• Journal of Soil and Groundwater Environment
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• v.15 no.6
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• pp.72-80
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• 2010

Possibility of the usage of sludge generated in coal mine drainage treatments as a briquette additive was investigated by the combination of industrial, elemental, and combustion experiments. A series of briquettes having 2% and 6% of sludge were used for the experiments. Compared to the control sample, our results show that all experimental values for the briquettes are very similar. In particular, it is worthy to note that there is no obvious difference in calorific values for the briquettes containing 2% or 6% of sludge. The calorific values are 4,250~4,360 kcal/kg, 4,240~4,250 kcal/kg, 4,180~4,210 kcal/kg, and 4,270~4,360 kcal/kg for the control sample, briquette containing 6% of Hambaek sludge, briquette containing 6% of Hamtae sludge, and briquette containing 2% of Hambaek sludge, respectively. Results of ash fusion temperature show that the temperature is greater than $1,550^{\circ}C$ for the control sample. However, the temperature for the briquettes with 6% of Hambaek sludge and 2% of Hambaek or Hamtae sludge is $1,510^{\circ}C$. For a briquette containing 6% of Hamtae sludge, the temperature of ash fusion is $1,530^{\circ}C$. After combustion, environmental impacts of the briquettes with sludge were tested. Little environmental influence was observed for the combusted briquettes with sludge.

• Journal of Soil and Groundwater Environment
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• v.29 no.1
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• pp.10-17
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• 2024

In Korea, the common remedial process for reclamation of agricultural soils nearby abandoned mines involves chemical soil stabilization followed by covering with clean soil. This study investigated the chemical properties of cover soils and the validity of HCl extraction method in assessing the degree of As and heavy metal stabilization in stabilized soils collected from 14 plots where mine reclamation had been completed. The results revealed there were no major differences in contaminants extraction rate between the stabilized soils and contaminated soils, suggesting HCl extraction procedure is a less feasible method to determine the efficiency of the stabilization. Soil quality indicators including OM, SiO₂, P₂O₅, etc. of the land-covering soils were generally lower than those of stabilized soils that used to be the cultivation layer before the stabilization. Nonetheless, the value of those indicators didn't meet the regulatry limits of agricultural soil. Therefore, future strategy for mine reclamation should concentrate not only on contaminant concentration but also on soil quality parameters for agricultural use of the reclaimed soil.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.6
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• pp.109-125
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• 2017

This study aimed to develop a parcel-unit soil loss estimation tool embedded in Excel worksheet, USLExls, required for the design of contaminated farmland restoration project and to analyze the impact of the project carried out soil-filling work on soil loss. USLE method was adopted for the estimation of average annual soil loss in a parcel unit, and each erosivity factor in the USLE equation was defined through the review of previous studies. USLExls was implemented to allow an engineer to try out different combinations just by selecting one among the popular formulas by each factor at a combo box and to simply update parameters by using look-up tables. This study applied it to the estimation of soil loss before and after soil-filling work at Dong-a project area. The average annual soil loss after the project increased by about 2.4 times than before on average, and about 60 % of 291 parcels shifted to worse classes under the classification criteria proposed by Kwak (2005). Although average farmland steepness was lower thanks to land grading work, the soil loss increased because the inappropriate texture of the cover soil induced the soil erosion factor K to increase from 0.33 before to 0.78 after the soil-filling work. The results showed that the selection of cover soil for soil-filling work should be carefully considered in terms soil loss control and the estimation of change in soil loss should be mandatory in planning a contaminated farmland restoration project.

• Resources Recycling
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• v.22 no.4
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• pp.33-37
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• 2013

A study on the removal of arsenic from gold concentrate was conducted using thermal decomposition method at $700^{\circ}C$ as a function of reaction time. In addition, the arsenic removed from the concentrate was also collected in the bag-filter as a form of AsS. The content of arsenic in the concentrate was dramatically decreased from 12.62 wt/% to 1.40 wt.% for 1 hour and even lower than 1 wt.% after two hours. The removal efficiency of arsenic was finally achieved to be about 95% after 2 hours at a given temperature.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.793-807
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• 2020

The policy for Green New Deal will promote the shift of the application to coal as feedstock from coal as fuel. Coal can be used as fuel for production of hydrogen and as feedstock materials such as synthetic graphite or activated carbon. Hydrogen is obtained from syngas produced through Steam carbon(SC), Water-Gas Shift(WGS), and Carbonation reactions, and these processes should be used in conjunction with CO2 sequestration technology. Anthracite has a potential in terms of cost advantage as a feedstock compared to a petroleum pitch, because Synthetic graphite is prepared by heat treating an anthracite with high rank to a graphitization temperature which is in the range of 2400~2800℃, in the presence of inorganic catalyst such as silicon or iron. From several studies, it has been confirmed that coal-based activated carbon(AC) is manufactured with quality similar to the large specific surface area and much micropore volume of lignin-based AC, can be prepared. Therefore it is expected that lignin-based AC is replaced to coal-based AC.

