• Resources Recycling
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• v.26 no.4
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• pp.9-18
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• 2017

Recently, the amount of electronic scrap is rapidly increasing due to the rapid growth of the electronics industry. Among the components of electronic scrap, the printed circuit board(PCB) is an important recycling target which includes common metals, precious metals, and rare metals such as gold, silver, copper, tin, nickel and so on. In Korea, however, PCB recycling technologies are mainly commercialized by some major companies, and other process quantities are not accurately counted. According to present situation, several urban mining companies, research institutes, and universities are conducting research on recovery of valuable metals from PCBs and/or reusing them as raw materials that is different from existing commercialization process developed by major companies. In this study, we analyzed not only current status of collection/disposal process and recycling of waste PCBs in Korea but also the trend of recycling technologies in order to help resource circulation from waste PCBs become more active.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.2
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• pp.24-35
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• 2019

In this study, a hotspot analysis was conducted to suggest a new method for interpreting soil heavy-metal contamination data of abandoned metal mines according to statistical significance level. The spatial autocorrelation of the data was analyzed using the Getis-Ord $Gi{\ast}$ statistic in order to check whether soil heavy metal contamination data showing abnormal values appeared concentrated or dispersed in a specific space. As a result, the statistically significant data showing abnormal values in the mine area could be classified as follows: (1) the contamination degree and the hotspot value (z-score) were both high, (2) the contamination degree was high but the z-score was low, (3) the contamination degree was low but the z-score was high and (4) the contamination degree and the z-score were both low. The proposed method can be used to interpret the soil heavy metal contamination data according to the statistical significance level and to support a rational decision for soil contamination management in abandoned mines.

• Journal of Soil and Groundwater Environment
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• v.10 no.6
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• pp.75-80
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• 2005

Several metalliferous including Guedo mine, Manjung mine and Joil mine located at the upper watershed of Namhan river, were abandoned or closed since 1988 due to the mining industry promotion policy and thus disposed an enormous amount of mining wastes without a proper treatment facilities, resulting in soil pollution. In this research, total and fractional concentrations of heavy metals in mining wastes were analyzed and accordingly the degree of soil pollutions in the abandoned mine area were quantitatively assessed employing the several pollution indices. The mining waste samples from Guedo mine, Manjung mine and Joil mine recently abandoned were collected for the evaluation of the potential of water pollution by mining activities. Index of geoaccumulation fractional composition and removal efficiency of some heavy metals by different concentration of HCl treatment were analyzed. Index of geoaccumulation of Cd, Pb, Zn, Cu, Ni and Cr are 6, $4\~6,\;0\~6,\;4\~5$, 2 and 0 respectively. The index of geoaccumulation of Cd, Pb, Zn and Cu reveals the mining wastes has high pollution potential in the area. According to sequential extraction of metals in the mine wastes organic fraction of Cu, reducible fraction of Pb, residual fraction of Ni and Zn were the most abundant fraction of heavy metals in mining wastes.

• Economic and Environmental Geology
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• v.37 no.3
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• pp.311-324
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• 2004

We investigated the contamination and behavior of heavy metals in stream sediments within the watershed of Juam Reservoir. Many abandoned mines within the reservoir can act as a potential contaminant source for water quality. Heavy metal concentrations (Cr, Cu, Ni, Pb and Zn) in stream sediments from watershed are very low, indicating that content of heavy metals in the sediments probably do not affect the water quality in Juam Reservoir. However Pb concentration in the stream sediments increases downward streams, suggesting the possible diffusion of Pb contamination. According to the leaching ratio for stream sediments at a strong acidic condition in the abandoned mine areas, the relative mobility for metals decreases in the order of Pb＞Zn=Cu＞Ni＞Cr, indicating that Pb can have a bad effect upon the water quality in Jum Reservoir. Moreover, if contaminated sediment is placed in the bottom of reservoir (i.e., reducing condition), the relative mobility of Pb is the highest, indicating that Pb in the bottom sediments can be leached to water at interface between water and sediment with changing in physicochemical conditions.

• The Journal of Engineering Geology
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• v.13 no.1
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• pp.29-50
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• 2003

Physicochemical Properties of acid mine water of the Chonam-ri Creek and the Sagok-ri Creek in the Kwangyang Au-Ag mine area were determined using geochemical approaches. Metal contamination (Cd, Cu, Pb, Zn) is more serious in the Chonam-ri Creek than in the Sagok-ri Creek. However, the contents of Al and Fe is higher in the Sagok-ri Creek. Such differences between the two creeks probably reflect the abundance and composition of ore minerals. The attenuation processes for acid mine water in both creeks were investigated. In the Chonam-ri Creek, a small retention pond which contains limestone plays an important role in the removal of heavy metals by adsorption or coprecipitation due to increase of pH. The capacity of metal scavenging in this pond depends on the seasonal variation of inflow volume. Reddish yellow precipitates sampled in the Chonam-ri Creek were analyzed by XRD, SEM-EDS, EPMA, and chemical decomposition. The precipitates mainly consist of goethite and are also enriched in Al, Mn, Cu and Zn. This inditates that precipitation of goethite is important for scavenging those trace elements, possibly due to adsorption or coprecipitation. In the Sagok-ri Creek, on the other hand, hydrologic mixing of uncontaminated tributaries results in removal of heavy metals with iron hydroxides precipitation due to the pH increase. The mechanisms proposed for metal attenuation at the confluence between contaminated mine water and uncontaminated tributary water are also explained by the property-property plots.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.330-333
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• 2004

