REVIEW OF RECENT WORK ON THE RECOVERY OF RARE EARTH ELEMENTS FROM SECONDARY SOURCES Final report No. R1859 Submitted to: Natural Resources Canada 588 Booth Street, Room 108 Ottawa, ON K1A 0Y7 Prepared by: Sophie Costis, Kristin K. Mueller and Jean‐François Blais Centre Eau, Terre et Environnement (ETE) Institut national de la recherche scientifique (INRS) 490, rue de la Couronne, Québec (Québec) G1K 9A9 Alexandre Royer‐Lavallée, Lucie Coudert and Carmen Mihaela Neculita Research Institute on Mines and Environment (RIME) Université du Québec en Abitibi‐Témiscamingue (UQAT) 445, boul. de l’Université, Rouyn‐Noranda (Québec) J9X 5E4 July 2019 © INRS, Centre - Eau Terre Environnement, 2019 Tous droits réservés ISBN : 978-2-89146-926-5 (version électronique) Dépôt légal - Bibliothèque et Archives nationales du Québec, 2019 Dépôt légal - Bibliothèque et Archives Canada, 2019 TABLE OF CONTENTS LIST OF TABLES ............................................................................................................ V LIST OF FIGURES ........................................................................................................... V LIST OF ABBREVIATIONS ............................................................................................ VII 1 INTRODUCTION...................................................................................................... 1 2 PRE‐CONCENTRATION AND POTENTIAL RECOVERY OF REES FROM ACID MINE DRAINAGE (AMD) ......................................................................................................... 3 2.1 PRESENCE OF REES IN AMD ................................................................................................................ 3 2.2 PROCESSES AND MATERIALS FROM AMD TREATMENT AND REE PRE‐CONCENTRATION .................................... 6 2.2.1 (Co‐)precipitation ...................................................................................................................... 7 2.2.2 Sorption .................................................................................................................................... 8 2.3 RECOVERY POTENTIAL OF REES FROM AMD AND TREATMENT SLUDGE/RESIDUE .......................................... 14 2.3.1 Case studies ............................................................................................................................ 14 2.3.2 Ongoing research .................................................................................................................... 16 2.4 CONCLUSION AND RESEARCH NEEDS ..................................................................................................... 16 3 RECOVERY OF REES FROM BAUXITE RESIDUE (BR) ............................................... 19 3.1 CONTEXT ........................................................................................................................................ 19 3.2 HYDROMETALLURGICAL PROCESS ........................................................................................................ 20 3.2.1 Alkaline leaching ..................................................................................................................... 20 3.2.2 Acid leaching ........................................................................................................................... 20 3.2.3 Bioleaching ............................................................................................................................. 21 3.2.4 Ionic leaching .......................................................................................................................... 22 3.2.5 Purification and recovery of REEs ........................................................................................... 22 3.3 PYROMETALLURGICAL PROCESSES ........................................................................................................ 23 3.4 CHALLENGES OF THE RECOVERY OF REES FROM BR ................................................................................ 24 iii 4 RECOVERY OF REES FROM COAL COMBUSTION PRODUCTS (CCPS) ...................... 27 4.1 PHYSICAL SEPARATION PROCESSES ....................................................................................................... 27 4.2 LEACHING PROCESSES ....................................................................................................................... 29 4.2.1 Acid and alkaline leaching ...................................................................................................... 29 4.2.2 Bioleaching ............................................................................................................................. 31 4.2.3 Ionic extraction ....................................................................................................................... 31 4.3 PYROMETALLURGICAL PROCESSES ........................................................................................................ 32 4.4 OTHER METHODS ............................................................................................................................. 33 4.5 CHALLENGES OF RECOVERY REES FROM CCPS ....................................................................................... 34 5 RECOVERY OF REES FROM PHOSPHOGYPSUM ..................................................... 35 5.1 CONTEXT ........................................................................................................................................ 35 5.2 LEACHING OF REES .......................................................................................................................... 37 5.2.1 Acid leaching ........................................................................................................................... 37 5.2.2 Organic leaching ..................................................................................................................... 39 5.2.3 Bioleaching ............................................................................................................................. 39 5.3 RECOVERY METHODS ........................................................................................................................ 40 6 RECOVERY OF REES FROM URANIUM MINING ACTIVITIES ................................... 41 6.1 CANADIAN CONTEXT ......................................................................................................................... 41 6.2 RECOVERY OF REES FROM URANIUM MINING AND MILLING ...................................................................... 42 7 CONCLUSIONS ...................................................................................................... 45 8 REFERENCES ......................................................................................................... 47 iv LIST OF TABLES Table 1. Typical concentrations of REEs in AMD. ..................................................................... 5 Table 2. Performance of AMD neutralization and metal(loid)s precipitation for REE pre‐ concentration from AMD. ......................................................................................... 10 Table 3. Performance of sorption for REE pre‐concentration from AMD. ............................. 12 Table 4. Recent literature on leaching of REE from phosphogypsom. Modified from (Lambert et al., 2018). .............................................................................................................. 38 LIST OF FIGURES Figure 1. Flow diagram of REY (REEs+Y) extraction from fly ash by Wang et al. (2019). ......... 30 Figure 2. Phosphoric acid production flowsheet with REE distribution. Modified from (Wu et al., 2018). .................................................................................................................. 36 Figure 3. Locations of operating, closed and decommissioned uranium mining and milling waste sites in Canada. Modified from (NRCan, 2018a). ........................................... 41 v LIST OF ABBREVIATIONS [Hbet][Tf2N] bis(trifluorométhylsufonyl)imide [Hbet‐STFSI‐PS‐DVP] betainiumsulfonyl (trifluoromethanesulfonylimide) poly(styrene‐co‐ divinylbenzene) [EMIMHSO4] 1‐ethyl‐3‐methylimidazoliumhydrogensulfate AMD Acid mine drainage AC Activated carbon BR Bauxite residue CCPs Coal combustion products CMD Coal mine drainage DAS Dispersed alkaline substrate DOE Department of energy DVB Divinylbenzene EDTA Ethylenediaminetetraacetic acid HDEPH Di‐(2‐ethylhexyl)phosphoric acid HRT Hydraulic retention time ISL In‐situ leaching HREEs Heavy rare earth elements LREEs Light rare earth elements MREEs Middle rare earth elements NASC North American shale composite NMD Neutral mine drainage PG Phosphogypsum REE Rare earth elements REO Rare earth oxides TBP‐TOPO Tributyl phosphate‐trioctylphosphine oxide TENORM Technically enhanced naturally occurring radioactive material TREE Total rare earth elements WEEE Waste electrical and electronic equipment vii 1 INTRODUCTION Rare earth elements (REEs) are of growing interest and their applications cover many fields. In particular, they are essential in the design of emerging technologies such as wind turbines, hybrid cars and mobile phone speakers (EuRare, 2017). Thus their demand in recent years has continued to increase. China, with nearly half of the world's known reserves, dominates REEs production. Indeed, 94 % of REEs production is held by China (Schlinkert & van den Boogaart, 2015). In view of the growing demand and the desire to emancipate themselves from China, many countries, including