• Title/Summary/Keyword: iron mineralogy

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Mineralogical and Gechemical Studies of Titaniferous Iron Ores and Ultramafic to Mafic Rocks from the Boreundo Iron Ore Deposits, South Korea (볼음도 자철광상의 초염기성-염기성암과 티타늄자철광석의 광물 및 지구화학적 연구)

  • 김규한
    • Economic and Environmental Geology
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    • v.33 no.1
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    • pp.1-18
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    • 2000
  • Lens shaped and stratiform titanomagnetite orebodies in the Boreumdo iron mine are closely associated with amphibolite which intruded into Precambrian metasediments. Mineralogical and petrochemical analyses of amphilbolite and titanomagnetite ores were carried out in order to interpret the origin of amphilbolite and the genesis of titanomagnetite ore deposits. Amphibolites belong to orthoamphilbolite interms of Niggli value and mineralogy, and are characterized by the occurrence of relict olivine. The amphilbolites responsible for titanomagnetite mineralization have extremely high content of $TiO_2$, ranging from 2.12 to 4.59 wt.% with the average value of 3.43 wt.%. Amphibole minerals in amphibolites are consist mainly of calcic amphiboles such as hornblende, ferroan pargasitic hornblende and tremolite. Most plagioclases belong to andesine ($An_{30-50}$\ulcorner). The metamorphic temperature and geobarometric pressure which are calculated by the calcic amphibole-plagioclase geothermometer and calcic amphilbole geobarometer are estimated to be 537$^{\circ}C$~579$^{\circ}C$(avg. 555$^{\circ}C$) and 2.9~6.6 kbar (avg. 4.5 kbars), respectively. It shows a typical amphibolite facies. Based on the mineral chemistry and petrochemisty of amphibolites and iron ores which are composed mainly of titanomagnetite and ilmenite in the Boreumdo iron mine, the titaniferous oxide melts could be immiscibly separatd from the titaniferous ultrabasic magma. The genesis of the Boreumdo titanomagnetite ore deposits are analogous to the Soyeonpyeongdo and Yonchon iron ore deposits in terms of their mineralogy, mineral chemistry and geologic setting.

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Structural control, and Correlation of Uranium Distribution and Mineralogy of Meta-pelites in Ogcheon Terrain, Korea (한반도(韓半島) 옥천대(沃川帶)에 분포(分布)하는 함(含)우라늄층(層)의 지질구조규제(地質構造規制) 및 조성광물(組成鑛物)과 우라늄분포(分布)와의 상관관계연구(相關關係硏究))

  • Park, Bong-Soon;So, Chil-Sup
    • Economic and Environmental Geology
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    • v.13 no.4
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    • pp.215-227
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    • 1980
  • The rock units of Goesan area in the Ogcheon metamor phic terrain established on the basis of field criteria should be redefined into following sequence. Based on shear senses in secondary small structures which are usually observable in the investigated area, the stratigraphy can be lithologically divided into the lower pelite, pebbly mudstone, upper pelite, quartzite and psammite unit in ascending order. This conclusion is in discordance with a previous opinion; Munjuri formation and Guryongsan formation may be equivalent to upper pelite unit, Iwonri formation and Hwanggangri formation to pebbly mudstone. From this, it may be inferred that isoclinal overturned folds repeatly occur in the area. The uranium bearing coaly thin layers in upper pelite unit have relatively broad exposures in Deogpyeongri block of Goesan area along culmination zone in the central part of the investigated area. It is believed that structural feature in the block recognized complexly refolded synform plunging to southwest. Mineralogical and radiometric studies were made on 135 representative samples from the Ogcheon Group of Korea. The mineralogy of all black slate samples is qualitatively similar but quantitatively ·different. The uranium distribution in the studied area show approximately log normal. Uranium in the black slates of the Ogcheon Group was deposited together under same physico-chemical environmental conditions. The chemical and geological factors that controlled the abundance of organic carbon and iron oxides also controlled the uranium content. The relationship of the major components to uranium can be expressed by the following regression equation: $Log(U\times10^4+1)$= 1.70999-0.00367(quartz)0.00512(micas)-0.00930 (other silicates)+0.01911 (iron oxides)-0.03389(other opaques)+0.02062(organic carbon).