국내 폐금속광산 일대에서 비소 및 중금속의 발암 및 비발암 위해성을 근거로 복원 기준치를 설정하였다. 폐금속광산일대의 주요한 노출 경로는 부지내 폐광석과 광미로부터 직접적인 오염물 흡입과 지하수를 통한 부지내 및 외 섭취의 경로로 구분된다. 지하수의 오염원은 폐광석과 광미 침출로부터의 오염과 갱구 유출로부터의 오염 및 지질매체 자체에 의한 오염이 설정되었다. 높은 오염 수준에 대해서 높은 오염성분감소비와 폐광산일대의 다양한 배경농도로부터 복원기준치를 설정 했을때, 토양 및 지하수의 복원기준치는 비소 위해도의 영향이 매우 큰 것으로 평가되었다. 비소의 높은 독성은 복원 기준치를 매우 낮게 형성했고, 위해도가 낮은 아연과 카드늄은 높게 설정되었다. 궁극적으로 오염성분 감소비에 따른 복원기준치 설정은 오염성분의 노출 경로 차단이 복원 목표치를 현실화시킬 수 있음을 보여주었다.

• Journal of the Korean Society of Mineral and Energy Resources Engineers
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• v.55 no.6
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• pp.553-563
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• 2018

In this study, the location conditions and optimal technologies required for creating urban municipalities that can utilize the space in an abandoned mine area, where there is no infrastructure related to recycling wastes and valuable metals, are investigated. The urban mining industry deals with mineral resources through the processing of high value-added industrial by-products and wastes, and it is a useful linkage industry for the development of mineral resources and prevention of mining hazards. Urban mining technologies targeted at the abandoned mine area constitute screening, extraction, and smelting for recycling waste products. By analyzing the technologies available, an industrial network can be developed for recycling waste batteries and catalysts, which are promising raw materials. It is also important to establish an appropriate location for related industries that can generate value-added resources, rather than the resource supply and demand conditions seen in general urban mines. In order to overcome the accessibility and infrastructure limitations, the economic foundation of the abandoned mine area should consider the linkage of raw material supply, key technologies for recycling useful mineral resources that are derived from urban mines, spatial and site conditions, and industrial characteristics.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.9-12
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• 2005

각기 다른 경로로 카드뮴에 오염된 두 토양에서 카드뮴을 중성인 물과 황산 수용액으로 용출하여 보았다. 토양은 자연에서 오랫동안 오염된 금속 폐 광산 토양과 한편으로는 오염되지 않은 토양을 인공적으로 오염시킨 것 두 가지를 재료로 사용하였다. 실험결과, 높은 카드뮴 농도에도 불구하고 자연오염 토양의 경우 추출용매가 물인 경우에는 카드뮴이 거의 용출되지 않았고 산 용액에서는 상대적으로 낮은 농도의 카드뮴이 꾸준히 용출되었다. 이에 반하여 인공오염토양의 경우 카드뮴의 용출량이 많아, 현실적으로 공장부지 등지에서 급격히 오염된 토양에는 산성비가 내릴 경우 카드뮴이 지하수를 오염시킬 위험성이 금속 폐광산등 자연적으로 오염된 토양에서보다 상대적으로 더 큰 것으로 나타났다. 특히 중성인 물에서도 인공오염토양 내 카드뮴의 초기 용출량이 크게 나타났는데, 이것은 공단부지 등에서 상대적으로 토양의 카드뮴 오염이 빠르게 진행된 지역의 지하수 등이 카드뮴 오염에 상대적으로 크게 노출되어 있음을 의미한다.

• Journal of Soil and Groundwater Environment
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• v.10 no.3
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• pp.16-23
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• 2005

In order to remediate acid mine drainage (AMD) from the Jeongam coal mine, steel mill slag, cow manure and limestone were used. As a result of batch test, the proper amounts for treating 1 L of acid mine water from the mine were determined as 15 g of steel mill slag, 15 g of cow manure and 500 g of limestone. After feasibility test, remediation system was arranged in the order of steel mill slag tank combination of cow manure and limestone, precipitation tank and oxidation tank. During 54 days' operations, the pH values of the treated waters increased from 3.0 to 8.3 and 61 % of sulfate concentration in an initial water was decreased. In addition, the removal efficiencies for metals in the water were nearly 99.9% for Al, Fe, Zn and 92.6% for Mn. Thus, the combination of steel mill slag, cow manure and limestone can be used as neutralization 때d metal removal for acid mine drainage.

• Economic and Environmental Geology
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• v.36 no.2
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• pp.111-121
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• 2003

The objective of this study is to investigate the physical and chemical properties for environmental assessment of water system affected by acid mine drainage (AMD) from coal mining activities in the Youngwol, Jungseon and Pyungchang areas in Korea. During November 2000 to July 2002, 6 times of water samples were collected season-ally from acid mine drainage and nearby streams at 13 coal mines in the study area. The physical and chemical properties including pH, Eh, TDS, salinity, bicarbonates and DO were measured in the field. Eighteen cations includ-ing Al, Ca, Fe, Mg, Mn and Zn, and 6 anions including nitrates and sulfates were also analyzed by ICP-AES and If, respectively. Acid water from the Jungam coal mine has typical characteristics of AMD with very low pH(3∼4) and high TDS(1,000∼5,000 mg/1). Relatively high concentrations(mg/kg) of heavy meals, especially for Al(380), Fe(80), Mn(44) and Zn(8), were found in water samples from the Jungam coal mine area. Water samples from the Seojin, Sebang and Sungjin coal mines also contained over 50 mg/l of Al, >100 mg/1 of Fe and )10 mg/1 of Mn. In addition to anioins, over 1,000 mg/l of sulfate was found in several water samples. Seasonally, the concentrations of metals and sulfates varied; wet season samples were relatively higher in metals and sulfates than dry season samples. It is needed to establish the proper remediation and environmental monitoring of the AMD continuously.