• Economic and Environmental Geology
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• v.53 no.5
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• pp.517-528
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• 2020

The objectives of this study were to select optimal soil amendments through analysis of heavy metal availability in soil and uptake to Miscanthus sinensis Anderss. for phytostablization in heavy metal contaminated soil of abandoned metal mine. M. sinensis was cultivated for 6 months at contaminated soil with several soil treatments (bottom ash 1 and 2%, fly ash 1 and 2%, waste lime+oyster 1 and 2%, acid mine drainage sludge (AMDS) 10 and 20%, compost 3.4%, and control). The analysis results of heavy metal concentrations in the soil by Mehlich-3 mehthod, growth and heavy metal concentrations of M. sinensis showed that AMDS 20% was more effective than other amendments for phytostablization, and AMDS 10% showed second effectiveness. Waste lime+oyster, bottom ash and fly ash were also improved compared to control. Mobility of some heavy metal was increased by treatments. Therefore, it is necessary of preparatory investigation of soil condition to select soil amendment to apply on-site phytostablization.

• The Journal of Engineering Geology
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• v.22 no.4
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• pp.439-448
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• 2012

The aim of this study is to develop eco-friendly, fundamental technology for vegetative restoration of barren lands using green rehabilitation material, for the stabilization of abandoned mine debris slopes and depository slopes composed of rock fragments. It is expected that such methods would help to improve the negative view of artificial slopes that remain following mining activity, while also contributing to slope stabilization and prevention of the loss of rock fragments and the dispersion of tailings. We tested the tensile strength and tear strength of various materials, including commonly used natural coir material, natural fibers, and synthetic textile materials with enhanced durability. In conclusion, there is the possibility that natural coir can be used as an eco-friendly material in vegetation restoration, while its durability in natural conditions can be improved by controlling the degree of knot convolution and by antibacterial treatment against biodegradation.

• Journal of the Mineralogical Society of Korea
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• v.28 no.4
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• pp.309-323
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• 2015

This study was initiated to propose the method for human risk assessment suitable to metal mine area. Using a variety of exposure parameters extracted from the investigation of abandoned metal mines, the proposed method was applied to assess the risk of As and heavy metal contamination for inhabitants (male and female adults and child) within an abandoned mine area. Based on the results of risk assessment, in addition, target remediation concentrations of each media (soil, groundwater, and surface water) were estimated. The results indicate that total carcinogenic risk (TCR) and hazard index (HI) representing carcinogenic and non-carcinogenic risks, respectively, were calculated to exceed the tolerable levels (1.00E-6 and 1) with regard to two exposure pathways (groundwater and crop intakes) and As. Thus, the human risk of study area was evaluated to be significant. Based on the target risk (TR) for carcinogens, the remediation concentrations of soil were computed to be 6.83~6.85 mg/kg and 18.41~18.46 mg/kg for As and Pb, respectively. In terms of target hazard index (THI) for non-carcinogens, the remediation concentrations of soil were calculated to be 17.38 mg/kg for Cu and 9.13 mg/kg for As.

• Journal of Soil and Groundwater Environment
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• v.17 no.6
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• pp.112-118
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• 2012

Fine suspended solids from mine drainage draw attentions due to their potential adverse influences on the water quality, such as increasing turbidity and degrading aesthetic landscape. Currently, sand filter beds are adapted in some mine drainage treating systems. However, more efficient system is in demand, as the existing sand beds reveal some problems, such as frequent maintenance intervals. Various filtering mediums including fly ash, mine tailing aggregates and the sand were tested for improving the current system, using column experimental set-up. Mine drainage samples were collected from the current treating systems in the abandoned H coal mine. The experiment was run for 7 days. Suspended solids recorded as 100.9 mg/L and the value exceeds the current standard, 30 mg/L. Sand was proved to still be the optimum medium for the fine suspended solids, compared to fly ash and fly ash + sand. Mine tailing aggregates were placed at the exit of the columns, substituting gravels. The tailing aggregates is made by mine tailings and clay. Sand bed filters can also be improved by mixing granular activated carbon, which was found to be economical and efficient in the batch experiment, conducted at the same time.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.920-925
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• 2008

In this presentation, a leaching experiment which is followed the pH changes(pH=4, pH=7) and the mixing rates(1%, 3%, 5%, 7%) was carried out to examine the arsenic reduction effects and the leaching characteristics on arsenic contaminated soil after stabilization treatment in which 5 materials were used as stabilization agencies, i.e. ZVI(zero valent iron), blast furnace slag, steel refining slag, quick lime, and oyster shell meal. Except for blast furnace slag, the arsenic removal rate increased as the mixing rate increases of stabilization agencies. Arsenic leaching concentration was indicated that pH=7 condition is higher than pH=4 condition. This result shows because arsenic immobilization reaction increases as pH decreases, and arsenic adsorption takes place as pH decreases.