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Mineralogy and Iron Chemistry of Garnets and Clinopyroxenes in the Skarn Deposits, the Hambaek Geosyncline Belt, Korea (함백지향내의 스카른광상에서 산출되는 석류석과 단사휘석의 광물학과 철화학)

  • 최진범;김수진
    • Journal of the Mineralogical Society of Korea
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    • v.4 no.2
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    • pp.119-128
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    • 1991
  • In the southern limb of the Hambaek geosyncline belt, large-scaled skarn deposits are developed in the Cambro-Ordovician sedimentary rocks of the Chosun Supergroup. They are the Sangdong tungsten deposit, Geodo iron-copper deposit, Yeonhwa I and II lead-zinc deposits, and Ulchin zinc-lead deposit, all of which are associated with various skarn minerals. Though different occurrences and paragenesis are found in different deposits, most skarn deposits always have skarns of garnet (andradite-grossular series) and clinopyroxene(heden-bergite-diopside series). Andradite and hedenbergite are Fe-dominant members, but show different oxidation states, that is, Fe3+ for andradite and Fe2+ for hedenbergite. According to iron chemistry and log([Fe/Al]gd/[Fe/Mg]cpx) derived from equilibrium reactions, the diopside-andradite and hedenbergite-grossular pairs suggest the oxidized state (dian type) and reduced state (hegro type), respectively. Among skarn deposits developed in the Hambaek geosynline, it can be classified that the Geodo and Yeonhwa I skarns are of dian type, while the Sangdong, Yeonhwa II, and Ulchin deposits are of hegro type. This classification is not applicable to all kinds of skarn deposits, but may be applicable to such deposits as are more controlled by oxygen fugacity than composition of skarn fluid.

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Rare Metal Chemistry, Microstructures, and Mineralogy of Coal Ash from Thermal Power Plants of Korea (화력발전소 석탄회의 희유금속화학, 미세구조, 광물학적 특성)

  • Jeong, Gi Young;Kim, Seok-Hwi;Kim, Kangjoo
    • Journal of the Mineralogical Society of Korea
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    • v.28 no.2
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    • pp.147-163
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    • 2015
  • Chemical and mineralogical properties of coal ash samples from the nine thermal power plants of Korea were investigated to acquire basic data for estimating the potential of rare metal recovery. Chemical compositions of coal ash were consistent with those of average shale and foreign coal ashes. However, there were small differences between the metal contents of domestic anthracitic and imported bituminous coal ashes. Unburned coal particles were much abundant in the ash of domestic anthracitic coal. Chalcophile elements were relatively enriched in the fly ash compared to bottom ash. Silicate glass was the major component of coal ash with minor minerals such as quartz, illite (muscovite), mullite, magnetite, lime, and anhydrite. Al and Si were the major components of the glass with varying contents of Ca, Fe, K, and Mg. Glass occurred in a form of porous sphere and irregular pumace-like grain often fused with iron oxide spheres or other glass grains. Iron oxide spheres were fine intergrowth of fast-grown iron oxide crystals in the matrix of silicate glass. Chemical, microstructural, and mineralogical properties would guide successful rare metal recovery from coal ash.

Applied Mineralogy for the Conservation of Dinosaur Tracks in the Goseong Interchange Area (35번 고속도로 고성 교차로 지역 공룡발자국의 보존을 위한 응용광물학적 연구)

  • Jeong Gi Young;Kim Soo Jin
    • Journal of the Mineralogical Society of Korea
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    • v.17 no.3
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    • pp.189-199
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    • 2004
  • Cretaceous sedimentary rocks bearing dinosaur tracks in the Goseong interchange area were studied for their conservation and public display in the aspect of applied mineralogy. Black clay layers alternate with silt layers in the sedimentary rocks. The verical and horizontal fissures are commonly filled with calcite veinlets, supergenetic iron and manganese oxides. The rocks are composed of quartz, albite, K-feldspar, calcite, chlorite, illite, muscovite, and biotite, with minor apatite and rutile. Silt layers are relatively rich in calcite and albite, whereas clay layers are abundant in quartz, illite, and chlorite. Al, Fe, Mg, K, Ti, and P are enriched in the clay layers, while Ca, Na, and Mn in silt. Most of trace elements including V, Cr, Co, Ni, Cs, Zr, REE, Th, and U are enriched in clay layers. Inorganic carbon are present in silt layers as calcite, while organic carbon in black clay layers. The black clay layers were partly altered to yellow clay layers along the fissures, simultaneously with the decrease of organic carbon. Selective exfoliation of clay-rich black and yellow clay layers, calcite matrix of silt layers and calcite infillings of fissures are estimated as the major weakness potentially promoting chemical and physical degradation of the track-bearing rock specimens.

