• Economic and Environmental Geology
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• v.32 no.3
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• pp.227-236
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• 1999

The Daeyou pegmatite is located at the central westerm part of the peninsula. Geology of the mine area consists mainy of pre-Combrian granite gneiss and leucoratic gneiss which are intruded by Mesozoic granites. The pegmatite deposits occur within granite gneiss. Most of pegmatites contain quartz, perthite, microcline-perthite, microcline, sodic plagioclase and tourmaline as dominant minerals with accessory minerals of mica (muscovite, biotite, sericite)and pyrite. Tourmaline occurs as four types: 1) unaltered single crystals, 2) patially sericitized grains bordered by sericite assemblage, 3) tourmaline intergrown with feldspar and qurtz grains, and 4) tourmaline introduced veinlet/ On the basic of optical, X-ray diffraction and chemical analysis, the composition of tourmaline mostly falls on the schorl-elbaite join, in the composition of tourmaline mostly falls on the schorl-elbraite join, in the composition of schorl end member from 0 to about 50%. In spite of the different occurrences, chemical composition of tourmaline shows the limited ranges as follows: $SiO_{2}$ (34.53~35.01 wt.%), $Al_{2}O_{3}$ (33.58~34.26wt.%), FeO (13.73~14.17wt.%), $Na_{2}O$ (1.60~1.72wt.%), MgO (0.56~0.72wt.%), MnO (0.12~0.18wt.%), CaO (0.02~0.06wt.%), $K_{2}O$(0.02~0.03wt.%) $TiO_{2}$ (0.02~0.05wt.%) and $Cr_{2}O_{3}$ (0.02~0.03wt.%). K-Ar ages of the muscovite and sericite fall between 1010$\pm$15 and 1074$\pm$16Ma and between 161.56$\pm$3.09 and 161.67$\pm$Ma, respectivrly. This means that hydrothrmal alteration occurred during middle Jurassic, whereas the pegmatite was initally formed during the late proterozoic age.

• Journal of Environmental Science International
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• v.8 no.4
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• pp.491-496
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• 1999

Removal of Cu(II), Cr(III) and Pb(II) ions from aqueous solutions using the adsorption process on the loesses has been investigated. Variations of contact time, pH, adsorption isotherms and selectivity of coexisting ions were experimental parameters. pH of KJ and YIK samples diluted to 1% solution, was rearly the same with each value of pH 5.58 and 5.49, and both samples showed weak acidic properties. From chemical analysis, both samples contain remarkably different amounts of ${SiO}_{2}$, ${Al}_{2}O_{3}$ and ${Fe}_{2}O_{3}$. From XRD measurement, quartz was mainly observed in both samples. Kaolinite was also observed, also in both samples, but Feldspar was only observed in KJ sample. Adsorption of metal ions on the loesses were reached at equilibrium by shaking for about 30min. The adsorption of Cr(III) ion was higher than that of Cu(II) oand Pb(II) ions. The order of amount adsorbed among the investigated ions was Cr(III)>Pb(II)>Cu(II). In acidic solution, the adsorptivity of loesses was increased as pH increased. The adsorption of Cr(III) ion on the loesses were fitted to the Freundlich isotherms. Freundlich constants(1/n) of KJ and YIK loesses were 0.54 and 0.55, respectively.

• Economic and Environmental Geology
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• v.8 no.3
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• pp.135-146
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• 1975

The chiastolite bearing shale was known to occur in various coal fields in South Korea among which the Kangneung coal fields is the most outstanding in quality and quantity of chiastolite. The chiastolite occurs mostly in black shales of Sadong formation and little in shales of Hongjom and Kobangsan formations, and is most abundant in the footwall coaly shales of the Sadong coal seams. The chiastolite has been proved to be thermal contact product of the high aluminous shale that comes into contact with Kangneung granite. The distribution of chiastolite in the Kangneung coal field is irregular. The eastern part of the region contains more chiastolite than that of western part. It is believed that the difference of the grade is due to the intensity of metamorphism. The grade of chiastolite in the shale varies from few percent up to as high as 60 % in volume, and the minable reserve of the chiastolite is estimated about 4,700,000 tons. This reserves is rather concentrated in few localities such as in Jiam Mine, Jungrim Mine, Sir 1 Hang in the Whasung Mine, the second and third sections of Kangneung Mine and Umbuelri district. The chemical composition of chiastolite bearing coaly shale is $SiO_2$, 35.0%; $Al_2O_3$, 27.0%; $Fe_2O_3$, 0.29%.

