Rare Earth Elements (REEs) in Complex Ores and Spent Materials: Processing Technologies and Relevance in the Global Energy Transition

Rare earth elements (REEs) as found on the periodic table consist of lanthanides, namely lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, and transition metals yttrium and scandium. In view of the rising global campaign for transition to green economy and energy technologies, there has been a corresponding increase in the relevance of these elements since they are required in the manufacturing of key components in clean energy devices such as wind turbines, solar panels, and electric cars. As a result, the gap between the demand and supply of these critical minerals in the global market has widened in recent years. The supply crisis is partly because REEs often exist in complex primary deposits, which would require sustainable economic and environmentally friendly processing to achieve profitability. This book chapter describes rare earth chemistry, global distribution, their complex ores, possible conventional and environmentally friendly recovery technologies, as well as their relevance in global energy transitions. The authors are fully persuaded that the chapter would be useful to students, teachers, researchers, industry players, and policymakers in the mining and mineral processing industry.