• Title/Summary/Keyword: Mineral grade

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Mineralogical Characteristics and Designation of Key Beds for the Effective Surveys of the Jeonnam Pyrophyllite Deposits (전남일원 납석광상의 광물학적 특성과 효과적 탐사를 위한 Key Beds의 선정)

  • Yoo, Jang-Han;Kim, Yong-Ug;Lee, Gill-Jae
    • Journal of the Mineralogical Society of Korea
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    • v.22 no.4
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    • pp.297-305
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    • 2009
  • Ores of the Jeonnam pyrophyllite province mainly consist of not only pyrophyllite but also kaolinite, and they usually contain minor amounts of muscovite and quartz. We usually call them as porcelaneous stones which usually show lower grade characteristics in the viewpoint of Korean nonmetallic industries. Mineralogical studies for the ores and their intimate formations revealed that another kind of clay minerals could have been produced from the volcanic sediments with similar ages and compositions. Corundum is commoner than the diaspore in the pyrophyllite deposits, and so diaspore can be regarded as one of temporary minerals from which corundum would be finally formed. Kaolinite deposits contain neither diaspore nor corundum, but alunites produced by an advanced argillic alteration are often observed in the upper portions of the kaolin ores. The lowest formation interbedded with pyrophyllite and/or kaolinite ores usually contain purple tuff bed on the uppermost part, and in ascending order, siliceous formation, fine ash tuff and lapillistone are found in the study areas. As ages are becoming younger, amounts of pyrophyllite and kaolinite are radically decreased, or disappeared completely. On the other hand, content of muscovite is slightly increased, and those of plagioclase feldspars and quartz are found to have been preserved from the original rocks during alteration process. Most of ore bodies show rather well bedded formations which are easily discernable in the outcrops, but more effective discremination is desirable where rather massive ores exist. Siliceous beds and purple tuff ones on the upper part of ore bodies would be useful as marker horizons or key beds which have distinct lithologies and extensions.

Environmental Geochemistry and Heavy Matel Contamination of Ground and Surface Water, Soil and Sediment at the Kongjujuil Mine Creek, Korea (공주제일광산 수계에 분포하는 지하수, 지표수, 토양 및 퇴적물의 환경지구화학적 특성과 중금속 오염)

  • 이찬희
    • Economic and Environmental Geology
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    • v.32 no.6
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    • pp.611-631
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    • 1999
  • Enviromental geochemisty and heary metal contamination at the Kongjueil mine creek were underaken on the basis of physicohemical properties and mineralogy for various kinds of water (surface, mine and ground water),soil, precipitate and sediment collected of April and December in 1998. Hydrgeochemical composition of the water samples are characterized by relatively significant enricant of Ca+Na, alkiali ions $NO_3$ and Cl inground and surfore water, wheras the mine waters are relatively eneripheral water of the mining creek have the characteristics of the (Ca+Mg)-$(HCO_3+SO_4)$type. The pH of the mine water is high acidity (3.24)and high EC (613$\mu$S/cm)compared with those of surface and ground water. The range of $\delta$D and $\delta^{18}O$ values (relative to SMOW) in the waters are shpwn in -50.2 to -61.6% and -7.0 to -8.6$\textperthousand$(d value=5.8 to 8.7). Using computer program, saturation index of albite, calcite, dolomite in mine water are nearly saturated. The gibbiste, kaolinite and smectite are superaturated in the surface and ground water, respectively. Calculated water-mineral reaction and stabilities suggest that weathing of silicate minerals may be stable kaolinite owing to the continuous water-rock reaction. Geochemical modeling showed that mostly toxic heavy metals may exist larfely in the from of metal-sulfate $(MSO_4\;^2)$and free metal $(M^{2+})$ in nmine water. These metals in the ground and surface water could be formed of $CO_3$ and OH complex ions. The average enrichment indices of water samples are 2.72 of the groundwater, 2.26 of the surface water and 14.15 of the acid mine water, normalizing by surface water composition at the non-mining creek, repectively. Characteristics of some major, minor and rate earth elements (Al/Na, K/Na, V/Ni, Cr/V, Ni/Co, La/Ce, Th/Yb, $La_N/Yb_N$, Co/Th, La/Sc and Sc/Th) in soil and sediment are revealed a narrow range and homogeneous compositions may be explained by acidic to intermediate igneous rocks. And these suggested that sediment source of host granitic gneiss colud be due to rocks of high grade metamorphism originated by sedimentary rocks. Maximum concentrations of environmentally toxic elements in sediment and soil are Fe=53.80 wt.% As=660, Cd=4, Cr=175, Cu=158, Mn=1010, Pb=2933, Sb=4 and Zn=3740 ppm, and extremely high concentrations are found are found in the subsurface soil near the ore dump and precipitates. Normalizing by composition of host granitic gneiss, the average enerichment indices are 3.72 of the sediments, 3.48 of the soils, 10.40 of the precipitates of acid mine drainage and 6.25 of the soils near the main adit. The level of enerichment was very severe in mining drainage sediments, while it was not so great in the soils. mineral composition of soil and sediment near the mining area were partly variable being composed of quartz, mica, feldspar, chlorite, vermiculite, bethierin and clay minerals. reddish variable being composed of quartz, mica, feldspar, chlorite, vermiculite, bethierin and clay minerals. Reddish brown precipitation mineral in the acid mine drainage identifies by schwertmanite. From the separated mineralgy, soil and sediment are composed of some pyrite, arsenopyite, chalcopyrite, sphalerite, galena, malachite, goethite and various kinds of hydroxied minerals.

