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| Titel |
Inhibition of Sulfide Mineral Oxidation by Surface Coating Agents: Batch |
| VerfasserIn |
J. Choi, M. K. Ji, H. S. Yun, Y. T. Park, E. D. Gee, W. R. Lee, B.-H. Jeon |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250064803
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| Zusammenfassung |
| Mining activities and mineral industries have impacted on rapid oxidation of sulfide minerals
such as pyrite (FeS2) which leads to Acid Mine Drainage (AMD) formation. Some of the
abandoned mines discharge polluted water without proper environmental remediation
treatments, largely because of financial constraints in treating AMD. Magnitude of the
problem is considerable, especially in countries with a long history of mining. As metal
sulfides become oxidized during mining activities, the aqueous environment becomes acid
and rich in many metals, including iron, lead, mercury, arsenic and many others. The toxic
heavy metals are responsible for the environmental deterioration of stream, groundwater and
soils. Several strategies to remediate AMD contaminated sites have been proposed. Among
the source inhibition and prevention technologies, microencapsulation (coating) has been
considered as a promising technology. The encapsulation is based on inhibition of O2
diffusion by surface coating agent and is expected to control the oxidation of pyrite for a long
time.
Potential of several surface coating agents for preventing oxidation of metal sulfide minerals
from both Young-Dong coal mine and Il-Gwang gold mine were examined by conducting
batch experiments and field tests. Powdered pyrite as a standard sulfide mineral and rock
samples from two mine outcrops were mixed with six coating agents (KH2PO4, MgO and
KMnO4 as chemical agents, and apatite, cement and manganite as mineral agents) and
incubated with oxidizing agents (H2O2 or NaClO). Batch experiments with Young-Dong coal
mine samples showed least SO42- production in presence of KMnO4 (16% sulfate production
compared to no surface coating agents) or cement (4%) within 8 days. In the case of
Il-Gwang mine samples, least SO42- production was observed in presence of KH2PO4
(8%) or cement (2%) within 8 days. Field-scale pilot tests at Il-Gwang site also
showed that addition of KH2PO4 decreased sulfate production from 200 to 13 mg
L-1 and reduced Cu and Mn from 8 and 3 mg L-1 to below the detection limits,
respectively. The experimental results suggested that the amendment of surface coating
agents can be a promising alternative for inhibition of sulfide oxidation at AMD
sites. |
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