• Journal of Industrial Technology
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• v.30 no.A
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• pp.17-23
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• 2010

Recently, a large number of open-pit mines are planning to change their mining method to underground types because the environmental concerns and legal regulations are increased with a rise in the standard of living. The K silica mine, which is one of them and located in Kyunggi province, is planning the establishment of a vertical shaft which will be used for ore-pass channel in their new glory hole mining method. This vertical shaft will be designed to join with a horizontal gangway excavated from the ground level. In this new mining system, the excavated ore particles will be stored inside a shaft and transported out with a help of a conveyor belt. Therefore the hang-up of ore particles in a shaft, the control of gate at the bottom of a shaft, the installation of dog-leg at the gate should be investigated identically. In this study, the PFC-2D code which is one of the discrete element numerical methods has been applied to simulate the particle flow mechanism in a shaft, and the optimum mine design has been proposed to maximize the productivity and to minimize the system damage.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.4
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• pp.101-107
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• 2008

Due to increased interest in environmental friendly ecological development and restoration, civil appeals concerning various environmental and landscape problems are continuously being lodged in cases where open-pit limestone mines are situated in places with eminent natural landscape. In this study, with the open-pit limestone mines located in the Baekdu mountain range as a study area, intends to contribute in recognition of various environmental problems and in the promotion of a reasonable restoration plan through high quality geo-spatial information. And it is planning to establish a method for sustained monitoring of the limestone mining by building intelligent national land information of the study area through combining Airborne Laser Scanning and Terrestrial LiDAR based surveying.

• Tunnel and Underground Space
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• v.32 no.5
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• pp.327-343
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• 2022

The standard work report for trucks was developed that records data on truck haulage operations in open-pit and underground mines, and to evaluate the performance of haulage operations. Work reports used in 5 mines in Korea was secured and analyzed, and items to be included in the standard work report were determined. By analyzing the formulas for key performance indicators (KPIs) proposed by the Global Mining Guidelines Group (GMG), it was possible to determine how to record time-related data. After selecting a limestone underground mine as a research area, the performance of haulage operations was evaluated using a standard work report. As a result, in terms of truck availability, uptime was 46.7%, and both physical and mechanical availability were 100%. In the case of utilization, use of availability was 88.2%, the asset utilization was 41.1%, and operating and effective utilization were 88.2% and 79.2%, respectively. Also, in terms of efficiency, operating efficiency was found to be 89.9%.

• Explosives and Blasting
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• v.24 no.1
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• pp.1-8
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• 2006

Recently, most of limestone quarries have been not mined by open-pit mining but by underground excavation to reduce environmental pollution. As a result, the size of underground galleries became bigger to maintain mass-production close to open-pit mining. However, the scale of pillars and galleries as well as the excavation methods may induce a few adverse problems for the stability of a mined gallery. In this study, the nomogram analysis and the prediction of rock damage zone induced by blasting were carried out. The testing conditions include concurrent blasting of two adjacent galleries, concurrent blasting of a transport drift and a inclined shaft, sequential blasting of two galleries, and separate blasting for each gallery. For each testing condition, blast vibration velocity was measured and analyzed. From the prediction formulas for blast vibration velocity derived in this study, the maximum depth of rock damage zone induced by blasting were also predicted.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.531-542
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• 2021

Open-pit mines require constant monitoring as they can cause surface changes and environmental disturbances. In open-pit mines, there is little vegetation at the mining site and can be monitored using InSAR (Interferometric Synthetic Aperture Radar) coherence imageries. In this study, activities occurring in mine were analyzed by applying the recently developed InSAR coherence-based NDAI (Normalized Difference Activity Index). The March 5 Youth Mine is a North Korean mine whose development has been expanded since 2008. NDAI analysis was performed with InSAR coherence imageries obtained using Sentinel-1 SAR images taken at 12-day intervals in the March 5 Youth Mine. First, the area where the elevation decreased by about 75.24 m and increased by about 9.85 m over the 14 years from 2000 was defined as the mining site and the tailings piles. Then, the NDAI images were used for time series analysis at various time intervals. Over the entire period (2017-2019), average mining activity was relatively active at the center of the mining area. In order to find out more detailed changes in the surface activity of the mine, the time interval was reduced and the activity was observed over a 1-year period. In 2017, we analyzed changes in mining operations before and after artificial earthquakes based on seismic data and NDAI images. After the large-scale blasting that occurred on 30 April 2017, activity was detected west of the mining area. It is estimated that the size of the mining area was enlarged by two blasts on 30 September 2017. The time-averaged NDAI images used to perform detailed time-series analysis were generated over a period of 1 year and 4 months, and then composited into RGB images. Annual analysis of activity confirmed an active region in the northeast of the mining area in 2018 and found the characteristic activity of the expansion of tailings piles in 2019. Time series analysis using NDAI was able to detect random surface changes in open-pit mines that are difficult to identify with optical images. Especially in areas where in situ data is not available, remote sensing can effectively perform mining activity analysis.