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Strategy to Recover Rare Earth Elements from a Low Grade Resource via a Chemical Decomposition Method (화학적 분해법을 이용한 난용성 자원으로부터 희토류 회수 특성 연구)

  • Kim, Rina;Cho, Heechan;Jeong, Jinan;Kim, Jihye;Lee, Sugyeong
    • Resources Recycling
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    • v.29 no.1
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    • pp.17-24
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    • 2020
  • In this study, rare earth elements (REE) leaching from a refractory REE ore containing goethite as a major gangue mineral was conducted, introducing a two-stage method of chemical decomposition-acid leaching. At the chemical decomposition step, using one of alkaline agent, NaOH, the ore was decomposed, changing NaOH concentration from 20 to 50 wt% at 10% (w/w) of pulp density and the maximum temperature achieved without boiling at each NaOH concentration. With increasing NaOH concentration, light REE (Ce, La and Nd) and iron were concentrated in the solid phase which is the decomposed product, while aluminum (Al) and phosphorus (P) were removed to the liquid phase, and their concentrations in the solid phase were down to 0.96 and 0.17%, respectively. In addition, through XRD analysis, it was found that the crystallinity of goethite was considerably decreased. At the acid leaching step, the product decomposed by 50 wt% NaOH was leached at 3.0 M HCl and 80 ℃ for 3 hr, then the REE leaching efficiency was above 94% (Ce 80%), and the leaching efficiencies of Al and P were decreased to 12 and 0%, respectively. Therefore, in terms of both REE leaching efficiency and impurity removal, those decomposition and leaching conditions were chosen as optimum processing methods of the investigated material. In terms of REE leaching mechanism, because REE and iron leaching efficiencies showed the positive correlation each other, so it can be concluded that decreasing crystallinity of goethite affect the improvement of REE leaching.

A Study on the Various Noerok from Janggi-myeon, Pohang (포항 장기면 일대에 산출되는 뇌록의 다양성 연구)

  • Mun, Seong Woo;Kim, Jae Hwan;Kong, Dal-Yong;Moon, Dong Hyeok;Jeong, Hye Young
    • The Journal of the Petrological Society of Korea
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    • v.27 no.4
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    • pp.195-205
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    • 2018
  • Noerok is a green pigment made of mineral used the Gachil(priming coat) of wooden architecture in Chosun Dynasty era. It has been reported that various Noerok are discovered in Janggimyeon, Pohang. In this study, The Noerok from two places is compared and discussed. Noerok in the two places has blulsh-green to green color, and it is similar to their occurrences on fracture filling, vein and dike on outcrop. However, there are differences between two sites according to its petrological feature, mineral composition and geochemistry. While the Noeseongsan sample is mostly celadonite, Gwangjeongsan samples are characterized by celadonite with varying contents of cristobalite, tridymite, feldspar, along with some vitrified contents. In terms of major elements, the amount of $Al_2O_3$, $Fe_2O_3$, MgO and $K_2O$ decreases linearly with increasing $SiO_2$, whereas $Fe_2O_3$ is linearly proportional to MgO. In summary, Noerok in the study areas can be classified into 4 types (type 1, type 2, type 3-1, type 3-2) base on color, mineral composition, elemental composition, and vitrification grade.

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.

Basic Study for the Recycling of Phosphogypsum (인산부생석고(燐酸副生石膏)의 재활용(再活用)을 위한 기초연구(基礎硏究))

  • Park, Woon-Kyoung;Song, Young-Jun;Lee, Jung-Mi;Lee, Gye-Seung;Kim, Youn-Che;Shin, Kang-Ho;Yoon, Sin-Ae;Park, Charn-Hoon
    • Resources Recycling
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    • v.15 no.2 s.70
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    • pp.58-68
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    • 2006
  • This study is carried out for the purpose of investigating the property of phosphogypsum, and suggesting the proper recycling system for it. The chemical composition, mineralogical composition, particle size distribution and shape of phosphogypsum were investigated. The size distribution and constitution of impurities, distribution of heavy metals are also investigated. In conclusion, the grade and yield of recoverable phosphogypsum were discussed.

