Characterization of Residual Mineral Content of Bauxite Stockpiles in Saline County, Arkansas: An XRD Analysis Approach

<p>The Saline Mining District of central Arkansas once led U.S. alumina production and hosts extensive bauxite and nepheline syenite deposits. With the depletion of highgrade ore, renewed interest in bauxite stockpiles has focused on critical mineral potential. Previous X-ray Fluorescence studies have identified critical elements in significant concentrations, including uranium (U), thorium (Th), gallium (Ga), molybdenum (Mo), and lanthanides (Ln). This study examines five stockpiles (SP1, Clay, SP2, SP3, and SP4) in Section 20 of the Aluminum Company of America (ALCOA) Saline County bauxite mine, using Xray Diffraction (XRD) on 25 samples to characterize mineral phases and compare them with preliminary X-ray fluorescence (XRF) data. Gibbsite and kaolinite dominate the mineralogy, with gibbsite showing strong positive correlations with zirconium (r = 0.76) and niobium (r = 0.72). Siderite, a minor mineral phase, appears associated with niobium, zirconium, and titanium, suggesting trace metal affinity. A strong inverse relationship between gibbsite and kaolinite (r = -0.96) indicates differing formation pathways. Anatase and rutile show weak correlation (r = 0.16), implying variable titanium mobility. These findings highlight geochemical heterogeneity and may guide future critical mineral exploration, provided technological and economic conditions support resource development.</p>

Name thesis:degree_name

Master of Science - Geology

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Geology

Year dc:date.available

2025

Author dc:creator

• Sezibera, Andrew Kaze

Contributors dc:contributor

• Dr. Melinda Faulkner
• Dr. Julie Bloxson
• Dr. Alyx Frantzen

• XRD
• Bauxite
• Arkansas
• Geochemistry
• Geology

Repository record dc:identifier

https://scholarworks.sfasu.edu/etds/595

OAI identifier oai:identifier

oai:scholarworks.sfasu.edu:etds-1660