• Title/Summary/Keyword: LIMESTONE

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Calcination Characteristics of High-purity Limestone from the Pungchon Limestone in the Quicklime Manufacture (생석회 제조 공정에서의 풍촌층 고품위 석회석의 소성 특성)

  • Noh, Jin-Hwan;Lee, Hyun-Chul
    • Journal of the Mineralogical Society of Korea
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    • v.21 no.2
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    • pp.209-224
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    • 2008
  • Various types of high-purity limestone, which occurred in the Pungchon Formation, are examined to understand applied-mineralogical factors controlling their calcination characters with respect to the ore characters. To do this work, systematic characterization and determination were carried out for the limestone ores and their calcination products in a fixed heating condition, and the results were correlated and discussed. During the calcination experiment, a phase transition from calcite to quicklime begins to occur selectively in the physical weak zones such as grain boundary, cleavage and twin planes. All the fabrics of original limestones are preserved in the resultant quicklime. In addition, crystallinity of the quicklime was advanced, as the aging time of calcination was increased. Major controlling factors on the calcination effects of the high-purity limestone are elucidated to be the degree of development of cleavage and twin, together with crystallinity and textures in the limestone ore. Especially, lower crystallinity and dense interlocking fabrics obviously play advantageous role in all the calcination characters. But the development of cleavage and twin affects negatively on the calcination characters on account of favoring decrepitaion of quicklime in the lime manufacturing. Thus, the high-purity limestones characteristic of marble fabrics and relatively lower crystallinity are comparatively advantageous for the uses of lime manufacture.

Effects of Dietary Granular Ark Shell Partially Replacing Limestone on Laying Performance and Eggshell Quality in Aged Hens (산란사료 내 석회석에 대한 고막조개 패분의 부분 대체 급여가 산란후기의 난 생산성 및 난각질에 미치는 영향)

  • ark T. S.P;Ryu S. J.;Kim S. K.;Ahn B. K.;Kang C. W.
    • Korean Journal of Poultry Science
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    • v.31 no.3
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    • pp.177-185
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    • 2004
  • This experiment was conducted to examine the dietary effects of local granular ark shell(GAS) replacing limestone on egg shell quality in aged hens. A total of 200 Hy-Line Brown layers of 54-weeks-old were allotted into four treatments with five replications each. They were fed control(limestone only) 1% GAS, 2% GAS and 3% GAS diets for 6 weeks. GAS was substituted for coarse-type limestone at 0, 1, 2 or 3% of diet on weight basis. Particle sizes of limestone and GAS were within the ranges of 2~4 mm in diameters. In vitro HCl solubility of GAS was significantly lower(6.27 vs. 7.90%) compared to that of limestone(p < 0.05). The dietary treatment did not affect feed intake and egg production rate of the birds. Egg shell strength and thickness tended to be improved for birds fed the diets containing higher levels of GAS. The average egg shell strength and thickness of 2 or 3% GAS groups were significantly greater than those of the control (P < 0.05). The Tibial ash content of birds from 3% GAS group increased significantly as compared to that of the control. Tibial breaking strength, however, was not affected by the dietary treatment. Serum Ca and P contents of the birds were also not different among the dietary treatments. In conclusion, locally prepared GAS can be used as a calcium source in aged layer diet.

A Study on the Failure Cause of Large Scale Rock Slope in Limestone Quarries (석회석 광산에서 발생한 대규모 암반사면의 붕괴원인 분석에 관한 연구)

