Modeling Liquid–Liquid Extraction for Critical Elements Separations: An Overview

Liquid–liquid extraction technology exploits the relative ability of solutes to distribute between immiscible liquid phases in contact to recover target components from primary feed mixtures. Theoretical strategies for representing these liquid–liquid extraction systems model aspects of the problem relevant to phase equilibria, flowsheet design, and process optimization. This chapter reviews such strategies for modeling liquid–liquid extraction systems, covering topics ranging from theoretical principles to current and emerging implementation techniques. Although not intended to be a comprehensive treatment of the subject, this chapter provides a systematic, high-level overview of modeling strategies pertinent to each aspect of the liquid–liquid extraction problem. While primarily intended for critical materials recovery, the high-level view adopted makes the chapter content necessarily broad and therefore relevant to other liquid–liquid extraction applications.