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ORCID
https://orcid.org/0000-0002-4346-437X
Access Type
Open Access Thesis
Document Type
thesis
Degree Program
Geosciences
Degree Type
Master of Science (M.S.)
Year Degree Awarded
2021
Month Degree Awarded
February
Abstract
Because Ga shares many physicochemical properties with Al and Fe, Ga may be able to incorporate into Al and Fe oxy-hydroxides. Understanding how Ga incorporates into these oxy-hydroxides may be crucial for finding Ga-rich bauxite deposits. In order to find the difference in Ga inclusion rates into oxy-hydroxides, as well as understand the mechanisms for this Ga inclusion, Al and Fe oxy-hydroxides were synthesized in the lab with Ga additions of 2 mol % Ga and 20 mol % Ga for a low-Ga and high-Ga treatment, respectively, along with a no added Ga control. X-Ray diffraction analyses confirmed the formation of bayerite (α-Al(OH)3) and goethite (FeOOH) after 100 days (goethite long synthesis [LS]). A second batch of goethite was synthesized in the lab and aged for 60 hours (goethite short synthesis [SS]). Results showed the highest Ga inclusion rates in goethite LS minerals at 0.89 mol % / mol % Ga, then 0.17 mol % / mol % Ga in goethite SS, and 0.50 mol % / mol % Ga in bayerite. Scanning electron microscopy and electron microprobe analyses determined co-precipitation of Ga was the dominant Ga incorporation mechanism in bayerite over isomorphic substitution, where needle-like mineral assemblages began to form in the high-Ga treatments. Isomorphic substitution vii was dominant in both goethite batches. Additionally, Ga mol % in the high-Ga goethite LS and goethite SS minerals revealed a temporal aspect to Ga inclusion in goethite. Goethite LS high-Ga treatment minerals had Ga mol % of 16.8 ± 0.23 % compared to 3.34 ± 0.03 % for high-Ga treatment goethite SS minerals. This study highlights an advance in knowledge of Ga incorporation mechanisms into Al and Fe oxy-hydroxides and provides a basis for future studies to expand on these efforts.
DOI
https://doi.org/10.7275/20889212
First Advisor
Justin B. Richardson
Recommended Citation
Palmer, Corey A., "Investigating Gallium Inclusion in Aluminum and Iron Oxyhydroxides" (2021). Masters Theses. 1019.
https://doi.org/10.7275/20889212
https://scholarworks.umass.edu/masters_theses_2/1019