• Journal of the Mineralogical Society of Korea
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• v.31 no.3
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• pp.173-182
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• 2018

The precipitation and phase transformation processes of iron minerals in acid mine drainage have a great influence on the behavior of trace elements in drainage. However, it is not easy to accurately trace these processes in natural environments, and therefore, most studies have carried out in the laboratory to obtain the information on the precipitation and transformation of those minerals. In this study, the precipitation of minerals and the changes of trace elements in drainage water were investigated at different pH values in actual acid mine drainage collected from the Dalsung mine. The amount of some precipitated minerals was not enough for the mineral identification. However, from the minerals identified, amorphous minerals were formed first, and then goethite was precipitated probably from schwertmannite. When the pH of the sample was high (10), amorphous phases of minerals were still observed at even high pH (pH 10). With increasing time, the pH values decreased by precipitation and transformation of minerals. All the elements showed low concentrations at high pH (8, 10), which might be due to the precipitation of minerals at high pH and the effect of surface charge, and the concentrations of elements gradually increased with time. In the case of sulfur, it also increased in water due to the transformation of schwertmannite to goethite.

• Journal of Soil and Groundwater Environment
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• v.8 no.2
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• pp.9-18
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• 2003

Sampling of waters from each stage of treatment system (Successive Alkalinity Producing System; SAPS), tailings seepage, and spring near the Hanchang coal mine of Kangwon Province were carried out seasonally and analyzed to evaluate the source and possible path of groundwater contamination by acid mine drainage (AM). Sulfur isotope compositions were measured to identify the origin of groundwater contaminations and the sulfate reduction processes in the SAPS. Low pH and high metal concentration of spring water indicates possibility of the groundwater contamination by AMD. Removal efficiency of acidity of the SAPS was 18.17 g/$\textrm{m}^2$/day on an average and the metal removal efficiency was almost 100%, which was higher than those of other treatment systems. However, no appreciable decrease of sulfur content and almost similar sulfur isotope compositions of water from each stage of the treatment system may suggest incomplete or very poor sulfate reduction by sulfate reducing bacteria. Chemical and sulfur isotope compositions showed that spring water was contaminated by seepage from mine tailings. And seepage of stonewall, a part of treatment system was affected by both tailings seepage and mine adit drainage. In this study site, the treatment system was constructed for the only AMD from mine adit not for tailings seepages, which resulted in the groundwater contamination from tailing seepages. Similar situation is expected in other abandoned coal mine areas.

• Journal of Soil and Groundwater Environment
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• v.15 no.6
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• pp.29-36
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• 2010

Several mines including Namil, Solim and Jungbong which are located in the Gyeonggi and Kangwon province have been abandoned and closed since 1980 due to "The promotion policy of mining industry". An enormous amount of mining wastes was disposed without proper treatment, which caused soil pollution in tailing dam and ore-dressing plant areas. However, any quantitative assessment was not performed about soil and water pollution by transporting mining wastes such as acid mine drainage, mine tailing, and rocky waste. In this research, heavy metals in mining wastes were analyzed according to leaching method which used 0.1 N HCl and total solution method which used Aqua-regia to recognize the ecological effect of distance from hot spot. We sampled tailings, rocky wastes and soils around the abandoned mine. Chemical and physical parameters such as pH, electrical conductivity (EC), total organic carbon (TOC), soil texture and heavy metal concentration were analyzed. The range of soil's pH is between 4.3 and 6.4 in the tailing dam and oredressing plant area due to mining activity. Total concentrations of As, Cu, and Pb in soil near ore dressing plant area are 250.9, 249.3 and 117.2 mg/kg respectively, which are higher than any other ones near tailing dam area. Arsenic concentration in tailing dams is 31.0 mg/kg, which is also considered as heavily polluted condition comparing with the remediation required level(RRL) in "Soil environment conservation Act".

• Economic and Environmental Geology
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• v.42 no.3
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• pp.207-216
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• 2009

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.

• Economic and Environmental Geology
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• v.43 no.1
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• pp.21-31
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• 2010

Mine and leachate waters were collected from the Okdong mine for study on reaction with oxidizing agents such as NaOCl and $H_2O_2$. The pH and EC of the mine and leachate waters are 5.77, 831 uS/cm, and 6.38, 1920 uS/cm, respectively. The concentrations of Mg, Mn, and Zn are 23.25 mg/l, 14.90 mg/l, and 22.99 mg/l for the mine water and 98.75 mg/l, 3.38 mg/l, and 6.16 mg/l for the leachate water. The concentrations of Mg, Mn and Zn decreased after the reaction with the oxidizing agents and mine water. The concentrations of Mg, Mn and Zn rapidly decreased when oxidizing agents increased. The saturation indices that were computed by visual MINTEQ for initial mine and leachate water were undersaturated with Mg, Zn and Mn compounds. The precipitates after the reaction with the oxidizing agents are composed mainly of mangano-calcite[(Mn, Ca)$CO_3$] with small amount of calcite-magnesian and calcite.

