Research Chemist
Geology, Energy & Minerals Science Center
Email:
shayes@usgs.gov
Office Phone:
703-648-6461
Fax:
703-648-6252
ORCID:
0000-0001-5887-6492
Location
John W Powell FB
12201 Sunrise Valley Drive
Reston
, VA
20192-0002
US
Supervisor:
Jane M Hammarstrom
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Germanium (Ge) is an increasingly important element used in critical technologies for communication, defense, and computing. However, Ge is scarce, and there is no United States (U.S.) primary production. Additionally, the environmental behavior of Ge is poorly understood. Germanium does not generally form its own minerals, but is instead recovered as a byproduct of zinc mining or of coal fly ash. It has been deemed critical by the U.S. and globally, and investigations of its geologic concentration, environmental fate and transport, and potential for recovery are crucial for maintaining a sustainable supply. A relevant study site to explore questions of environmental behavior and the potential to recover...
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This dataset contains X-ray diffraction (XRD) results for coal samples from the Usibelli Coal Mine and fly ash samples from the Atkinson Heat and Power Plant in Fairbanks, AK. Additionally, X-ray diffraction results from the solid phase residuals of leaching experiments with the same fly ash are reported. The leaching experiments were performed with either 18 mgea-ohm or simulated rainwater for up to 90 days and XRD was performed on solid phase residuals from sacrifical timepoints (1 hours, 2 days, 7 days, 14 days, 28 days, and 90 days).
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Germanium (Ge) is an element deemed critical globally, and used in electronics, communication, and defense applications. The supply of Ge is limited and as demand for it increases, its criticality increases. Germanium is exclusively recovered as a byproduct of either coal mining or zinc (Zn) mining, and the main mineral hosting Ge in Zn deposits is sphalerite (ZnS). However, the mechanisms of Ge enrichment in sphalerite during mineral deposit formation are poorly understood. Therefore, investigations on the mechanisms controlling geologic enrichment of Ge in ores is crucial for maintaining a sustainable supply. For this study, we used a combination of techniques including optical and electron microscopy, synchrotron-based...
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This data release contains the bulk chemistry and x-ray diffraction results of unreacted Alaskan stoker-boiler fly ash. X-ray diffraction results from the solid phase residuals of leaching experiments with the same fly ash are reported. The leaching experiments were performed with either 18 mega-ohm or simulated rainwater for up to 90 days and XRD was performed on solid phase residuals from sacrifical timepoints (1 hours, 2 days, 7 days, 14 days, 28 days, and 90 days).
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Electron microprobe analyses of sphalerite (ZnS) and hemimorphite (Zn4Si2O7(OH)2·H2O) from sampled historical waste piles were conducted with a specific focus on germanium (Ge). In mine wastes at the Tar Creek Superfund Site, Oklahoma, USA, Ge is associated with ZnS (sphalerite) as expected, but weathering in the waste piles has led to a significant amount of Ge being incorporated into a zinc-silicate, hemimorphite. Data and methods reported are part of a research study published here: White, S.J.O., Piatak, N.M., McAleer, R.J., Hayes. S.M., Seal, R.R. II, Schaider, L.A., Shine, J.P. Germanium redistribution during weathering of Zn mine wastes: implications for environmental mobility and recovery of a critical...
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