|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Rare Metal Extraction & Processing
||Study of the recovery of rare earth elements from ion adsorption clays through perolation leaching processes
||Jochen Petersen, Megan Becker, Chad Naude
|On-Site Speaker (Planned)
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.