• Title/Summary/Keyword: mineralogical

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한국에서 유황비료의 평가

  • Ryu K.S
    • Proceedings of the Mineralogical Society of Korea Conference
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    • 1996.10a
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    • pp.36-52
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    • 1996
  • 유황비료의 효과는 한국에서 널리 인정퇴고 있다. 유황은 토양 산도를 낮게 하고 과실의 당도를 증가 시켜 품질을 향상시킨다. 유황비료는 논과 밭토양에서 산도를 약간 변화시키며 특히 유황분말은 토양산도 교정에 유용하다. 한국농업은 질 높은 농산물을 점차 요구함에 따라 유황비료의 시용이 필요하게 될 것이다. 앞으로 유황비료에 대한 연구는 특별한 토양조건과 작물에서 적정 유황 수준을 밝혀내는 것이다.

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Mineralogical Analysis and Mechano-Chemical Purification of Natural Silica Ore for High Purity Silica Powder

  • Park, Jesik;Lee, Churl Kyoung;Lee, Hyun-Kwon
    • Korean Journal of Materials Research
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    • v.26 no.6
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    • pp.306-310
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    • 2016
  • To produce 4N grade high-purity silica powder from natural ore, the mineralogical characteristics of natural silica ore were investigated and their effects on the purification process were revealed. The Chinese silica mineral ore used was composed of iron and aluminum as main impurities and calcium, magnesium, potassium, sodium, and titanium as trace impurities; these trace impurities generally exist as either single oxides or complex oxides. It was confirmed that liberation and acidic washing of the impurities were highly dependent on the particle size of the ground silica ore and on its mineralogical characteristics such as the distribution and phases of existing impurities. It is suggested that appropriate size reduction of silica ore should be realized for optimized purification according to the origin of the natural silica ore. A single step purification process, the mechano-chemical washing (MCW) process, was proposed and verified in comparison with the conventional multi step washing process.

Effect of aggregate mineralogical properties on high strength concrete modulus of elasticity

  • Kaya, Mustafa;Komur, M. Aydin;Gursel, Ercin
    • Advances in concrete construction
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    • v.13 no.6
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    • pp.411-422
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    • 2022
  • Aggregates mineralogical, and petrographic properties directly affect the mechanical properties of the produced high strength. This study is focused on the effects of magmatic, sedimentary, and metamorphic aggregates on the performance of high strength concrete. In this study, the effect of the mineralogical properties of aggregates on the compressive strength and modulus of elasticity of high-strength concrete was estimated by Artifical Neural Network (ANN). To estimate the compressive strength and elasticity modules, 96 test specimens were produced. After 28 days under suitable conditions, tests were carried out to determine the compressive strength and modulus of elasticity of the test specimens. This study also focused on the application of artificial neural networks (ANN) to predict the 28-day compressive strength and the modulus of elasticity of high-strength concrete. An ANN model is developed, trained, and tested by using the available test data obtained from the experimental studies. The ANN model is found to predict the modulus of elasticity, and 28 days compressive strength of high strength concrete well, within the ranges of the input parameters. These comparisons show that ANNs have a strong potential to predict the compressive strength and modulus of elasticity of high-strength concrete over the range of input parameters considered.

Investigation of Phosphorus Species in Marine Sediment (해저 퇴적물에 함유된 인의 존재 형태에 대한 연구)

  • 김영규
    • Journal of the Mineralogical Society of Korea
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    • v.16 no.2
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    • pp.151-159
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    • 2003
  • $^{31}$ /P NMR and XRD have been used to study the mineralogical compositions and the phosphorus species in marine sediments near Wolsung nuclear power plant. The core samples with 30cm depth were investigated and no mineralogical changes have been found. The studied marine sediments were composed of quartz, albite, microcline, calcite, and some clay minerals such as illite, smectite, chlorite, and kaolinite. Only orthophosphate-monoester and very small amount of ortho-phosphate-diester were identified as phosphorus species in the studied sample, different from the species reported in other countries. These phosphorus species are mainly from organisms and was exposed to the oxic conditions. The consistent mineralogical compositions as well as the same phosphorus species throughout the entire core samples indicate that the constant oxic condition was kept without any changes in sedimentary conditions or the sediments were deposited with different sedimentary conditions, but later they were disturbed by other activities and exposed to the surface oxic conditions continuously.