Compositional Variations of Sphalerites and Their Genetic Characteristics from Gold and/or Silver Deposits in Central Korea (한국 중부지역 금은광상산 섬아연석의 조성변화와 성인적 특성)

  • Choi, Seon-Gyu
    • Economic and Environmental Geology
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    • v.26 no.2
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    • pp.135-143
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    • 1993
  • Chemical compositions of sphalerites from 25 gold and/or silver deposits in central Korea were obtained with an electron probe microanalyzer. The FeS contents of sphalerites depend generally upon the assemblage of associated iron sulphides (pyrite and/or pyrrhotite) especially. The sphalerites coexisting with pyrrhotite show a narrow range of FeS variation, but the sphalerites associated with pyrite and/or pyrrhotite have the variable and wide range of FeS contents. The sphalerites from Au-dominant deposits, which vary considerably in each deposit, are generally characterized by high CdS content and low MnS content. On the contrary, the sphalerites from Ag-dominant and Au-Ag deposits tend to be characterized by relatively high MnS and very low CdS content. Based upon the mineralogy, fluid inclusions and stable isotope data, the Au-dominant deposits were formed under higher temperature and deeper depth than the Ag-dominant and Au-Ag deposits. The results suggest the possibility that the diverse sources and evolution of ore fluid at the time of ore deposition are responsible for the deposition of Cd and Mn components in sphalerites.

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Mineralogy and Geochemistry of Iron Hydroxides in the Stream of Abandoned Gold Mine in Kwangyang, Korea (광양 폐금광 수계에 형성된 철수산화물에 대한 광물학적 및 지구화학적 특성)

  • Park, Cheon-Young;Jeoung, Yeon-Joong;Kim, Seoung-Ku
    • Journal of the Korean earth science society
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    • v.22 no.3
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    • pp.208-222
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    • 2001
  • Geochemical investigations on suspended amorphous iron oxide material from the Kwangyang gold mine and its surrounding area, Cheonnam, Korea have been carried out. The sediments samples were collected from 11 location along Kwangyang mine area and were air dried and sieved to -80 mesh. These samples consist mainly of iron, silicon and alumina. The Fe$_2$O$_3$ contents ranges from 17.9 wt.% to 72.3 wt.%. The content of Fe$_2$O$_3$ increase with decreasing Si, Al, Mg, Na, K, Mn, and Ti, whereas the contents of Te, Au, Ga, Bi, Cd, Hg, Sb, and Se increase in the amorphous stream sediments. Amorphous stream sediments have been severely enriched for As (up to 54.9 ppm), Bi (up to 3.77 ppm), Cd (up to 3.65 ppm), Hg (up to 64 ppm), Sb (up to 10.1 ppm), Cu (up to 37.1 ppm), Mo (up to 8.86 ppm), Pb (up to 9.45 ppm) and Zn (up to 29.7 ppm). At the upstream site, the Au content (up to 4.4 ppm) in the amorphous stream sediments are relatively high but those contents decrease with distance of mine location. The content of Ag (up to 0.24 ppm) were low in upstream site but those contents increase significantly in the downstream sites. The X-ray diffraction patterns of the samples have virtually no sharp and discrete peaks, indicating that some samples are amorphous or poorly-ordered. The quartz, goethite, kaolinite and illite were associated in amorphous stream sediments. The infrared spectra for amorphous stream sediments show major absorption bands due to OH stretching, adsorbed molecular water, sulfate and Fe-O stretching, respectively.

