Rare Earths in Phosphate: Characterization and Extraction

Abstract

Much of this chapter is based on results from a multi-year research project supported by the Critical Materials Innovation (CMI) Hub (formerly Critical Materials Institute) funded by the U.S. Department of Energy, Advanced Materials & Manufacturing Technologies Office. The Florida Industrial and Phosphate Research (FIPR) Institute, Florida Polytechnic University also provided substantial funding. Under the CMI project, FIPR Institute was engaged in three major activities: (1) chemical and mineralogical characterization of rare earth elements (REEs) in different phosphate-processing streams, (2) concentration of uranium- and REE-containing materials from the various processing streams, and (3) extraction of REEs and uranium from the concentrated materials. This chapter covers the main findings of those three efforts, and is divided into four parts. Part I covers chemical analysis and basic properties of different samples. Part II is a detailed process-mineralogy study of the amine flotation tails. Part III focuses on isolation and characterization of rare earth mineral particles in three samples using dual energy (DE) rapid scan radiography and high-resolution X-ray microtomography (HRXMT). Part IV presents process development work on the concentration of REE-containing materials and extraction of REEs.