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dc.contributor.authorSachan, Ankur
dc.date.accessioned2019-07-06T21:15:44Z
dc.date.available2019-07-06T21:15:44Z
dc.date.issued2019-05
dc.identifier.urihttp://hdl.handle.net/11122/10536
dc.descriptionThesis (M.S.) University of Alaska Fairbanks, 2019en_US
dc.description.abstractRare earth elements (REEs) are a group of seventeen elements that include scandium, yttrium, and fifteen of the lanthanide series elements, which are used in a variety of consumer goods and for defense purposes. Acquiring a domestic profitable source of REEs is a critical national need as most of the global supply comes from one country, China. To counter this problem, the US is actively looking at alternative sources of REEs by implementing unconventional methods of extraction. Coal is one of the alternative sources of REEs. Alaskan coal from Wishbone Hill and Healy are known to contain REEs up to 286 ppm and 524 ppm, respectively, while having concentrations as high as 950 ppm on ash basis in some density fractions. Microbial leaching or bioleaching is a novel method that can be used for extraction of REEs from coal as microbes are known to affect earth's surface over geologic time by playing critical roles in weathering of minerals. A certain species of bacteria, Shewanella oneidensis MR-1, was used to separate the REEs from Wishbone Hill and Healy coal samples. The experiments were performed for various density fractions of both coals by varying solids percentage, temperature, size of coal, and bacterial concentration, and recovery of REEs for these conditions was recorded. Highest individual recovery of neodymium, 75.3%, was obtained for Wishbone Hill 1.3 floats, while a maximum of 98.4% total REE recovery was obtained for Healy 1.3 sinks. Healy coal has the higher total recovery of REEs in comparison to Wishbone Hill coal. Bioleaching process was also compared to the acid leaching process. Healy coal responded better to bioleaching than the acid leaching process. The Wishbone Hill coal had comparable recoveries of bioleaching with acid leaching, although they were always less than acid leaching.en_US
dc.description.sponsorshipUniversity of Alaska Fairbanks: Department of Mining and Geological Engineering and Department of Laboren_US
dc.language.isoen_USen_US
dc.subjectrare earth metalsen_US
dc.subjectrare earthsen_US
dc.subjectrare earth metal compoundsen_US
dc.subjectcoal minesen_US
dc.subjectminingen_US
dc.subjectAlaskaen_US
dc.titleEnhanced bioweathering of coal for rare earth element extraction and concentrationen_US
dc.typeThesisen_US
dc.type.degreemsen_US
dc.identifier.departmentDepartment of Mining and Geological Engineeringen_US
dc.contributor.chairGhosh, Tathagata
dc.contributor.chairBriggs, Brandon
dc.contributor.committeeGanguli, Rajive
dc.contributor.committeeAggarwal, Srijan
refterms.dateFOA2020-03-06T03:00:56Z


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