• Bulletin of the Korean Chemical Society
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• v.12 no.5
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• pp.520-524
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• 1991

Stainless steel 304 2B and BA are oxidized in 2.5 M $CrO_3/$ 5.0 M $H_2SO_4$ solution, and elemental composition and oxidized state of the surface region is analyzed as a function of the surface depth using X-ray photoelectron spectroscopy. It is found that Fe and Cr are preferentially oxidized and diffuse outward following the oxidation. Element Ni, the third major component of the steel is not oxidized and remains deep under the surface. It is also found that the oxidized Fe dissolves considerably into the solution thereby enriching the gas-oxide interface with Cr.

• Economic and Environmental Geology
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• v.12 no.4
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• pp.181-195
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• 1979

The Nambu orebodies of the Okbang tungsten mine are hosted in the Precambrian amphibolite and Weonnam formation. These orebodies can be classified into two types; The scheelite-bearing ore vein occurring in the amphibolite (the Nambu 1, 2 adits) and tungsten-bearing quartz vein along the contact between the amphibolite and the Weonnam formation (the Young-ho, -1, -2, -3 levels). The scheelite-bearing ore vein in the amphilbolite is discontinuous, narrow, and highly irregular in geometry, occurring only within the amphibolite with which of the vein is graduational. Based on these feature of the mode of occurrence, the origin of this ore type might be attributed to a potential segregation of tungsten ore fluid in situ from hornblenditic basic magma of the host rock. Tungsten-bearing quartz vein, however, is considered to have deposited along the N30-60E trending fractures as a later hypothermal vein after the hornblendite was emplaced. The principal ore mineral is scheelite with minor amount of wolframite, and the gangue minerals are quartz, and small amounts of fluorite, pyrrhotite, chalcopyrite and calcite. Fluid inclusion study of minerals from the Nambu orebody reveals that the fluids in fluorite of the scheelite-bearning ore vein attained a temperature range of $208{\sim}256^{\circ}C$ and those in quartz from the tungsten-bearing quartz vein a temperature range of $220{\sim}357^{\circ}C$. The real formation temperatures can be somewhat higher than filling temperatures, if pressure correction is made. Chemical analysis of 8 amphibolitc samples on major and some trace elements indicate that the amphibolite is igneous origin. On a Niggli diagram (al-alk)versus c, the analytical values are plotted on an igneous field, and on a Niggli diagram mg versus c they follow a karroo igneous trend line. According to the Ba, Cr, and Ni versus Niggli mg plots suggested by Leake (1964), Okbang amphibolite fall outside a pelitic field and compare favorably with his plots form ortho-amphibolites. Analitical values of $MoO_3$ of 8 samples of scheelite minerals from the Nambu orebody indicate that the tungsten-bearing quartz vein (type n) of Nambu orebody shows a range from 1. 69% to 4.38% which is higher than 0.94%~3.25% $MoO_3$ for the scheelite-bearing ore vein (type I). This fact indicates that the type II was deposited in a lower $fO_2/higher$ $fO_2$ environment and under lower temperature than the type I. Analysis of major components $WO_3$, MnO, and FeO of 6 samples of wolframite from the type II veins revealed that they contain 73.35~76.2% $WO_3$, 7.94~11.63% MnO, and 10.53~14.82% FeO. MnO/FeO ratios of wolframite shows the range of 0.85~1.17 which suggests a slightly higher temperature type of deposits than other major tungsten deposits in the country.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.2
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• pp.83-100
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• 2022

