scope in mineral processing and extractive metallurgy approaches in order to secure a sustainable supply of high-tech and critical raw material (CRM) for the economy in modern society. A list of paths and trends for developing future concepts and methods in mineral processing and extractive metallurgy will be introduced in pursuance of gaining access to high-tech and CRM from both primary and secondary resources.

10:30 AM  Invited
Extraction of Rare Earth Metals: The New Thermodynamic Considerations towards Process Hydrometallurgy: Ajay Patil1; Rudolf Struis1; Andrea Testino2; Christian Ludwig1; 1Paul Scherrer Institut and École Polytechnique Fédérale de Lausanne; 2Paul Scherrer Institut
    Successful management of secondary waste resources is essential for the viable circular economy. E-waste could serve as the potential urban mining source for the alternative supply chain of critical metals such as rare earth elements (REEs). The hydrometallurgical processes for REEs are mainly designed for mining. Conventional approaches lack the sustainability, and economic and value chain based aspects important in the current era with increasing pressure to reduce environmental impact. We have performed the thermodynamic calculations to simulate the solution chemistry behaviour of REEs such as Neodymium (Nd), Dysprosium (Dy) and Praseodymium (Pr) present in NdFeB magnets. Our calculations have suggested that we could exploit the differences in solution properties of REE hydroxides by precisely controlling the hydrometallurgical methods and then to separate the REEs further using extractive processes.