Germanium redistribution during weathering of Zn mine wastes: Implications for environmental mobility and recovery of a critical mineral
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- More information: Publisher Index Page (via DOI)
- Data Releases:
- USGS data release - Mineral abundances within bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
- USGS data release - Molecular speciation of Ge within sphalerite, hemimorphite, and quartz from mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
- USGS data release - Geochemical, mineralogical, and molecular scale speciation characterization of mine wastes from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
- USGS data release - Electron microprobe analyses of sphalerite and hemimorphite from mine wastes from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
- USGS data release - Elemental concentrations for bulk and size-fractionated mine waste from the Tar Creek Superfund Site, Tri-State Mining District, Oklahoma, U.S.A.
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Abstract
Germanium (Ge) is a metal used in emerging energy technologies, communications, and defense, and has been deemed critical by the United States due to its essential applications and scarce supply. Germanium is recovered as a byproduct of zinc (Zn) sulfides, and mining and processing of these materials lead to waste that could act both as a source of extractable Ge and a source for exposure to humans and ecosystems. Yet the distribution, speciation, and mineral hosts of Ge in mining-impacted areas are poorly understood. The Tar Creek Superfund Site, a former Zn mining area and Ge producer, is a natural laboratory to understand the environmental behavior and economic implications of Ge in mine wastes. We studied the distribution and behavior of Ge in solid wastes at the Tar Creek Superfund Site using bulk and microanalytical techniques. In wastes at this site we find that Ge has been redistributed from its original host, sphalerite (ZnS), to the fine-grained weathering product hemimorphite (Zn4Si2O7(OH)2·H2O), which impacts germanium's mobility, bioaccessibility, and potential for recovery. We provide chemical and mineralogical evidence of this redistribution, along with an evaluation of the oxidation state and molecular-scale substitution of Ge into sphalerite, hemimorphite, and quartz. Geochemical modeling shows that hemimorphite is more stable than sphalerite in waste piles and provides a stable secondary repository for Ge. However, hemimorphite is fine-grained, and if ingested or inhaled is readily soluble, with the potential to release Ge. Lastly, we discuss other sites internationally where similar behavior may be important. This study shows that weathering can have a significant impact on the distribution, speciation, and mineral hosts of Ge in mine wastes; directly influence mobilization from waste piles and subsequent availability to humans and ecosystems; and dictate metallurgical strategies to target Ge for recovery.
Study Area
| Publication type | Article |
|---|---|
| Publication Subtype | Journal Article |
| Title | Germanium redistribution during weathering of Zn mine wastes: Implications for environmental mobility and recovery of a critical mineral |
| Series title | Applied Geochemistry |
| DOI | 10.1016/j.apgeochem.2022.105341 |
| Volume | 143 |
| Year Published | 2022 |
| Language | English |
| Publisher | Elsevier |
| Contributing office(s) | Eastern Geology and Paleoclimate Science Center, Geology, Energy & Minerals Science Center |
| Description | 105341, 12 p. |
| Country | United States |
| State | Oklahoma |
| Other Geospatial | Tar Creek Superfund Site |
| Google Analytic Metrics | Metrics page |