G. Moldoveanu, V. Papangelakis
2013
Citations
2
Influential Citations
157
Citations
Quality indicators
Journal
Hydrometallurgy
Abstract
Abstract The present study investigates the use of ammonium sulfate as a lixiviant in the recovery of rare earth elements (REE) from clays. Rare earth ions are physically adsorbed on clay minerals, with concentrations ranging from 0.05 to 0.5 wt.%. It was previously shown that they could be easily recovered via an ion exchange mechanism during leaching with inorganic monovalent salt solutions (such as ammonium sulfate). A standardized desorption procedure was established to systematically investigate the influence of leaching conditions such as lixiviant concentration, temperature, pH and agitation rate on desorption kinetics and REE extraction levels. It was determined that the optimum leaching conditions, leading to 80–90% total REE extraction, required pH values in the range 3–4 and moderate temperatures (