• Journal of Soil and Groundwater Environment
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• v.14 no.6
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• pp.78-86
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• 2009

Applicability of CaO and steel slag as stabilizers in the treatment of field and paddy soils near Pungjeong mine contaminated with arsenic and cationic heavy metals was investigated from batch and column experiments. Immobilization of heavy metals was evaluated by TCLP dissolution test. Immobility of heavy metal ions was less than 15% when steel slag alone was used. This result suggests that $Fe_2O_3$ and $SiO_2$, known as the major component of steel slag, have little effect for the immobilization of heavy metal ions due to acidity of TCLP solution. Immobilization of cationic heavy metals was little affected by the ratio of CaO and steel slag while arsenic removal was increased as the ratio of steel slag to CaO increased. In the column test, concentrations of both arsenic and cationic heavy metals in effluents were below the water discharge guideline over the entire reaction period. This result can be explained by the immobilization of cationic heavy metals from the increased pH in soil solution as well as by the formation of insoluble $Ca_3(AsO_4)_2$. From this work, it is possible to suggest that arsenic and cationic heavy metals can be concurrently stabilized by application of both CaO and steel slag.

• Journal of Powder Materials
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• v.18 no.5
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• pp.430-436
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• 2011

Joining of NiO-YSZ to 316 stainless steel was carried out with B-Ni2 brazing alloy (3 wt% Fe, 4.5 wt% Si, 3.2 wt% B, 7 wt% Cr, Ni-balance, m.p. 971-$999^{\circ}C$) to seal the NiO-YSZ anode/316 stainless steel interconnect structure in a SOFC. In the present research, interfacial (chemical) reactions during brazing at the NiO-YSZ/316 stainless steel interconnect were enhanced by the two processing methods, a) addition of an electroless nickel plate to NiO-YSZ as a coating or b) deposition of titanium layer onto NiO-YSZ by magnetron plasma sputtering method, with process variables and procedures optimized during the pre-processing. Brazing was performed in a cold-wall vacuum furnace at $1080^{\circ}C$. Post-brazing interfacial morphologies between NiO-YSZ and 316 stainless steel were examined by SEM and EDS methods. The results indicate that B-Ni2 brazing filler alloy was fused fully during brazing and continuous interfacial layer formation depended on the method of pre-coating NiO-YSZ. The inter-diffusion of elements was promoted by titanium-deposition: the diffusion reaction thickness of the interfacial area was reduced to less than 5 ${\mu}m$ compared to 100 ${\mu}m$ for electroless nickel-deposited NiO-YSZ cermet.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.384-389
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• 2002

This study was aimed to evaluate the weldability and optimize the welding conditions for flash butt welding of 780MPa grade steel applied to the automotive bumper reinforcement. And then the relationship between the welding conditions and the joint performance relating specifically to coil-joining steel would be established. The effect of welding conditions between flashing and upsetting process was elucidated. Microstructure observation of the joint indicated that the decarburized band was mainly changed with upsetting process. Width of HAZ was also related to the upsetting conditions rather than the flashing conditions. Generally maximum hardness at HAZ was correlated with $C_{eq}$ of steel and the empirical relationship was obtained to estimate the HAZ properties. Tensile elongation at the joint was usually decreased with increasing the initial clamping distance. Investigation of fracture surface after tensile and bending tests reveal that the origin of cracking at the joint was oxide inclusions composed of $SiO_2$, MnO, $Al_2$ $O_3$, and/or FeO. The amount of inclusions was dependent on the composition ratio of Mn/Si in steel. If this ratio was above 4, the amount of inclusions was low and then the resistance to cracking at the joint was enough to maintain the joint performance. It was obtained that the flashing process influenced the conditions for the energy input to establish uniform or non-uniform molten layer, while the upsetting conditions influenced the joint strength. Heat input variable during flashing process was also discussed with the joint properties.

• Korean Journal of Heritage: History & Science
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• v.35
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• pp.160-184
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• 2002

The composition analysis of mural pigments at Daeungjeon Hall of Bongjeongsa Temple(Treasure No. 55) and ancient tomb with mural pigments in Goadong(Historic site No. 165) were carried out by XRF and MXRD. The analytical result showed that red pigments were Red Lead($Pb_3O_4$), Cinnabar(HgS) at Daeungjeon Hall of Bongjeongsa Temple and Cinnabar(HgS) in Goadong. The main composition identified in white pigments were Lead Carbonate Hydroxide[$PbCO_3{\cdot}Pb(OH)_2$]. Green pigments were basic copper chloride[Paratacamite $CuCl{\cdot}Cu(OH)_3$], celadonite[$K(Mg,Fe,Al)_2(Si, Al)_4O_{10}(OH)_2$] at Daeungjeon Hall of Bongjeongsa Temple and were basic copper chloride or basic copper carbonate in Goadong. Therefore it proved that mural pigments painted in use the mineral materials.