The Zhenzigou Pb-Zn deposit, which is one of the largest Pb-Zn deposit in the northeast of China, is located at the Qingchengzi mineral field in Jiao Liao Ji belt. The geology of this deposit consists of Archean granulite, Paleoproterozoinc migmatitic granite, Paleo-Mesoproterozoic sodic granite, Paleoproterozoic Liaohe group, Mesozoic diorite and Mesozoic monzoritic granite. The Zhenzigou deposit which is a strata bound SEDEX or SEDEX type deposit occurs as layer ore and vein ore in Langzishan formation and Dashiqiao formation of the Paleoproterozoic Liaohe group. White mica from this deposit are occured only in layer ore and are classified four type (Type I : weak alteration (clastic dolomitic marble), Type II : strong alteration (dolomitic clastic rock), Type III : layer ore (dolomitic clastic rock), Type IV : layer ore (clastic dolomitic marble)). Type I white mica in weak alteration zone is associated with dolomite that is formed by dolomitization of hydrothermal metasomatism. Type II white mica in strong alteration zone is associated with dolomite, ankerite, quartz and alteration of K-feldspar by hydrothermal metasomatism. Type III white mica in layer ore is associated with dolomite, ankerite, calcite, quartz and alteration of K-feldspar by hydrothermal metasomatism. And type IV white mica in layer ore is associated with dolomite, quartz and alteration of K-feldspar by hydrothermal metasomatism. The structural formulars of white micas are determined to be (K_0.92-0.80Na_0.01-0.00Ca_0.02-0.01Ba_0.00Sr_0.01-0.00)_0.95-0.83(Al_1.72-1.57Mg_0.33-0.20Fe_0.01-0.00Mn_0.00Ti_0.02-0.00Cr_0.01-0.00V_0.00Sb_0.02-0.00Ni_0.00Co_0.02-0.00)_1.99-1.90(Si_3.40-3.29Al_0.71-0.60)_4.00O₁₀(OH_2.00-1.83F_0.17-0.00)_2.00, (K_1.03-0.84Na_0.03-0.00Ca_0.08-0.00Ba_0.00Sr_0.01-0.00)_1.08-0.85(Al_1.85-1.65Mg_0.20-0.06Fe_0.10-0.03Mn_0.00Ti_0.05-0.00Cr_0.03-0.00V_0.01-0.00Sb_0.02-0.00Ni_0.00Co_0.03-0.00)_1.99-1.93(Si_3.28-2.99Al_1.01-0.72)_4.00O₁₀(OH_1.96-1.90F_0.10-0.04)_2.00, (K_1.06-0.90Na_0.01-0.00Ca_0.01-0.00Ba_0.00Sr_0.02-0.01)_1.10-0.93(Al_1.93-1.64Mg_0.19-0.00Fe_0.12-0.01Mn_0.00Ti_0.01-0.00Cr_0.01-0.00V_0.00Sb_0.00Ni_0.00Co_0.05-0.01)_2.01-1.94(Si_3.32-2.96Al_1.04-0.68)_4.00O₁₀(OH_2.00-1.91F_0.09-0.00)_2.00 and (K_0.91-0.83Na_0.02-0.01Ca_0.02-0.00Ba_0.01-0.00Sr_0.00)_0.93-0.83(Al_1.84-1.67Mg_0.15-0.08Fe_0.07-0.02Mn_0.00Ti_0.04-0.00Cr_0.06-0.00V_0.02-0.00Sb_0.02-0.01Ni_0.00Co_0.00)_2.00-1.92(Si_3.27-3.16Al_0.84-0.73)_4.00O₁₀(OH_1.97-1.88F_0.12-0.03)_2.00, respectively. It indicated that white mica of from the Zhenzigou deposit has less K, Na and Ca, and more Si than theoretical dioctahedral mica. Compositional variations in white mica from the Zhenzigou deposit are caused by phengitic or Tschermark substitution [(Al³⁺)^VI+(Al³⁺)^IV <-> (Fe²⁺ or Mg²⁺)^VI+(Si⁴⁺)^IV] substitution. It means that the Fe in white mica exists as Fe²⁺ and Fe³⁺, but mainly as Fe²⁺. Therefore, white mica from layer ore of the Zhenzigou deposit was formed in the process of remelting and re-precipitation of pre-existed minerals by hydrothermal metasomatism origined metamorphism (greenschist facies) associated with Paleoproterozoic intrusion. And compositional variations in white mica from the Zhenzigou deposit are caused by phengitic or Tschermark substitution [(Al³⁺)^VI+(Al³⁺)^IV <-> (Fe²⁺ or Mg²⁺)^VI+(Si⁴⁺)^IV] substitution during hydrothermal metasomatism depending on wallrock type, alteration degree and ore/gangue mineral occurrence frequency.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.2
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• pp.95-106
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• 2021