• Industrial Engineering and Management Systems
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• v.11 no.1
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• pp.94-102
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• 2012

In this paper, an interactive planning and scheduling framework are proposed for optimising operations from pits to crushers in ore mining industry. Series of theoretical and practical operations research techniques are investigated to improve the overall efficiency of mining systems due to the facts that mining managers need to tackle optimisation problems within different horizons and with different levels of detail. Under this framework, mine design planning, mine production sequencing and mine transportation scheduling models are integrated and interacted within a whole optimisation system. The proposed integrated framework could be used by mining industry for reducing equipment costs, improving the production efficiency and maximising the net present value.

• Economic and Environmental Geology
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• v.27 no.6
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• pp.601-609
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• 1994

Uranium resources of Mongolia are generally confined to sediments deposited during Jurassic to Cretaceous volcanism. Territory of Mongolian uranium deposits is divided into four districts as follows; Mongol-Priargun, Gobi-Tamtsag, Hentii-Dauer, North-Mongolian. Potential uranium deposits were discovered by Airborne Gamma ray Spectrometric Survey(AGSM). One of them, Haraat deposit, which was interested to us, has been under detailed survey for exploitation by one of American companies, Concord company. The Erdes uranium mine is partly operated by about hundred Russian staffs at the open pit, while underground mining facilities such as the main hoist are almost closed. Ore minerals of the Erdes Mine are coffinite and pitchblende. Uranium content in ore ranges from 0.06% to 1%, averaging 0.2%. Ore reserves of uranium ore in the Dornod deposit including the Erdes Mine accounts 29,000 ton. It is reported that Uranium resources of Mongolia are 1,471,000 ton.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.1
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• pp.43-48
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• 2020

Open pit mines for limestone mining require rapid development of technologies and efforts to prevent safety accidents due to rapid deterioration of the slope due to deforestation and rapid changes in the topography. Accurate three-dimensional spatial information on the terrain should be the basis for reducing environmental degradation and safe development of open pit mines. Therefore, this study constructed spatial information about open pit mine using UAV(Unmanned Aerial Vehicle) and analyzed its utility. images and 3D laser scan data were acquired using UAV, and digital surface model, digital elevation model and ortho image were generated through data processing. DSM(Digital Surface Model) and ortho image were constructed using image obtained from UAV. Trees were removed using 3D laser scan data and numerical elevation models were produced. As a result of the accuracy analysis compared with the check points, the accuracy of the digital surface model and the digital elevation model was about 11cm and 8cm, respectively. The use of three-dimensional geospatial information in the mineral resource development field will greatly contribute to effective mine management and prevention of safety accidents.

• Geomechanics and Engineering
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• v.15 no.1
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• pp.669-676
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• 2018

The "pseudo-wedge" failure is a name for a complex instability occurring at the Sarcheshmeh open-pit mine (Iran). The pseudo-wedge failure contains both the rock bridge failure and sliding along pre-existing discontinuities. In this paper, a cross section of the failure area was first modeled using a bonded-particle method. The results indicated development of tensile cracks at the slope toe which explains the freedom of pseudo-wedge blocks to slide. Then, a three-dimensional discrete element method was used to perform a block analysis of the instability. The technique of shear strength reduction was used to calculate the factor of safety. Finally, the influence of geometrical characteristics of the mine wall on the pseudo-wedge failure was investigated. The safety factor significantly increases as the dip and dip direction of the wall decrease, and reaches an acceptable value with a 10-degree decrease of them.

• Geomechanics and Engineering
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• v.31 no.5
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• pp.529-543
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• 2022

The lattice-spring-based synthetic rock mass model (LS-SRM) technique has been extensively employed in large open-pit mining and underground projects in the last decade. Since the LS-SRM requires a complex and time-consuming calibration process, a robust approach was developed using the Response Surface Methodology (RSM) to optimize the calibration procedure. For this purpose, numerical models were designed using the Box-Behnken Design technique, and numerical simulations were performed under uniaxial and triaxial stress states. The model input parameters represented the models' micro-mechanical (lattice) properties and the macro-scale properties, including uniaxial compressive strength (UCS), elastic modulus, cohesion, and friction angle constitute the output parameters of the model. The results from RSM models indicate that the lattice UCS and lattice friction angle are the most influential parameters on the macro-scale UCS of the specimen. Moreover, lattice UCS and elastic modulus mainly control macro-scale cohesion. Lattice friction angle (flat joint fiction angle) and lattice elastic modulus affect the macro-scale friction angle. Model validation was performed using physical laboratory experiment results, ranging from weak to hard rock. The results indicated that the RSM model could be employed to calibrate LS-SRM numerical models without a trial-and-error process.