• Journal of Environmental Impact Assessment
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• v.18 no.4
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• pp.209-218
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• 2009

The purpose of this study was to accumulation of the heavy metals by riparian vegetation throughout analysis of the heavy metal concentration in riparian vegetation, water, and sediment near mine drainage. According to analyzing concentration of the heavy metals in riparian vegetation, water, and sediment the heavy metal was indicated at the leaf significantly. Compared with the concentration of sediment soil, the maximum concentration of the As, Cd, CN, Pb, Zn was higher 2.6, 2.6, 25, non-detect, and 15 times in leaf. Also those concentration have 9.6, 16.6, 25, 1.6, and 25 times in root. As the results, the author can know the sediment has a very relative to vegetation in mine drainage. because, the increasing of concentration of heavy metal in sediment gives the more accumulative concentration of heavy metal in vegetation. Compared with the concentration of conta minated site and non-contaminated site. As, Cd, CN, Pb, Zn the maximum concentration in sediment soil was higher 5.7, 258.1, 10.9, 370.0, and 298.3 times respectively. In case of vegetation, the maximum concentration of the As, Cd, CN, Pb, Zn was higher 5.6, 62.3, 5.0, non-detect, and 30.6 times in leaf. Also those concentration have 8.5, 63.3, 2.6, 60.7, and 62.1 times in root. In this study, the author can surmise that there indicated a lot of adsorption with the heavy metal concentration in contaminated mine drainage.

• Economic and Environmental Geology
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• v.53 no.2
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• pp.133-145
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• 2020

Soil in mine waste-rock fields, and at the pithead, sediments and farmlands around an abandoned mine in the Chungcheong Province of South Korea were investigated to assess the distribution of metallic elements and to understand the scope of the pollution. Reddening was observed from the mine up to a distance of 61 m. Losses of waste rock around the mine were assessed over a section of 1800 ㎥. Yellowish precipitates on the bottom of a stream were identified as ferrihydrite and goethite. For anions, a mean sulfate ion level over 773.6 mg/L was found during August in the river water samples. Mine drainage at the site was shown to have a pH of 4.9 and a sulfate concentration of 1557.8 mg/L during the August rainy season. A possible cause of the metallic element contamination in the mine is waste-rock loss, because mine waste-rock is located on the slope in this area. In conclusion, the total soil area to be treated, based on the amount that exceeded the recommended Korean soil pollution levels, was assessed to be 10,297 ㎡.

• Economic and Environmental Geology
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• v.33 no.5
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• pp.391-404
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• 2000

This study investigated the geochemical characteristics of mine drainage discharged from an abandoned coal mine in the Hwasoon area. Surface water samples were collected from 23 locations along the Hancheon creek. The concentration of Zn and Cu in stream waters was highest at low pH (3.53), whereas the content of TDS and TDI was highest at high pH (7.78) due to the concentration of Ca, $HCO_3$ and $SO_4$. At the upstream site, the Ba, Fe, Mn, Zn, and $SO_4$ contents were relatively high but decreased significantly with the distance from the coal mine. On the contrary, the Na and $NO_3$ contents were low at the upstream site but increased downstream. Yellow precipitate material collected in the Hancheon consisted mainly of iron and LOI. This yellow precipitate was heated from 100 to $900^{\circ}C$ for 1 hour. With increasing temperature, the intensity of hematite peaks were sharply produced in X-ray pattern and the absorption band Fe-O of hematite increased in IR due to dehydration and melting. The yellow to brown precipitate and evaporite materials were collected by a air-dry from the acid mine water at the laboratory. After drying, the concentration of ions in the acid water samples increased progressively in oversaturation with respect to either gypsum, ferrohexahydrite or quenstedetite. The X-ray powder diffraction studies identified that the precipitated and evaporated materials after drying were well crystallized gypsum, ferrohexahydrite and quenstedetite. Diagnostic peaks used for identification of gypsum were the 7.65, 4.28, 3.03, 2.87 and 2.48$\AA$ peaks and those for ferrohexahydrite were the 5.46, 5.12, 4.89, 4.44, 4.05, 3.62, 3.46, 3.40, 3.20, 3.03, 2.94, 2.53, 2.28, 2.07, 1.88 and 1.86${\AA} peaks. The IR spectra with OH-stretching, deformation of $H_2O$and ${SO_4}^{2-}$stretching vibration include the existence of gypsum, ferrohexahydrite and quenstedetite in the precipitated and evaporite materials. In the SEM and EDS analysis for the evaporite material, gypsum with well-crystallized, acicular, and columnar form was distinctly observed.

• The Journal of Engineering Geology
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• v.29 no.2
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• pp.163-183
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• 2019

We investigated acid mine drainage (AMD) of Bongyang abandoned coal mine, Danyang, Chungbuk Province with emphasis on geochemical contaminants in AMD and precipitates using chemical analyses, XRD, SEM, IR, and $^{27}Al$ NMR. Water chemistry changes with pH and oversaturation of chemical species. According to calculation of saturation index, the AMD is saturated with various Fe, Al minerals. Orange or orcher precipitates are composed of schwertmannite and goethite, associated with Leptothrix orchracea bacteria, whereas whitish precipitates are composed mostly of alumimous minerals such as basaluminite with poor crystallinity. The whitish precipitates include trace $Al_{13}$-Tridecamer. It is important to control the precipitation and solubility of aluminous species for ensuring remediation and control for the AMD discharged from the Bongyang abandoned coal mine.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.258-261
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• 2000

Geophysical surveys (electrical resistivity, self-potential, and magnetic methods) and streamwater sample analysis have been carried out at a site of tailings of waste deposits in an abandoned mine, Jangpoong, which is situated in Kowesan-Gun, Chungbuk-Do. The research was aimed at investigating the suitability of the various geophysical methods for detection of AMD (acid mine drainage) paths, and ultimately mapping of preferred AMD flow channels by incorporating the water sample analysis. Electrical resistivity section from the dipole-dipole line represents the low-resistivity zone trending northwest toward the stream nearby. The positions of the resistivity anomalies for AMD channels are well correlated to the ones from the various geophysical surveys. In addition they correspond to the sites of the higher peaks for the pH, EC, heavy metal content for the water sample data.