• Title/Summary/Keyword: Limestone

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Fusulinids from the Carboniferous strata in the Gangdong area of Samcheok coalfield, Korea

  • Lee, Chang-Zin;Kim, Jun-Ho;Lee, Sang-Min
    • Journal of the Korean earth science society
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    • v.27 no.7
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    • pp.768-777
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    • 2006
  • The goal of this study is to elucidate the fusulinid biostratigraphy of the Carboniferous limestones distributed in the Gangdong area of Samcheok coalfield, Korea. The Carboniferous strata of the study area mainly comprise alternaton of dark gray shale, dark gray and reddish sandstone, and gray limestone. The limestones consist mainly of wackestonepackstone containing various fossil fragments such as crinoid, coral, brachiopod, foraminifera, fusulinid, and bryozoa; this observation thus suggests that the study site was the shallow marine environments. A tital of 12 species belonging to 5 genera of fusulinids are identified from the limestones of the Gangdong geologic section: Ozawainella turgida Sheng, Ozawainella sp. A, Ozawainella magna Sheng, Pseudostaffella antiqua (Dutkevich), Pseudostaffella paracompressa Safonova, Pseudostaffella kimi Cheong, Pseudostaffella sp., Beedeina lanceolata (Lee and Chen), Beedeina samarica (Rauser-Chernoussova), Beedeina sp. A, Neostaffella sphaeroidea cuboides Rauser-Chernoussova, and Hanostaffella hanensis Cheong. Such fusulinids species were reported from the lower part of the Geumcheon Formation in Samcheok coalfield and the middle Moscovian stage in Eurasia. On the basis of the fusulinid biostratigraphic correlation of the Gangdong geologic sections (A) to (C), the limestone should be overlapped by faults and folds. Moreover the stratigraphic thickness of the limestone is thinner than the thickness of the limestone outcrop of the Gangdong geologic section. Therefore, the stratigraphic sequence of the Gangdong geologic section is represented as the Gangdong geologic section (A).

Report on the Sam Han Chang Gun Manganese Deposits (삼한(三韓) 장군(將軍) 광산(鑛山) 조사(調査) 보문(報文))

  • Hwang, In Chon
    • Economic and Environmental Geology
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    • v.1 no.1
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    • pp.9-34
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    • 1968
  • Manganese ore deposits of the Samhan Changgun Properties are located at the valley of west-lope-side of Changgun-bong (1132m) occupied over the Myon border between Sochon-myon and Jaesan-myon Pongwha-gun, Kyongsang-Pukdo. Geology of the more property and it's vicinity consists of Wonnan formation and Yulri formation of pre-Cambrain and Changgun limestone formation, Mica-schist formation, quartizite formation and Jaesan formation (containing coal bearing zone the unknown age. And granites and dykes were intruded into the above formation later. 1. Management deposits is embedded the formation of Janggun limestone especially Contact zone in the contact zone to of Chunyang Granite limestone enclosed by Granite, and Maginal zone of fault line in the limestone. Therefore, Chunyang Granite is Closely related to ore deposit. Pegmatite which is near by ore deposit was intruded before mineralization and it seems to be a channelway of ore solution. The most important ore deposits of property grouped into south deposit, east deposit, east-Gachon deposit, South-Gachon deposit, Durimgok deposit and West deposit, out-crops at several place. Besides these deposits there also are several prospects on outcrop scathered. Hydrothermal alteration take place strongly in the well rock and it's sequence are Characterized as following; 1) Dolomitization 2) Carbonization 3) Mamgamotozation 4) Pyritization 5) Silicification 6) Oxidation 2. The grade of manganese dioxide is up to Mn 45% in Maximum, but generally, averaging Mn 30~35% of high grade ore and averaging Mn 30~32% of manganese carbonates are mined in his property.

