Seasonal Variations of Water Quality within the Waste Impoundments of Geopung Mine

거풍 폐광산 폐기물 적치장 지하수 및 침출수 수질의 시기별 변화

  • Ahn, Joo-Sung (Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources) ;
  • Yim, Gil-Jae (Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources) ;
  • Cheong, Young-Wook (Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources)
  • 안주성 (한국지질자원연구원 지구환영연구본부) ;
  • 임길재 (한국지질자원연구원 지구환영연구본부) ;
  • 정영욱 (한국지질자원연구원 지구환영연구본부)
  • Published : 2009.06.28

Abstract

In this study, water quality variation in borehole groundwaters and surface leachate waters were investigated on a seasonal sampling and remote monitoring basis within the waste impoundments at the Geopung mine site where previous rehabilitation measures were unsuccessful to prevent acidic drainage. All groundwaters were typical acidic drainage with acidic pH (3.3${\sim}$4.6) and high TDS (338${\sim}$3330 mg/L) values during the dry season, but increases in metal contents (TDS 414${\sim}$4890 mg/L) and decrease of pH (2.7${\sim}$3.6) were observed during the rainy season. Surface leachate waters showed a similar pattern in water quality variation. Surface runoff waters during rain events had acidic pH (3.0${\sim}$3.4) through direct reactions with waste rocks. Good correlations were found between major and trace elements measured in water samples, but no significant seasonal variation in chemical compositions was shown except relative changes in contents. It can be suggested that dissolution of soluble secondary salts caused by flushing of weathered waste rocks and tailings directly influenced the water quality within the waste impoundments. Increases in acid and metal concentrations and their loadings from mine wastes are anticipated in the rainy season. More appropriate cover systems on waste rocks and tailings necessitate consideration of more extreme conditions in the study mine.

폐광지역 광산폐기물 적치장에서 발생하는 산성 침출수 및 이의 영향을 직접적으로 받는 하부 지하수의 수질변화 양상을 자동계측자료 및 시기별 시료 분석으로 평가하였다. 연구지역은 충북 옥천군의 폐광산인 거풍광산이며 한차례 복토작업이 이루어졌으나 산성배수 발생은 지속되었다. 건기의 지하수 시료는 강산성(pH 3.3${\sim}$4.6) 및 높은 총용존고형물질 함량(338${\sim}$3330 mg/L)으로서 전형적인 산성배수의 특성을 보였으며 우기에 중금속 함량 증가(TDS 414${\sim}$4890 mg/L)와 pH 2.7${\sim}$3.6으로 보다 강한 산성을 나타내었다. 지표침출수 시료도 유사한 수질변화양상을 보이며 강우시 지표 유거수는 폐석과의 직접 반응으로 강산성(pH 3.0${\sim}$3.4)을 나타내었다. 시료내 주성분 및 중금속원소들 간의 상관성이 전반적으로 높게 나타났으며 개별 성분들의 건우기 함량 증감양상 외에 전체 시기별 수질조성의 큰 변화는 보이지 않았다. 연구지역 광산폐기물 표면에는 금속 수화황산염 등의 다양한 2차 염류가 풍부하게 생성되어있으며 이들의 강우에 용해되어 침출수 및 하부 지하수의 수질에 직접적으로 영향을 주는 것으로 판단한다. 향후 보다 심각한 기후조건에서도 우수한 효율을 나타낼 수 있는 복토 및 처리기법이 요구된다.

Keywords

References

  1. Cheong, Y.W., Yim, G.J., Ji, S.W., Park, H.Y., Min, D.S. and Park, I.W. (2008) Impact of the rain on the geochemical and hydrogical characteristics within a mine waste impoundment at the Geopung mine, Korea. Journal of the Korean Society for Geosystem Engineering, v.45, p.495-504
  2. Gomes, M.E.P. and Favas, P.J.C. (2006) Mineralogical controls on mine drainage of the abandoned Ervedosa tin mine in north-eastern Portugal. Applied Geochemistry, v.21, p.1322-1334 https://doi.org/10.1016/j.apgeochem.2006.06.007
  3. Hammarstrom, J.M., Seal II, R.R., Meier, A.L. and Kornfeld, J.M. (2005) Secondary sulfate minerals associated with acid drainage in the eastern US: recycling of metals and acidity in surficial environments. Chemical Geology, v.215, p.407-431 https://doi.org/10.1016/j.chemgeo.2004.06.053
  4. Jambor, J.L., Nordstrom, D.K. and Alpers, C.N. (2000). Metal-sulfate salts from sulfide mineral oxidation. In: Alpers, C.N., Jambor, J.L. and Nordstrom, D.K. (Eds.), Sulfate Minerals-Crystallography, Geochemistry, and Environmental Significance, Rev. Mineral. Geochem., v.40, p.303-350
  5. Jerz J.K. and Rimstidt, J.D. (2003) Efflorescent iron sulfate minerals: paragenesis, relative stability, and environmental impact. American Mineralogist, v.88, p.1919-1932 https://doi.org/10.2138/am-2003-11-1235
  6. Jurjovec, J., Ptacek, C.J. and Blowes, D.W. (2002) Acid neutralization mechanism and metal release in mine tailings: A laboratory column experiment. Geochemica et Cosmochimica Acta, v.66, p.1511-1523 https://doi.org/10.1016/S0016-7037(01)00874-2
  7. Keith, D.C., Runnells, D.D., Esposito, K.J., Chermak, J.A., Levy, D.B., Hannula, S.R., Watts, M. and Hall, L. (2001) Geochemical models of the impact of acidic groundwater and evaporative salts on Boulder Creek at Iron Mountain, California. Applied Geochemistry, v.16, p.947-961 https://doi.org/10.1016/S0883-2927(00)00080-9
  8. Kinniburgh, D.G., Jackson, M.L. and Syers, J.K. (1976) Adsorption of alkaline earth, transition and heavy metal cations by hydrous oxide gels of iron and aluminum. Soil Sci. Soc. Am. J., v.40, p.796-800 https://doi.org/10.2136/sssaj1976.03615995004000050047x
  9. MIRECO (2008) Detailed survey report on Geopung mine tailings protection project. Mine Reclamation Corporation Technological Report 2008-8, 87p
  10. Nordstrom, D.K. (2007) Effects of seasonal and climatic change on water quality from acid rock drainage in the western United States. In: Cidu, R. and Frau, F. (Eds), IMWA Symposium 2007: Water in Mining Environments, 27th-31st May 2007, Cagliari, Italy
  11. Smuda J., Dold, B., Frise, K., Morgenstern, P. and Glaesser, W. (2007) Mineralogical and geochemical study of element mobility at the sulfide-rich Excelsior waste rock dump from the polymetallic Zn-Pb-(Ag-Bi-Cu) deposit, Cerro de Pasco, Peru. Journal of Geochemical Exploration, v.92, p.97-110 https://doi.org/10.1016/j.gexplo.2006.08.001
  12. Valente, T.M. and Gomes, C.L (2009) Occurrence, properties and pollution potential of environmental minerals in acid mine drainage. Science of the Total Environment, v.407, p.1135-1152 https://doi.org/10.1016/j.scitotenv.2008.09.050
  13. Webster, R. and Oliver M. (2001) Geostatistics for environmental scientists. John Wiley & Sons, Ltd, Chichester, 271p
  14. Yim, G.J., Ahn, J.S., Cheong, Y.W., Min, D.S. and Baek, H.J. (2009) An evaluation of the infiltration control of a soil cover overlying tailings impoundment. Journal of the Korean Society for Geosystem Engineering, v.46, In print