• The Journal of the Petrological Society of Korea
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• v.12 no.1
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• pp.32-52
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• 2003

The Mt. Baegyang in Busan, composed of sedimentary basement rocks (Icheonri Formation), andesite (lava), andesitic pyroclastic rocks, fallout tuff and tuffaceous sedimentary rocks, rhyolitic pyroclastic rocks, intrusive rocks (granite-porphyry, felsite, and biotite-granite) of Cretaceous age in ascending order. The volcanic rocks show a section of composite volcano which comprised alternation of andesitic lava and pyroclasitc rocks, rhyolitic pyrocalstic rocks (tuff breccia, lapilli tuff, fine tuff) from the lower to the upper strata. From the major element chemical analysis, the volcanic and intrusive rocks belong to calc-alkaline rock series. The trace element composition and REE patterns of volcanic and plutonic rocks, which are characterized by a high LILE/HFSE ratio and enrichments in LREE, suggest that they are typical of continental margin arc calc-alkaline rocks produced in the subduction environment. Primary basaltic magma might have been derived from partial melting of mantle wedge in the upper mantle under destructive plate margin. Crystallization differentiation of the basaltic magma would have produced the calc-alkaline andesitic magma. And the felsic rhyolitic magma seems to have been evolved from andesitic magma with crystallization differentiation of plagioclase, pyroxene, and hornblende.

• Korean Journal of Materials Research
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• v.11 no.5
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• pp.367-371
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• 2001

In this paper, theS $r_2$(T $a_{1-x}$ , N $b_{x}$)$_2$ $O_{7}$(STNO) films among ferroelectric materials having a low dielectric constant for metal-ferroelectric-semiconductor field effect transistor(MFS-FET) were discussed. The STNO thin films were deposited on p-type Si(100) at room temperature by co-sputtering with S $r_2$N $b_2$ $O_{7(SNO)}$ ceramic target and T $a_2$ $O_{5}$ ceramic target. The composition of STNO thin films was varied by adjusting the power ratios of SNO target and T $a_2$ $O_{5}$ target. The STNO films were annealed at 8$50^{\circ}C$, 90$0^{\circ}C$ and 9$50^{\circ}C$ temperature in oxygen ambient for 1 hour. The value of x has significantly influenced the structure and electrical properties of the STNO films. In the case of x= 0.4, the crystallinity of the STNO films annealed at 9$50^{\circ}C$ was observed well and the memory windows of the Pt/STNO/Si structure were 0.5-8.3 V at applied voltage of 3-9 V and leakage current density was 7.9$\times$10$_{08}$A/$\textrm{cm}^2$ at applied voltage of -5V.of -5V.V.V.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.4
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• pp.438-446
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• 2006

A lab-scale batch test was conducted to develop capping materials to reduce the sediment phosphorus in the stagnant water zone of Gyeongancheon in Paldang Lake. The mean grain size(Mz) of sediment in the investigated area was 7.7 ${\phi}$, which is very fine, and the contents of organic carbon($C_{org}$) was 2.4%, which is very high. For the phosphorous release experiment to select the optimal capping material, sand layer, powder-gypsum($CaSO_4{\cdot}2H_2O$), granule-gypsum, complex layer(gypsum+sand) and the control were compared and evaluated in the 150 L reactor for 45 days. In case of the capping with the sand, it was found that the phosphorous from the sediment could be reduced by around 50%. However, it was found that this caused the reduction of the dissolved oxygen in the water column(by less than 3 mg/L) due to the resuspension of sediment and the organic matter decomposition that comes from the generation of $CH_4$ gas in the 1 cm of the sand layer. Therefore, it is likely that the sand layer has to be thickener in case of the sand capping. Powder-gypsum and granule-Gypsum reduced phosphorous release by more than 80%. However, the concentration of ${SO_4}^{2-}$ in the water column increased, making it difficult to apply it to the drinking water protection zone. We developed Fe-Gypsum and $SiO_2$-gypsum materials to reduce the solubility of ${SO_4}^{2-}$. Powder-Gypsum creates the interception film that does not have any aperture on the sediment layer when it is combined with the water. However phosphorous release caused by the generation of $CH_4$ gas may happen at a time when the gypsum layer has the crack. Capping through the complex layer(granule-Gypsum+sand(1 cm)) found to be suitable for the drinking water protection zone because it was effective to prevent phosphorus release. Moreover, this leads to the lower solubility from the concentration of ${SO_4}^{2-}$ into the water column than the powder-Gypsum and granule-Gypsum. The addition of gypsum($CaSO_4{\cdot}2H_2O$) into the sediment can reduce the progress of methanogensis because fast early diagenesis and sufficient supply of ${SO_4}^{2-}$ to the sediment, stimulate the SRB(sulfate reducing bacteria) highly.