• Journal of the Mineralogical Society of Korea
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• v.30 no.1
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• pp.1-9
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• 2017

This study investigated the effectiveness of Unmanned Aerial Vehicle (UAV) and 3D modeling on mine reclamation monitoring. The high spatial resolution of 3.8 cm ortho-mosaic image and Digital Elevation Model (DEM) are constructed based on UAV air survey. The ortho-mosaic image effectively shows mine reclamation activities and recognize objects and topological changes in the image. The comparative analysis of 3D models between UAV based DEM and report based DEM reveals that total amount of $268,672m^3$ additional dumping of contaminated soil is equivalent to 710,000 ton. It concludes that a UAV based survey enables high accuracy spatial information extraction for mine reclamation activities with high efficiency. It is expected that UAV survey will be very effectively used for preliminary data acquisition and project monitoring for mine reclamation activities.

• Resources Recycling
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• v.27 no.6
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• pp.11-22
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• 2018

Magnetic separators has been used in the mining and the recycling fields in general, and is still applied in wide variety of fields. It is classified into the equipments for separating coarse ferrous scrap from non-ferrous materials and the equipments for concentrating fine ferromagnetic particles below 3mm. Magnetic separation equipments for concentrating fine materials also falls into two categories of low intensity and high intensity magnetic separators. The former is used for ferromagnetic materials but also paramagnetic materials of high magnetic susceptibility, and the latter for paramagnetic materials of lower magnetic susceptibility. Both low and high intensity magnetic separators could be utilized either dry and wet. Recently, the High gradient magnetic separators(HGMS) used in the range of less than 0.7 tesla has been gradually replaced by the magnetic separator made of rare earth permanent magnets commercialized in the 1980s. In addition, the expansion of nanotechnology in terms of synthetic magnetic materials in the environmental and biological fields is expected to contribute positively to the development of magnetic separation technology.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.695-701
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• 2020

This study aimed to monitor a pilot-scale vertical flow reactor (VFR) system being operated in long-term for water quality control of pH-neutral mine drainage containing Fe, Mn and As, discharged in D mine site. The treatment systems of VFR and zero manganese reactor (ZMR) consisted of sand/limestone, and steel slag/limestone, respectively. The systems were operated during about six months in order to evaluate their long-term treatment efficiency It was observed that both pH and alkalinity of mine drainage were remarkably increased and more than 98% of Fe, As and Mn ions was continuously removed during the tested period of time. In conclusion, the field results of this work demonstrated that the vertical flow reactor system can effectively treat mine drainage contaminated by Fe, As and Mn.

• Tunnel and Underground Space
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• v.25 no.5
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• pp.408-416
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• 2015

The collapse of the underground cavities and voids, which were made for developing mineral resources, can cause the subsidence of the ground surface in the residential areas. During the Japanese colonial era and the 1960's mining boom period, lots of mines had been developed indiscriminately in Korea. Due to complicated geological conditions and mining methods, many of dangerous underground mine cavities with steep slopes had been generated at the shallow surface. Due to such conditions, it is difficult to directly apply valid foreign reclamation practice for the cavities in Korea environments. It is necessary to develop the efficient ground stabilization technologies for the Korea underground mine conditions to solve abandoned mine reclamation properly. Therefore, MIRECO and Korea government have been carrying out practical researches and technical developments together with other academic researchers and reclamation business partners, and various practical solutions such as surveying and exploration methods, proper cavity filling materials and reinforcement methods have been developed with application in the mine field. In this article, up to date technologies and R&D trends in the field of mine subsidence prevention technology are broadly reviewed to establish the future direction of a research and development.

• Economic and Environmental Geology
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• v.53 no.3
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• pp.235-244
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• 2020

Copper (Cu), one of the main contaminants in the mine drainage from the closed mine area, needs to be removed before exposed to environment because of its toxicity even in the low concentration. In this study, passive treatment based field pilot experiments using limestone and compost media were conducted during 9 months for enhancing Cu removal efficiency of the mine water treatment facility of S mine located in Goseong, Gyeongsangnam-do in South Korea. The pH increase and Cu removal efficiency showed high value at Successive Alkalinity Producing System ( SAPS) > Reducing and Alkalinity Producing System (RAPS) > limestone reactor in a sequence. The compost media using in SAPS and RAPS contributed to raise pH by organic material decomposition with generating alkalinity, thus, Cu removal efficiency increased. Also, experimental results showed that Cu removal efficiency was proportional to pH increase, meaning that pH increase is the main mechanism for Cu removal. Moreover, Sulfate Reduction Bacteria (SRB) was identified to be most activated in SAPS. It is inferred that the sulfate reduction reaction also contributed to Cu removal. This study has the site significance in that the experiments were conducted at the place where the mine water generates. In the future, the results will be useful to select the more effective reactive media used in the treatment facility, which is most appropriate to remediate mine water from the S mine.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.337-346
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• 2020

