• 터널과지하공간
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• 제26권4호
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• pp.274-282
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• 2016

현재 국내에서 가행 중인 석회석 광산은 자연환기력을 주된 환기방법으로 사용하고 있고, 대단면 굴착으로 매우 저속의 공기유동현상이 나타나고 있다. 이로 인하여 작업구간의 공기질이 매우 저하되어 있는 실정이다. 이러한 문제점들을 개선하기 위해서는 먼저 환기성능을 면밀하게 평가할 필요가 있다. 본 연구에서는 이러한 환기성능평가를 위해서 추적가스법을 적용하여 평가를 실시하였다. 연구 결과, 추적가스법을 통해 매우 저속의 공기유동, 공기재순환현상, 작업장 공기교환율 등을 정량적으로 평가함에 따라서 연구광산의 환기문제점들을 정밀하게 확인할 수 있었다. 이러한 추적가스법을 활용한 환기성능 평가방법은 광산의 작업환경 개선을 위하여 매우 정밀한 도구로 사용될 수 있음을 확인하였다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 INTERNATIONAL SYMPOSIUM ON SOIL & GROUNDWATER ENVIRONMENT
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• pp.59-61
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• 2005

In Korea, hundreds of abandoned and closed coal and metallic mines are present in the steep mountain valleys due to the depression of the mining industry since the late 1980s. From these mines, enormous amounts of coal waste were dumped on the slopes, which causes sedimentation and acid mine drainage (AMD) to be discharged directly into streams causing detrimental effects on soil and water environments. A limestone slurry by-product (lime cake) is produced from the Solvay process in manufacturing soda ash. It has very fine particles, low hydraulic conductivities ($10^{-8}{\sim}10^{-9}cm/sec$), high pH, high EC due to the presence of CaO, MgO and $CaCl_2$ as major components, and traces of heavy metals. Due to these properties, it has potential to be used as a neutralizer for acid-producing materials. A field plot experiment was used to test the application of lime cake for reclaiming coal wastes. Each plot was 20 x 5 m (L x W) in size on a 56% slope. Treatments included a control (waste only), calcite ($CaCO_3$), and lime cake. The lime requirement (LR) for the coal waste to pH 7.0 was determined and treatments consisted of adding 100%, 50%, and 25% of the LR. The lime cake and calcite were also applied in either a layer between the coal waste and topsoil or mixed into the topsoil and coal waste. Each plot was hydroseeded with grasses and planted with trees. In each plot, surface runoff and subsurface water were collected. The lime cake treatments increased the pH of coal waste from 3.5 to 6, and neutralized the pH of the runoff and leachate of the coal waste from 4.3 to 6.7.

• 자원환경지질
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• 제23권1호
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• pp.25-33
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• 1990

Gold-silver deposits of Deogheun and Beopjeon mines are composed of veins emplaced in Jurassic granite batholith. Based on ore structure and ore mineralogy, four distinct stages of mineral deposition are recognized in these ore deposits. Gold and silver minerals in Deogheun and Beopjeon-A ore deposits are precipitated in stage III and stage II, respectively. Mineral constituents of ores from these deposits are pyrite, sphalerite, arsenopyrite, pyrrhotite, chalcopyrite, galena, tetrahedrite, electrum, quartz and rhodochrosite. Cubanite, argentite and pyrargyrite occur only in Deogheun ore deposits. Ag content of electrum range from 42 to 66 atomic % in both ore deposits. Filling temperature of fluid inclusion from both ore deposits are as follows; stage I, $211-289^{\circ}$ ; stage II, $205-290^{\circ}$ ; stage III, $190-260^{\circ}$ ; stage IV, $136-222^{\circ}$ in Deogheun ore deposits. In Beopjeon-A ore deposits, stage I, $255-305^{\circ}$ ; stage II, $135-222^{\circ}$ ; stage III, $148-256^{\circ}$ ; stage IV, $103-134^{\circ}$. Salinities of fluid inclusions range from 1.6-8.5 wt. % equivalent NaCl in both ore deposits. Sulfur fugacities through stage II and III in Deogheun ore deposits inferred from data of mineral assemblage and fluid inclusion range from $10^{-11.0}-10^{-16.1}$1bars. Fluid pressure estimated from fluid inclusions which reveal boiling evidence range from 30-190 bars during mineralization in Deogheun ore deposits.