  • Lee, Sang-Eun;Kim, Hak-Sung;Jang, Yoon-Ho
    • Tunnel and Underground Space
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    • v.24 no.4
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    • pp.255-274
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    • 2014
  • The target of this study is large scale rock slope collapsed by around 7 pm on August, 2012, which is located at ${\bigcirc}{\bigcirc}$ limestone quarries of Gangneung city, Gangwondo. The slope prior to the collapse is formed as the height of about 200 m and the average inclination of $45^{\circ}$. The estimated amount of the collapse is about $1,500,000m^3$ with respect to the slope after the collapse. Geotechnical and field investigations such as boring, geophysical prospecting, surface geological survey, geological lineaments, borehole imaging, metric 3D imaging, experimental and field test, mining work by year, and daily rainfall were performed to find the cause of rock slope failure. Various analyzes using slope mass rating, stereonet projection, limit equilibrium method, continuum and non-continuum model were conducted to check of the stability of the slope. It is expected that the cause of slope failure from the results of various analysis and survey is due to the combined factors such as topography, rainfall, rock type and quality, discontinuities, geo-structural characteristics as the limestone cavity and fault zones, but the failure of slope in case of the analysis without the limestone cavity is not occurred. Safe factor of 0.66 was obtained from continuum analysis of the slope considering the limestone cavity, so the ultimate causes of slope failure is considered to be due to the influence of limestone cavity developed along fault zone.

Physicochemical Study of the Wondong Fe-Pb-Zn Skarn Deposit, Korea (원동(院洞) Fe-Pb-Zn 스카른광상의 물리화학적(物理化學的) 특징(特徵))

  • Chang, Ho Wan;Chang, Byung Uck
    • Economic and Environmental Geology
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    • v.25 no.1
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    • pp.1-16
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    • 1992
  • The Wondong Fe-Pb-Zn deposit is located in endo and exoskarns formed along the contact between the Makkol limestone interbedding pelitic limestone of Ordovician age and quartz porphyry of Cretaceous age. At the Wondong mine, the endoskarn shows a discontinuous zonal arrangement from quartz porphyry to pelitic limestone as follows: unaltered quartz porphyry, weakly altered quartz porphyry zone, intensively altered pinkish quartz porphyry zone, garnet zone, and greyish white and fine-grained clinopyroxene zone developed at pelitic limestone side. In terms of chemical mass balance, intensively altered pinkish quartz porphyry relative to unaltered quartz porphyry shows substantial enrichments in $K_2O$, $Na_2O$, and HREE and depletions in MgO, CaO, total $Fe_2O_3$, and LREE. On the other hand, garnet zone of endoskarn is enriched in CaO, MnO, total $Fe_2O_3$, MgO and depleted in $K_2O$, $Na_2O$. $Al_2O_3$ seems to be determining inert component. Thus the behavior of elements indicates that the mobility of elements depends on the equilibration of hydrothermal fluid and minerals and affects on enrichments by fractionation from and depletions by partition to hydrothermal fluid, respectively. Traversing toward pelitic limestone from a central zone of exoskarn, the exoskarn also shows a zonal arrangement as follows: garnet zone, clinopyroxene zone, and decolored pelitic limestone. The arrangement of mineral assemblages in skarns of the Wondong mine is the result of an increase in CaO and $K_2O$ toward the pelitic limestone. Skarn and ore minerals were formed in the following sequence: early skarn, late skarn and magnetite, pyrite, sphalerite, galena, and molybdenite. On the basis of stabilities of mineral assemblages, physicochemical conditions of the late skarn and magnetite mineralization are estimated to be $350^{\circ}C{\leq}T{\leq}400^{\circ}C$ at 1 Kb, $-23{\leq}log\;fO_2{\leq}-18$, and $0.005{\leq}XCO_2{\leq}0.01$, while those of the early skarn to be $420^{\circ}C{\leq}T{\leq}550^{\circ}C$ at 1 Kb.