APPLICATION OF LIKELIHOOD RATIO MODEL FOR LANDSLIDE SUSCEPTIBILITY MAPPING USING GIS AT LAI CHAU, VIETNAM

  • LEE SARO;DAN NGUYEN TU
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.314-317
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    • 2004
  • The aim of this study was to evaluate the susceptibility from landslides in the Lai Chau region of Vietnam, using Geographic Information System (GIS) and remote sensing data, focusing on the relationship between tectonic fractures and landslides. Landslide locations were identified from an interpretation of aerial photographs and field surveys. Topographic and geological data and satellite images were collected, processed, and constructed into a spatial database using GIS data and image processing techniques, and a scheme of the tectonic fracturing of the crust in the Lai Chau region was established. In this scheme, Lai Chau was identified as a region with low crustal fractures, with the grade of tectonic fracture having a close relationship with landslide occurrence. The factors found to influence landslide occurrence were: topographic slope, topographic aspect, topographic curvature, distance from drainage, lithology, distance from a tectonic fracture and land cover. Landslide prone areas were analyzed and mapped using the landslide occurrence factors employing the probability-likelihood ratio method. The results of the analysis were verified using landslide location data, and these showed a satisfactory agreement between the hazard map and existing landslide location data.

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Quality Comparison of Commercial Boiled-dried Anchovies by Different Catch Methods

  • Kim Jin-Soo;Heu Min-Soo
    • Fisheries and Aquatic Sciences
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    • v.5 no.3
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    • pp.245-250
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    • 2002
  • This study was conducted to compare the quality among commercial boiled-dried anchovies caught by different methods. Regardless of catch methods, the moisture, salinity and acid-insoluble ash contents of commercial boiled-dried anchovies ranged from $23.2-25.2\%,\;6.8-7.4\%$. and $0.32-0.46\%$, respectively. By sensory evaluation, these anchovies were less than $5\%$ in break-age, whitish or yellowish in color and had a foul smell. Judging from the above results and Korean Standards (KS) for foods, these anchovies were classified into special grade. There was no difference in total amino acid content. While, in a major mineral content, boiled-dried anchovy caught by set net (BA-SN) was the highest, and those caught by lift net (BA-LN) and tow net (BA-TN) followed in order. The lipid oxidation progressed at the slowest rate in the BA-SN, and then no difference in the lipid oxidation was found between the BA-LN and BA-TN. Judging from the results of chemical analysis and sensory evaluation, the BA-TN was the worst quality among the commercial boiled-dried anchovies. No difference in quality was found between the BA-LN and the BA-SN.

Applications of High-Quality Base Oil to Specialty Lubricants

  • Moon, Woo-Sik
    • KSTLE International Journal
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    • v.3 no.1
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    • pp.30-37
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    • 2002
  • There have been significant improvements in base oil quality in order to satisfy recent market needs. In particular requirements of passenger car motor oils have been leading the trend. Now, high quality base oils such as VHVI base oils and PAOs are to be formulated in order to meet the tight volatility specifications. The severe hydrocracking, hydro-isomerized dewaxing and hydro-finishing process with noble-metal based catalysts (named UCO lube process) developed by SK corporation has been introduced as one of economic hydroprocessing routes to produce high quality VHVI base oils and food grade white mineral oils from fuels hydrocracker residue. Product quality of UCO lube process is similar to PAO in. general performances and therefore provides satisfactory performance far all straightforward applications in general lubricants. However, when applied to specialty lubricants like transformer oils, spray oils and coning oils, severely hydrocracked base oils are known to have various compatibility problems with gas or surfactants formulated in them. These problems are related to the difference in their composition; inherent high paraffin contents and lack of dissolving ability, Fortunately, it was found that excellent specialty lubricants could be made by carefully selecting and formulating adequate additives and/or aromatic compounds. Moreover, these specialties with high quality VHVI base oils ofter various advantages over conventional base oil based products.

Porosity and Electrical Resistivity of Formed Cokes Made from Anthracite and Phenolic resin (무연탄(無煙炭)과 페놀수지(樹脂)로부터 제조(製造)된 성형(成形)코크스의 기공율(氣孔率)과 전기저항율(電氣抵抗率))

  • Lee, Gye-Seung;Song, Young-Jun
    • Resources Recycling
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    • v.17 no.5
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    • pp.19-27
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    • 2008
  • In this study, the porosity and electrical resistivity of the formed coke produced by sintering the mixture of domestic anthracite and phenolic resin were mainly investigated, when the effect of the amount of binder, the hydration temperature and time, the hardening temperature and time, sintering temperature and time, the particle size of anthracite, the grade of anthracite, and the mixing ratio of phenolic resin on the physical properties of the coke were studied. As a result, It was found that the electrical resistivity and porosity of the formed coke are varied in the range of $0.3\sim1.2\Omega{\cdot}cm$ of $10\sim30%$, respectively, in accordance with the variation of factors.