• Geomechanics and Engineering
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• 제11권3호
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• pp.401-420
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• 2016

The stability of deep coal roadways with large sections and thick top coal is a typical challenge in many coal mines in China. The innovative Universal Discrete Element Code (UDEC) trigon block is adopted to create a numerical model based on a case study at the Dongtan coal mine in China to better understand the failure mechanism and stability control mechanism of this kind of roadway. The failure process of an unsupported roadway is simulated, and the results suggest that the deformation of the roof is more serious than that of the sides and floor, especially in the center of the roof. The radial stress that is released is more intense than the tangential stress, while a large zone of relaxation appears around the roadway. The failure process begins from partial failure at roadway corners, and then propagates deeper into the roof and sides, finally resulting in large deformation in the roadway. A combined support system is proposed to support roadways based on an analysis of the simulation results. The numerical simulation and field monitoring suggest that the availability of this support method is feasible both in theory and practice, which can provide helpful references for research on the failure mechanisms and scientific support designing of engineering in deep coal mines.

• Geomechanics and Engineering
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• 제15권6호
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• pp.1173-1182
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• 2018

The coal wall, gob-side backfill, and gangues in goaf, constitute the support system for Gob-side entry retaining (GER) in coal mines. Reasonably allocating and utilizing their bearing capacities are key scientific and technical issues for the safety and economic benefits of the GER technology. At first, a mechanical model of GER was established and a governing equation for coordinated bearing of the coal-backfill-gangue support system was derived to reveal the coordinated bearing mechanism. Then, considering the bearing characteristics of the coal wall, gob-side backfill and gangues in goaf, their quantitative design methods were proposed, respectively. Next, taking the No. 2201 haulage roadway serving the No. 7 coal seam in Jiangjiawan Mine, China, as an example, the design calculations showed that the strains of both the coal wall and gob-side backfill were larger than their allowable strains and the rotational angle of the lateral main roof was larger than its allowable rotational angle. Finally, flexible-rigid composite supporting technology and roof cutting technology were designed and used. In situ investigations showed that the deformation and failure of surrounding rocks were well controlled and both the coal wall and gob-side backfill remained stable. Taking the coal wall, gob-side backfill and gangues in goaf as a whole system, this research takes full consideration of their bearing properties and provides a quantitative basis for design of the support system.

• 한국산학기술학회논문지
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• 제11권4호
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• pp.1163-1170
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• 2010

지뢰는 민간인을 무차별적으로 죽이고 불구로 만들기 때문에 인도주의에 이의를 제기한다. 지뢰는 군인과 민간인을 구별하지 않고, 수십년동안 작동하는 무기이다. 그 결과, 대부분 지뢰 희생자는 아무 죄가 없는 남녀노소이다. 이러한 목적으로 새로운 기술의 지뢰탐지 방법과 이동로봇이 필요한다. 우리의 연구는 지뢰탐지를 위한 소형 이동로봇을 개발하는 것과 지뢰 탐지, 탐지된 지뢰를 구분하는 것이다. 이 논문에서 전자기 센서를 사용하여 지뢰를 탐지했고, TRIZ의 6단계 창의성을 이용하여 탐지된 물체가 금속인지 M14 비금속 지뢰인지를 명확하게 판별하였으며, TRIZ를 이용한 새로운 지뢰 탐지 및 판별 방법을 제안하였다.

• 환경정책연구
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• 제8권1호
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• pp.129-143
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• 2009

국내 광산은 1960년대 및 70년대에 원료자원확보를 위한 기간산업으로 육성 개발되었고, 90년대 이후 광량 고갈 및 국제자원가격 하락으로 인한 채산성 악화로 거의 대부분의 광산이 폐광되었으며, 대다수의 폐광산의 폐광석 및 광미 적치장의 관리가 불안전하여 오염물질의 확산으로 토양과 수질이 오염되고 있는 실정이다. 이러한 토양오염실태에도 불구하고 정확한 중금속 오염원 파악 및 위해성을 인지하지 못한 상태에서 지속적으로 환경오염에 노출되어 있어, 이로 인한 주변생태계 파괴가 우려되는 상황이다. 이에 본 논문에서는 현재 진행 중인 지속가능한 휴폐광산 정화 및 관리를 위한 기존 환경 광산지리정보시스템 활용뿐만 아니라 추가적 기능 확대방법에 관한 제언을 통해 정책결정자 및 관리자들이 체계적이고 통합적인 광해방지정책 마련과 사업에 이바지할 수 있도록 할 것이다.

