Process Development to Recover Rare Earth Metals from Selected Primary Ores: A Review

Abstract

Rare earth elements (REEs) have become an integral part of modern-day technology. REEs such
as light rare earth elements (LREEs) are from lanthanum to europium and heavy rare earth
elements (HREEs) from gadolinium to lutetium. Rare earth metals are becoming a significant part
of modern-day technology and material industry because of their applications in various fields
such as hydrogen storage, alloys, batteries, bio-analysis, and nuclear technologies. Due to its
multitudinous devotions in various fields, its demand is increasing day by day. This urge leads
scientists to work tirelessly to discover novel methods and technologies that are beneficial in the
modern era. China has considered a global leader in REE production, and its technological
takeover is due to REE reserves. China has limited the supply of REE to other countries.
Therefore, scientists are trying to discover low-cost and effective ways of its extraction from
primary and secondary sources. Therefore, this is the need of the hour to unearth ores that contain
REE and extract them by using a sustainable approach. Factors affecting leaching efficiency are
the concentration of lixiviant, temperature, contact time, pulp density, and agitation have also been
discussed in detail. This review highlights the leaching mechanism involved in REE extraction
from primary sources. The lixiviant used has been discussed in detail. Prospects of the process
have also been discussed. This tutorial-based review would be really helpful for the researchers.