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Geochemistry of Groundwater in Limestone and Granite of Hwanggangri Fluorite Mineralized Area (황강리 형석 광화대내 석회암 및 화강암지역 지하수의 지구화학적 특성)

  • Hwang, Jeong
    • Journal of the Korean earth science society
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    • v.23 no.6
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    • pp.486-493
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    • 2002
  • Hydrogeochemical characteristics of groundwater from a limestone and granite area were studied in the Hwanggangri district, where important fluorite ore deposits are distributed. The geochemical properties of groundwater from limestone and granite are commonly characterized as Ca$^{2+}$-HCO$_3\;^-$ and (Ca$^{2+}$+Na$^+$)-HCO$_3\;^-$ type, respectively. Groundwater, contaminated by mine drainage water from the neighboring ore deposits, has not been observed yet. However, fluoride in groundwater exceeding the drinking water permission level is found in the wells located in a Cretaceous granite area. The concentrations of F in the groundwater show a positive relationship with the values of Na, HCO$_3$, Li and pH. This may suggest that the groundwater come from the decomposition of fluoride-bearing silicate minerals within highly differentiated granitic rocks.

Compressive strength prediction of limestone filler concrete using artificial neural networks

  • Ayat, Hocine;Kellouche, Yasmina;Ghrici, Mohamed;Boukhatem, Bakhta
    • Advances in Computational Design
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    • v.3 no.3
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    • pp.289-302
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    • 2018
  • The use of optimum content of supplementary cementing materials (SCMs) such as limestone filler (LF) to blend with Portland cement has been resulted in many environmental and technical advantages, such as increase in physical properties, enhancement of sustainability in concrete industry and reducing $CO_2$ emission are well known. Artificial neural networks (ANNs) have been already applied in civil engineering to solve a wide variety of problems such as the prediction of concrete compressive strength. The feed forward back propagation (FFBP) algorithm and Tan-sigmoid transfer function were used for the ANNs training in this study. The training, testing and validation of data during the backpropagation training process yielded good correlations exceeding 97%. A parametric study was conducted to study the sensitivity of the developed model to certain essential parameters affecting the compressive strength of concrete. The effects and benefits of limestone filler on hardened properties of the concrete such as compressive strength were well established endorsing previous results in the literature. The results of this study revealed that the proposed ANNs model showed a high performance as a feasible and highly efficient tool for simulating the LF concrete compressive strength prediction.

A Study on the Recycling of Powdered Limestone for the Stable Reclamation of Tailings in an Abandoned Mine (폐광산 광미의 무해 처리를 위한 분말 석회석의 활용에 관한 연구)

  • Kim, Young-Seog;Oh, Jong-Kee;Kim, Sung-Gyu;Lee, Hwa-Young;Han, Choon
    • Resources Recycling
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    • v.9 no.2
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    • pp.26-32
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    • 2000
  • A period of widespread damage to the surroundings by acid mine drainage was examined by modeling using column device, and the method to solve this problem was worked out. the underlying principle is to let the tailings permanently maintain a stable state not being reacted with the underground water, and the method is that the tailings and limestone are piled up alternatively. This reclamation method is economic and environmentally useful because of practical use of a large amount of low-grade natural limestone.

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Effect of Different Substrate Characteristics on Abundance and Community Structure of Epilithic Diatoms in Two First-Order Streams

  • Ishida, Noriko;Iyoda, Yumi;Mitamura, Osamu;Choi, Jun-Kil
    • Korean Journal of Ecology and Environment
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    • v.41 no.2
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    • pp.137-143
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    • 2008
  • The abundance and community structure of epilithic diatoms grown on different substrata were investigated in two first-order streams located in a limestone and granite area, north of the Suzuka Mountains in Central Japan. Experiments were conducted as follows: limestone and granite without algae were submerged in their own streambed or another stream station and incubated for seven weeks, while limestone and granite with algae were transferred to another stream station and incubated at the same time. The diatom biomass was consistently high in the lime-stone station experiments compared to those at the granite station. In addition, there was more diatom biomass on granite substrata than on the limestone substrata at both stations. The present results suggested that the difference in water chemistry including the major nutrient concentrations was the limiting factor for algal growth in these two streams; however, when the water chemistry was the same in each stream, the difference in substratum characteristics became the important factor affecting the diatom abundance. The diatom community grown on the transferred substrata with and without algae became similar to those grown on the original substrata in each stream during the incubation period. It was suggested that the effect of the substrata characteristics on the diatom community structure was rather small.