• Geomechanics and Engineering
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• 제12권6호
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• pp.1003-1020
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• 2017

Estimation of groundwater inflow into underground opening is of critical importance for the design and construction of underground structures. Groundwater inflow into a pilot underground storage facility in China was estimated using analytical equations, numerical modeling and field measurement. The applicability of analytical and numerical methods was examined by comparing the estimated and measured results. Field geological investigation indicated that in local scale the high groundwater inflows are associated with the appearance of open joints, fractured zone or dykes induced by shear and/or tensile tectonic stresses. It was found that 8 groundwater inflow spots with high inflow rates account for about 82% of the total rate for the 9 caverns. On the prediction of the magnitude of groundwater inflow rate, it was found that could both (Finite Element Method) FEM and (Discrete Element Method) DEM perform better than analytical equations, due to the fact that in analytical equations simplified assumptions were adopted. However, on the prediction of the spatial distribution estimation of groundwater inflow, both analytical and numerical methods failed to predict at the present state. Nevertheless, numerical simulations would prevail over analytical methods to predict the distribution if more details in the simulations were taken into consideration.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.482-488
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• 2001

Platinum group metals (pgm) are useful to many industries such as chemical, dental and medical, petroleum, refining, electrical and electronic, and automotive. Researchers at the South Dakota School of Mines and Technology and PGM Recovery Ltd. have developed jointly an environmentally sound and metallurgically efficient process for extracting these metals from secondary sources. Once these metals have been dissolved in the leach liquor, the individual metals mainly platinum, palladium, and rhodium, should be separated in order to recover the individual metals with high purity. During this investigation, solvent extraction has been chosen as the method used to achieve the separation and extraction of platinum, palladium, and rhodium from the leach liquor. There were three solutions used throughout this procedure: 1) Synthetic solution (200 ppm Pt 80 ppm Pd 20 ppm Rh; 300 ppm Pt, 180 ppm Pd 50 ppm Rh), and 2) Auto catalyst leach liquors (100 ppm Pt, 30 ppm Pd, 20 ppm Rh). The solvents investigated included Lix 84(2-hydroxy-5-nonylacetonphenone oxime in a mixture with 5-dodecylsalicyloxime), Lix 84-I, ACORGA CLX-50 (diester of pyridine 3,5 dicarboxylic acid), and di-hexyl sulfide. The extraction values achieved using ACORGA CLX-50, Lix 84, and Lix 84-I were respectively Pt (25%, 0% 0%), Pd (100%, 99.8%, 95.3%), and Rh (99.1%, 35.5%, 4.25%). The stripping processes for the Lix 84, and Lix 84-I were proven to be more involved than others. The solutions were required to be simultaneously heated and stirred. The percentages acquired through these processes yielded unsatisfactory results. The stripping procedure for the ACORGA CLX-50 was easier to execute, yet the percentage recovered from this process was also unsatisfactory. Overall the di-hexyl sulfide has proved to be the most successful organic for this procedure. The average percent extracted for palladium was excellent with 99.9% - 100% with very little Platinum and rhodium extracted. The ability of stripping palladium in ammonia solution was also found to be excellent.

• 암석학회지
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• 제15권2호
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• pp.81-89
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• 2006

전라북도 지방에 분포하는 번암, 동진, 적상 및 북창 광산에서 채취한 납광석광물에 대한 납 동위원소 분석을 실시하였다. 그 결과 광상별로 상당히 다른 납 동위원소 조성을 가짐을 확인하였다. 번암광산, 북창광산 및 동진광산의 납 동위원소값이 형성하는 선형변화는 그 기울기가 매우 급하기 때문에 연대로 해석하기는 곤란하며 이 광상들의 납은 주로 선캠브리아 기저지각과 중생대 화강암질암의 두 종류 단성분들로부터 유래하였을 가능성을 제기하였다. 광상의 형성시 이러한 근원물질들로부터 유래한 납의 혼합비율은 광상마다 상당히 다른 것으로 추정된다. 이는 광화작용시 존재했던 유체의 순환이 매우 국지적인 범위에서 제한적으로 이루어졌기 때문인 것으로 판단된다 동진 광상의 경우는 광상에 배태된 납의 근원이 상당부분 기저지각에서 용출된 것임을 시사하며, 광화작용시 화성암은 운광암으로서보다는 유체의 순환을 야기한 열원으로서 중요한 역할을 담당한 것으로 판단된다.