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The Gravity Separation of Speiss and Limestone Granules Using Vibrating Zirconia Ball Bed (지르코니아볼층 진동을 이용한 스파이스와 석회석 입자의 비중선별)

  • Yoo, Jae Kyoung;Lee, Minji;Kim, Gyeong Hwan;Yoo, Kyoungkeun
    • Resources Recycling
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    • v.29 no.3
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    • pp.36-42
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    • 2020
  • In the present study, gravity separation of speiss (6.74 g/㎤) and limestone (2.7 g/㎤) was investigated using a vibrating 1 mm-zirconia ball (5.6 g/㎤) bed as a medium. The floating ratio and separation efficiency with increasing the number of spiess and limestone granules were examined by changing the vibration frequency from 18 Hz to 26 Hz. During the vibration, the zirconia balls circulate inside the vessel, and the spiess granules sink with the zirconia balls, but limestone granules remain on the surface of the zirconia ball bed. As the number of particles of spiess and limestone granules increased, it was observed that the granules were congested in the path of the granule sinking, so the rate of particle sinking decreased, and that limestone granules overlapping with the spiess granule also sunk. Therefore, the separation efficiency decreases with increasing the number of granules, but when the vibrational frequency increases, there is no more congestion and the separation efficiency increases. When each of the three particles was added, a separation efficiency of 100% was acheived at 22 Hz, which indicates that a dry gravity separation process that does not require a drying process is possible.

An Assessment of Utilization of the Pungchon Limestone in Paper Industry (풍촌층 석회석의 제지 산업에서의 응용성 평가)

  • Lee, Na-Kyong;Noh, Jin-Hwan
    • Journal of the Mineralogical Society of Korea
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    • v.20 no.4
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    • pp.339-349
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    • 2007
  • For various types of the Pungchon limestone, diverse mineral characters of the limestone including their size and morphology are investigated by using of ELS and SEM to examine the possibility of application as fillers to paper industry. Also, the measurement of zeta potential and the evaluation of coagulation properties in calcite suspension was made for fine powders of the limestone to examine the applicability and efficiency in wet-papermaking process. Fine powder of the Pungchon lime-stone, largely controlled by original mineral characters of ore in mineralogical aspects, exhibits some-what different trend in particle morphology according to ore types, and thereby, the size distribution, zeta potential and coagulation properties also become different. The examined whiteness, brightness, opacity and sheet strength in hand sheet also show remarkable differences according to ore types. These are seemed to be basically due to the results of combined effects of whiteness, site distribution, refractive index, and morphology of the limestone powder on the properties of hand sheet. Considering the investigated results, all types of the Pungchon limestone appear to be sufficiently applicable to paper industry. Especially, the mega-crystalline calcite type is evaluated to be overall suitable for the purpose of paper industry due to the higher values in whiteness and brightness. In addition the fine powder of micro-crystalline calcite type is assessed particularly to have a good quality in sheet strength by virtue of irregular particle shape.

perforation of tunnel in limestone formation (석회암층의 터널관통사례)

  • Kim, Yong-Il;Hwang, Nak-Yeon;Jeong, Du-Seok;Hong, Jong-Sang;Lee, Nae-Yong
    • Proceedings of the Korean Society for Rock Mechanics Conference
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    • 2007.03a
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    • pp.64-80
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    • 2007
  • This paper presents a case study on the excavation of a long tunnel(16.2km) named as "Sol-An tunnel", which connects between Mt. Dongbaek station and Dokye station in the Young-dong Railroad. This site is located in a complex geological region with faults, cavities and coal measures as sedimentary rocks area. It occurred geotechnical problems unexpectedly by running water when tunnelling in limestone area within those geological structures. This tunnel caused surface settlements through the decrease of ground water level and soil washed-out affecting by cavities and faults within limestone formation. This paper presents a analysis of source through a close investigation and measures. And also, does preventive measures about returns of settlements reflected by properties of limestones.