A Study on the Removal Reaction Characteristics of Sulfur Dioxide (대기오염 물질인 $SO_2$ 제거반응 특성 연구)

  • 강순국;정명규
    • Journal of Environmental Science International
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    • v.4 no.1
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    • pp.41-52
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    • 1995
  • The effects of reaction temperature, SO2 and CO2 concentration in an air gas stream, particle sizes of limestone on the reactivity and capacity of SO2 removal have been determined in a thermogravimetric analyser(TGA). The apparent reaction order of sulfation reaction of pre-calcined lime(CaO) with respect to SO2 is found to be close to unity. The apparent activation energies are found to be 17,000 kcal/kmol for sulfation of pre-calcined lime and 19,500 kcal/kmol for direct sulfation of limestone(CaCO3). The initial sulfation reaction rate of pre-calcined lime increases with increasing temperature, whereas the sulfur capture capacity exhibits a maximum value at 90$0^{\circ}C$. In direct sulfation of limestone, sulfation reactivity and sulfur capature capacity of sorbent increase with increasing temperature and decreasing CO2 concentration in a gas bulk stream. The main pare of pre-calcined lime is shifted to the larger pore sizes and pore volume decreases with increasing sulfation time and temperature. The surface area of lime decreases with increasing calcination temperature under an air atmosphere, whereas is yearly constant under a CO2(5, 10%) atmosphere in a gas stream.

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Measures to Reduce Mine Hazards Caused by Open- cut Mining of Limestone Mines (석회석광산에서 노천채굴에 따른 광해 발생을 감소시키기 위한 대책)

  • Won, Yeon-Ho;Ah, Jin-Man
    • Explosives and Blasting
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    • v.24 no.2
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    • pp.75-82
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    • 2006
  • Most of limestone mines in Korea have been developed by a open-cut mining method in consideration of a deposited condition of ore, ore recovery, safety, economic efficiency, etc.. But it has produced environmental problems such as dust flying, blasting noise & vibration, and spoil of farmlands due to slope failure of waste rock mass caused by access road construction, fragmentation & crush of rocks, blasting, transportation, and mineral processing. In this study, it has been suggested for measures to reduce mine hazards caused by open- cut mining of limestone nines.

A Study on Environmental Impact Assessment on the Area Expansion of Limestone Mining with regard to Cumulative Impact Assessment (누적영향평가 측면에서 환경영향평가제도의 문제점과 개선방안 연구 - 석회석광산 채굴규모 확장을 대상으로 -)

  • Kim, Cho;Yeon, Ik-Jun;Jung, Ju-Yong;Lee, Sang-Woo
    • Journal of Environmental Impact Assessment
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    • v.23 no.1
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    • pp.1-9
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    • 2014
  • This study, focusing on the area expansion of limestone mines, identifies the problems of Environmental Impact Assessment(EIA) and what impact the current problems exert on another mines developing process. The legal relations analysis reveals that the Management of Mountainous Districts Act and other related laws effect on EIA process, especially the case of area expansion of limestone mines excluded from EIA. However, these problems can create mismatch with the policy goal of EIA system and have a negative impact on the environment in the future. A series of indepth interviews with managers in related agencies found that those agencies have been unaware of the seriousness of the problem. Without any strategy, negative result made by development activities would get more serious and sustainable development may not be possible at all. In order to solve these problems, government should modify the current interdependent legal provision and create the incentive structure to participate actively related agency in the EIA system.

Study on CO2 Emission Reduction Effects of Using Waste Cementitious Powder as an Alternative Raw Material

  • Park, Dong-Cheon;Kwon, Eun-Hee;Hwang, Jong-Uk;Ahn, Jae-Cheol
    • Journal of the Korea Institute of Building Construction
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    • v.14 no.2
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    • pp.187-194
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    • 2014
  • With environmental regulations continuously being strengthened internationally the need to control environmental pollution and environmental load is emerging in Korea. The purpose of this study is to seek methods or using waste cementitious powder as an alternative raw material for limestone through the optimization of raw material and to quantitatively analyze the resulting reduction of $CO_2$ emission in order to contribute to solving the issue of waste, which is the biggest issue in relation to construction and global warming. The results of the study, show that waste cementitious powder can be used as an alternative raw material for limestone at OPC level, but it was also found that mixing fine aggregate cementitious powder into waste cementitious powder significantly affected the substitution rate for limestone with waste cementitious powder and the reduction of greenhouse gas. In particular, when fine aggregate cementitious powder was used at a rate of 0~20%, the substitution rate for limestone and the reduction in the rate of greenhouse gas emission was significantly reduced. It is thought that a technique to efficiently separate and discharge the fine aggregate cementitious powder mixed in waste cementitious powder needs to be developed in the future.