Date of Award

Spring 5-4-2024

Degree Type


Degree Name

Master of Science in Materials Science and Engineering (MSMSE)


Materials Science

Committee Chair

Jerome Downey

First Advisor

Teagan Leitzke

Second Advisor

Gary Wyss


The effect of coexisting ions on the selectivity of adsorption onto magnetite nanoparticles (MNPs) for various elements in aqueous solutions was investigated. Surrogate solutions of varying concentrations of rare earth elements (REEs), heavy metals, and gangue elements (low commercial value elements or metals) were mixed with MNPs. Selectivity experiments were performed on surrogate samples based on the composition of a REE ore concentrate and a leach liquor from the chlorinated products of the roasted REE ore concentrate. Adsorption efficiency of magnetite was determined by measuring ion concentration in a sample using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Magnetite is selective towards Cr(III) over some of the REEs and metals; this behavior can be controlled by adjusting the pH and MNP dosage. Rare earth experiments show that Sc(III) is selective over other REEs at a pH of 5.3. The REE ore sample and surrogate experiments reveal that magnetite will preferentially adsorb iron over REEs depending on the pH; where iron adsorption efficiency was significantly higher than the REEs at a pH of 2.5 and 4.5. By varying the MNP concentration, it appears plausible that a multi-stage extraction process could use the selectivity trends determined by this study to effectively target extraction of chromium, scandium, and iron.