Characteristics of Uraniferous Minerals in Daebo Granite and Significance of Mineral Species (대보화강암내 함우라늄 광물의 산출특징과 존재형태의 중요성)

  • 추창오
    • Journal of the Mineralogical Society of Korea
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    • v.15 no.1
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    • pp.11-21
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    • 2002
  • A mineralogical study was made in order to identify the relationship between uranium content in groundwater and rock chemistry using core rocks recovered from the drilling holes for wells in the Daebo Granite areas. Uraniferous minerals are of primary origin and occur as inclusions in accessory minerals such as zircon, monazite, and xenotime. Since the uraniferous minerals are very small to be 1 ~ 2 $\mu$m in size, it is difficult to distinguish their mineralogical species precisely. The frequent presence of dissolution cavities or dissolved textures in the accessory minerals suggests that uraniferous minerals dissolved partially and contributed to the groundwater chemistry. Because there is no clear relationship between host rocks and groundwater for uranium concentration, mineralogical characteristics of uraniferous minerals, together with aqueous geochemical conditions favorable for uranium dissolution, could play important roles in groundwaster chemistry.

Mineralogical Properties of Asian Dust in April 6 and 15, 2018, Korea (2018년 4월 6일과 15일 황사의 광물학적 특성)

  • Jeong, Gi Young
    • Journal of the Mineralogical Society of Korea
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    • v.31 no.2
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    • pp.103-111
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    • 2018
  • Mineralogical properties of two Asian dust (Hwangsa) samples collected during dust events in April 6 and 15, 2018 were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD analyses showed that Asian dusts were dominated by phyllosilicates (62 wt%) comprising illite-smectite series clay minerals (ISCMs) (55%), chlorite (3%) and kaolinite (4%). Nonphyllosilicate minerals were quartz (18%), plagioclase (9%), K-feldspar (3%), calcite (3%), and gypsum (2-4%). Mineral compositions determined by SEM chemical analyses were consistent with XRD data. ISCMs occur as submicron grains forming aggregate particles or coating coarse mineral grains such as quartz, plagioclase, K-feldspar, chlorite, and calcite. The ISCMs are often associated with calcite nanofibers and gypsum blades. Mineralogical properties of 2018 dusts were similar to those of previous dusts although clay contents were higher than that of coarse 2012 dust.

Mineralogical and Mechanical Properties of some Rocks as Aggregates and Their Suitabulity for Concrete (골재용 암석의 광물학적 및 역학적 특성과 콘크리트용으로서의 적합성 연구)

  • 진호일;민경원;연규석
    • Magazine of the Korea Concrete Institute
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    • v.10 no.4
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    • pp.183-193
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    • 1998
  • This study was designed, firstly, to determine the mineralogical and chemical characteristics of some rock aggregates, secondly, to offer interrelationships between those and mechanical properties, and thirdly, to evaluate their suitability for concrete aggregates. Mineralogical, chemical, physical and mechanical characteristics of the studied rock aggregates indicate that granite from BJ quarry and banded gneisses from KB. HI and SK quarry, and quartzite from the Hongcheon riverside are not proper to cement concrete aggregates because of quartz's potential possibility of alkali-silica reaction, and limestone in SY quarry is proper to asphalt concrete aggregates owing to dolomite causing alkali-carbonate reaction. Augen gneiss and diorite from KB and SA quarry, respectively, are to be not suitable for concrete aggregates because of biotite contents, but augen gneiss in HI quarry and gneisses in Hongcheon riverside are proper to concrete aggregates because of mineralogical and mechanical characteristics.