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Siderite and Siderostone from the Sangdong Mine, Yeongweol-gun, Korea (강원도(江原道) 상동광산(上東鑛山)에서 발견(發見)된 능철석(菱鐵石) 및 능철석암(菱鐵石岩))

  • Kim, Soo Jin;Chang, Se-Won
    • Journal of the Mineralogical Society of Korea
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    • v.2 no.2
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    • pp.73-80
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    • 1989
  • The sedimentary siderite rock or siderostone has been firstly found from the upper part of the Cambrian Myobong Slate in the Sangdong Tungsten Mine area. It occurs as layers between slate and calc-silicate rock (originally siliceous ankerite rock and ferroan dolostone) or within calc-silicate rock. Some parts of the siderostone bed, however, are considerably skarnized to iron-rich skarns, leaving only small-scaled relics. Siderostone consists mainly of siderite and quartz with minor amount of bertioerine and fluorite or apatite and is commonly microcrystalling granular in texture. Stratification is well developed in some siderstone. The siderostone and its skarnized rocks occasionally contain scheelite grains. Siderite also occurs in sandstone and slate. Mineralogy and textures of the siderostone suggest that it might be formed in the shallow marine basin where enough organic matter was present to maintain a low Eh and iron was supplied, and that siderite might be formed largely by diagenesis from iron-rich berthierine mud.

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Titanium Geology and Metallurgical Processes from Applied Petrologic Viewpoints

  • Park, Won Choon
    • Economic and Environmental Geology
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    • v.11 no.3
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    • pp.89-98
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    • 1978
  • Mineralogy, beneficiation, and processes of titanium ores are reviewed from petrographic viewpoints. The most important titanium minerals are ilmenite ($FeTiO_3$) and rutile ($TiO_2$). Ilmenite will play major role :for raw material, because rutile are rapidly diminishing. Thus, there is a need to develope a successful process for producing high grade Ti02 from ilmenite. Commercial, as well as R and D processes to treat more abundant ilmenite ores fall in three general classess: 1. Iron in ilmenite is partially or completely reduced and separated either physically or chemically. 2. Iron is reduced to ferrous state and chemically leached away from the titanium. 3. Ore is treated to make chlorides either selectively or with subsequent separation and purification of $TiC_4$. Routes and efficiencies of these process technologies are primarily influenced by the particular ore deposit to be mined and secondly by environmental considerations. One deposit parameters which influence ilmenite process technologies are: 1. Complexity of microtextures of ilmenite intergrown with Fe-oxide minerals. 2. Composition of concentrates; ilmenites contain minor amounts of substituted Mg, Mn, and V. These elements plus iron and gangue minerals can cause difficulties to complete reactions, substantial acid consumption, difficulties of removing waste solids, and waste disposal problems. Major contributions to be made by petrologists for process optimization are: characterization and interpretation of compositional and physical changes of raw materials and solids derived from process streams. These informations can play significant role in selecting and improving process steps for titania production.

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Iron Extraction Characteristics of Sediment Samples from a River Bank Filtration Site (강변 여과 취수 지역 퇴적물의 철 화학종 추출 특성)

  • Hyun, Sung Pil;Moon, Hee Sun;Yoon, Pilsun;Kim, BoA;Ha, Kyoochul
    • Journal of the Mineralogical Society of Korea
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    • v.26 no.2
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    • pp.129-138
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    • 2013
  • River bank filtration has been considered as a promising alternative water management scheme, in which groundwater is extracted from an aquifer near a river after infiltration of the river water into the aquifer, thereby improving and maintaining the quality of water recovered. Iron (Fe) associated with sediment in contact with groundwater and infiltrating surface water is an important factor in determining the quality of water recovered from the pumping wells in river bank filtration. This study reports the results of Fe speciation in the aquifer sediment samples collected from different depths at the river bank filtration site in Changwon, studied using four different chemical extraction methods, namely, ferrozine, oxalate, HCl, and DCB methods. Overall, the results show that Fe(II) as well as the total Fe content decreases with depth down to ~20 m and then increases further below. This trend is consistent with the redox characteristics suggested by visual observation. The silt/clay size fraction (${\phi}$ < 62.5 ${\mu}M$) has up to 2~10 times more Fe compared with the sand size fraction (62.5 ${\mu}M$ < ${\phi}$ < 2 mm), depending on the extraction method. Of the four extraction methods, DCB solution extracted the most Fe from the sediment samples. The amounts of Fe extracted by the different extraction methods can be a good indicator of the redox conditions along the depth of the aquifer.