This study was carried out to evaluate the applicability of the soil washing process to remediation mercury-contaminated mine tailing or solid material (soil and sediments etc.) around abandoned mines. First, the physicochemical characteristics of mine tailing were analyzed through particle size analysis and sequential extraction. Secondly, laboratory scale washing experiments were performed using hydrochloric acid, nitric acid, potassium iodide and sodium thiosulfate. As a results of particle size analysis, mine tailing particle were concentrated below 40 mesh and the particle size below 200 mesh was the most analyzed. As a result of sequential extraction, elemental mercury fraction was analyzed as the highest with 69.12%, with strongly bound fraction 15.25% and residual and HgS fractions 11.97%, respectively. Laboratory scale washing experiments showed low applicability for nitric acid and sodium thiosulfate solutions. In case of hydrochloric acid solution, it was analyzed that mercury removal was possible at particle size of 200 mesh or more. Therefore, it is considered to be performed together with the physical sorting process. Potassium iodide solution was analyzed to have high washing efficiency at all concentrations and particle sizes. In particular, the mercury removal efficiency is high in the micro particles, and thus the applicability of the washing technology is the highest.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.771-779
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• 2020

This study was performed to develop a priority list for post-managements of leachates from 64 mine waste dump sites in Korea. For this, leachate quality, leachate quantity, and other factors were considered as evaluation criteria and the weights of 10 subfactors were calculated using Analytic Hierarchical Process (AHP) based on a survey from 20 experts in the field of mining environment. Calculated weights were 0.769, 0.147 and 0.084 for leachate quality, leachate quantity, and others, respectively, indicating that experts consider leachate quality as most important. Based on this approach, we classified the 64 mine waste dump sites into five grades from Grade I to Grade V. Ten were classified as Grade I, 1 as Grade II, 1 as Grade III, 33 as Grade IV, and 19 as Grade V.

• Tunnel and Underground Space
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• v.27 no.5
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• pp.295-302
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• 2017

In this study, a new quantitative instrumentation and measurement standards applicable to the field of mining has been proposed to improve the problems of the current measurement practices that apply the measuring standards of the civil engineering field (road, railway, etc.). With the data coordination of the mine reclamation corporation, we collected data on ground subsidence in the abandoned mine area, and studied various techniques for establishing a new management reference value based on the manual measurement data measured in the field. As a result, new instrumentation and measurement standards is set up and proposed by using statistics like the average value, the third quartile, the 95% confidence, and the maximum value.

• Journal of Soil and Groundwater Environment
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• v.25 no.4
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• pp.48-57
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• 2020

The objective of this study was to investigate the feasibility of organic compost for reducing soil loss in 25% sloped farm land. For the study, laboratory and field experiment were performed. After nine weeks monitoring in pot test, hardness of the amended soil with organic compost (1%~3%, w/w) showed two times higher than the control soil. Furthermore, soil loss of that was decreased by 95% under rainfall simulation test. From the result of laboratory experiment, organic compost with 2% (w/w) was applied for field experimental plot. After six month from April to September, the amount of soil loss became 67% of the initial, and the growth of natural vegetation was not hampered. Therefore, organic compost can be used as amendment materials to reduce soil loss in sloped farmland.

• Journal of Soil and Groundwater Environment
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• v.20 no.4
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• pp.83-89
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• 2015

Soil samples collected in an area of Gahak Mine were investigated for the characterization of mineralogical and physicochemical properties of contaminants in soils. It is found that soils in the study area are contaminated by lead (Pb), copper (Cu), zinc (Zn), cadmium (Cd), in which their concentrations are 595.3 mg/kg, 184.9 mg/kg, 712.8 mg/kg, and 10.64 mg/kg, respectively. All the concentrations exceed the concern criteria of Korean standard. Upon distribution patterns of metals identified by the sequential extraction procedure, our results show that more than 50% of metals are found as a residual type, and 30% are accounted for the association of Fe/Mn oxides. Interestingly, XRD results show that minium (Pb₃O₄) and cuprite (Cu₂O) are identified in the soil samples, suggesting that the sources of the contaminants for Pb and Cu are these minerals. In SEM images, tens of µm of Pb oxides and Pb silicate-minerals are observed. We, therefore, note that the contamination of metals in the study area results from the direct influx and disturbance of tailings. Our findings indicate that the characterization of physicochemical and mineralogical properties of contaminated soils is a critical factor and plays an important role in optimizing recovery treatments of soils contaminated in mine development areas.