Skip to main content
U.S. flag

An official website of the United States government

Rare earth elements in sedimentary phosphate deposits: Solution to the global REE crisis?

November 26, 2015

The critical role of rare earth elements (REEs), particularly heavy REEs (HREEs), in high-tech industries has created a surge in demand that is quickly outstripping known global supply and has triggered a worldwide scramble to discover new sources. The chemical analysis of 23 sedimentary phosphate deposits (phosphorites) in the United States demonstrates that they are significantly enriched in REEs. Leaching experiments using dilute H2SO4 and HCl, extracted nearly 100% of their total REE content and show that the extraction of REEs from phosphorites is not subject to the many technological and environmental challenges that vex the exploitation of many identified REE deposits. Our data suggest that phosphate rock currently mined in the United States has the potential to produce a significant proportion of the world's REE demand as a byproduct. Importantly, the size and concentration of HREEs in some unmined phosphorites dwarf the world's richest REE deposits. Secular variation in phosphate REE contents identifies geologic time periods favorable for the formation of currently unrecognized high-REE phosphates. The extraordinary endowment, combined with the ease of REE extraction, indicates that such phosphorites might be considered as a primary source of REEs with the potential to resolve the global REE (particularly for HREE) supply shortage.

Publication Year 2015
Title Rare earth elements in sedimentary phosphate deposits: Solution to the global REE crisis?
DOI 10.1016/
Authors Poul Emsbo, Patrick I. McLaughlin, George N. Breit, Edward A. du Bray, Alan E. Koenig
Publication Type Article
Publication Subtype Journal Article
Series Title Gondwana Research
Index ID 70188814
Record Source USGS Publications Warehouse
USGS Organization Central Mineral and Environmental Resources Science Center