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Application of Limestone, Zeolite, and Crushed Concrete as Capping Material for Interrupting Heavy Metal Release from Marine Sediments and Reducing Sediment Oxygen Demand (해양퇴적물에서 중금속 용출 차단 및 퇴적물 산소 요구량 감소를 위한 석회석, 제올라이트 및 폐콘크리트의 피복 소재로서 적용)

  • Kang, Ku;Park, Seong-Jik
    • Journal of The Korean Society of Agricultural Engineers
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    • v.57 no.4
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    • pp.31-38
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    • 2015
  • This study aims to assess the effectiveness of limestone, zeolite, and crushed concrete as capping material to block the release of heavy metals (As, Cu, Cr, Ni, and Pb) and reduce the sediment oxygen demand. The efficiency of limestone, zeolite, and crushed concrete was evaluated in a reactor in which a 1-cm thick layer of capping materials was placed on the sediments collected from Inchon north harbor. Dissolved oxygen concentration and heavy metal concentration in seawater above the uncapped sediments and capping material were monitored for 17 days. The sediment oxygen demand was in the following increasing order: crushed concrete ($288.37mg/m^2{\cdot}d$) < zeolite ($428.96mg/m^2{\cdot}d$) < limestone ($904.53mg/m^2{\cdot}d$) < uncapped ($981.34mg/m^2{\cdot}d$). The capping materials could reduce the sediment oxygen demand by blocking the release of biochemical matters consuming dissolved oxygen in seawater. It was also shown that zeolite and crushed concrete could effectively block the release of Cu, Ni, and Pb but those were not effective for the interruption of As and Cr release from marine contaminated sediments.

On the Genesis of Ulsan Iron-Tungsten Deposits (울산(蔚山) 철(鐵)·중석(重石) 광상(鑛床)의 성인(成因))

  • Park, Ki Hwa;Park, Hee-In
    • Economic and Environmental Geology
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    • v.13 no.2
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    • pp.104-116
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    • 1980
  • The Ulsan mine is one of the largest contact metasomatic magnetite and scheelite deposits in the southeastern part of Korea. Mineralization at the Ulsan mine is localized along the contact between upper Cretaceous volcanic rocks and age unknown limestone which were intruded by 58 m.y. -old biotite-horndlende granite. General zonal sequence of skarn toward crystalline limestone from limestone-volcanics contact is grandite, grandite-salite and salite zones. On the otherhand volcanics origin skarns exhibits zonal sequences toward hornfels from boundary with limestone is garnet, garnet-epidote, and epidote zone. Compositions of garnets and clinopyro xenes are determined by the X-ray diffraction and reflective indecies. Local brecciation of these early skarns were followed by formation of the later skarn as zoned patches, breccia fillings and cross-cutting veins. Paragenetic sequence of late skarn minerals which is exhibited in the zoned patches and veins is an overlapping progression with time from andradite through hedenbergite or actinolite, quartz to calcite deposition. Magnetite metallization followed early formed skarns and pyrite pyrrhoite, sphalerite, galena, tennantite, scheelite and arsenopyrite deposition were simultaneously with hedenbergite, quartz and calcite of late skarn. Filling temperatures of fluid inclusions in calcites range from $160^{\circ}$ to $280^{\circ}C$.

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Chloride Diffusion in Mortars - Effect of the Use of Limestone Sand Part II: Immersion Test

  • Akrout, Khaoula;Ltifi, Mounir;Ouezdou, Mongi Ben
    • International Journal of Concrete Structures and Materials
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    • v.4 no.2
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    • pp.109-112
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    • 2010
  • Part I of this study was devoted to the electrical accelerated chloride diffusion in mortars. In this second part, natural chloride diffusion has been investigated for four types of mortars under exposure to a 0.5 mol/L NaCl solution for a period of up to 35 days. Two different types of sand were used for the production of test samples: siliceous sand (used as a reference) and limestone sand (used in this study). The effect of water to cement ratio and exposure time on the diffusion coefficients of mortars was also investigated. In this study, the total and free chloride content and penetration depth of mortar were measured after immersion, and Fick's second law of diffusion was fitted to the experimental data to determine the diffusion coefficient. Their results show that the use of crushed limestone sand in mortar had a positive effect on the chloride resistance. The apparent diffusion coefficient in all specimens was smaller than that in siliceous sand mortar. However, the chloride penetration of these mortars was increased as exposure time progressed.