Grant: Alliance Grants

This research project seeks to advance Canadian knowledge on metal-organic frameworks (MOFs) as new tools to optimize efficiency of extraction, separation, purification, and recycling of critical metals (CMs), focusing on rare earth elements (REEs). Targeting three streams, each with their own unique challenges, specific MOFs will be developed for the extraction and separation of REEs from (i) mineral concentrate extraction leachates, (ii) hydrometallurgical purification streams and (iii) secondary sources (electric and electronic waste). Given that REEs are typically solubilized under acidic pH, it is important that the materials used for their extraction and separation are stable under these conditions. Herein, we will explore Zr-based MOFs as a platform for the adsorptive extraction and selective separation of REEs. MOFs are porous materials made of metal nodes bridged by organic linkers, with highly tunable pore size, shape and composition, leading to their potential for highly selective adsorption. Zr-based MOFs are the most water stable MOFs reported with many examples being stable in aqueous solutions from pH 1-11. In this proposal, new Zr-MOFs will be synthesized while known ones will be post-synthetically modified to contain functional groups known to selectively coordinate to REEs such as phenylenedioxy diamide, phthaloyl diamide, and diglycolamide. Developing methods to advance MOFs for hydrometallurgical purification offers promise for improving the efficiency and sustainability of metal extraction and separation processes for CMs. Our team includes researchers with expertise in MOF synthesis (Howarth), organometallic chemistry (Fontaine), analytical separations (Larivière), green and sustainable process engineering (Bougie), extractive metallurgy and mineral processing (Boulanger), and theoretical and computational chemistry (Schreckenbach). Research will be conducted in partnership with Torngat Metals and Recycfluo who will provide extensive expertise and guidance on relevant conditions and challenges associated with REE extraction and separation, as well as mineral and industrial samples to help transition to higher technology readiness levels (TRL).