The SO₄ in the jarosite structure can be substituted by other oxyanions, and therefore, the transition of jarosite to goethite plays a very important role in controlling the behavior of oxyanions. In this study, the phase change according to the species of the oxyanion in jarosite and the related behavior of the oxyanion was studied by mineralogical and geochemical methods when jarosite, which is coprecipitated with various oxynions, undergoes a phase change by a reductive dissolution. Jarosite substituted by five oxyanions by 5 mol% was used in this study. The mineral phase change induced by reductive dissolution using ammonium oxalate was investigated, and the order of phase transition rate of jarosite to goethite was MoO₄-jarosite ≥ SeO₄-jarosite ≥ CrO₄-jarosite > pure jarosite > SeO₃-jarosite > AsO₄-jarosite, showing that the transition rates vary depending on the substituted oxyanion. The resultant concentration of the leached Fe was slightly different depending on the type of oxyanion and time but did not show a noticeable difference. The concentration of each oxyanion leached according to the change of the mineral phase showed that the order of concentration of oxyanions was Mo > Se(SeO₃) > As > Se(SeO₄) > Cr in general, and showed a slight increase with time. This trend was related to the species of oxyanions rather than mineral phase change. The results of this study showed that the phase transition of jarosite to goethite was affected by the species of oxyanions, but this tendency did not affect the concentrations leached oxyanions.

• Journal of Environmental Science International
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• v.8 no.6
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• pp.685-690
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• 1999

The pollution characteristics of groundwaters in Taegu City and correlation coefficients(r) between water pollution indicators were investigated for two years from January 1996 to December 1997. Volatile organic compounds such as TCE(tri-chloroethylene), PCE(tetrachloroethylene), l,l,l-trichloroethane, THM(trihalo-methane), dichloromethane, pesticides such as diazinon, parathion, malathion, and toxic inoganic matters such as As, Hg, Se, Pb, Cd, $Cr_6^+,$ CN were not detected in the groundwaters. Mean values of groundwater pollution indicators were below drinking-water standards, but hardness, $KMnO_4-C(potassium$ permanganate consumption), evaporate residues, $SO_4^{-2},\;Fe,\;NO_3^{-}-N,$ color and turbidity exceeded a little in some samples. As groundwater became deeper, hardness and evaporate residues remarkably increased, but $KMnO_4-C,\;NO_3^{-}-N,\;Cl-,$ color, turbity and bacteria decreased. $KMnO_4-C,$ evaporate residues, $Cl^-\;and\;SO_4^{-2}$ were very high at industrial and commercial areas, and $NO_3^--N$ and $NH_4^+-N$ were very high at agricultural and forest areas. It showed high positive significances in the relationships between hardness and each of evaporate residues, $SO_4^{-2}$, Zn and Mn, $KMnO_4-C$ and each of color, turbidity and Zn, color and each of turbidity, Cu, Zn and Mn, turbidity and each of Fe, Cu, Zn and Mn, and evaporate residues and each of $Cl^-,\;SO_4^{-2}$ and Zn.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.3
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• pp.598-605
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• 2001

The study that has been conducted is the consideration of the durability of dye, antibacterial activity, and deodorizing effects of cotton and silk textiles dyed with a botanical dying material that has been used in various ways over the years as Korean diet and folk remedies, the pomegranate. 1. The results of the K/S value of dying according to the types of mordants of textiles dyed with pomegranate extract the following have been discovered: The increase of K/S value of dying of the silk textiles appear to be higher than that of the cotton textiles. Next, silk textiles that have been treated with FeSO$_4$.7$H_2O$ appear to be at the highest. 2. The results of the color change measurement show a difference of color can be noticed according to the types of mordant. As opposed to those textiles that had been only scured textiles, all of the dyed textiles appeared to turn yellow. 3. Textiles that had been treated with $K_2$Cr$_2$O(sub)7 recorded the highest durability according to the colorfastness to light results. In the case of the cotton textiles colorfastness to washing, all appeared to show exceptional results of 3rd class or higher, excluding the textiles that had been treated FeSO$_4$.7$H_2O$. However silk textiles recorded relatively low classes of below 3rd to 4th class. For the colorfastness to washing of pollution, the results for both the cotton and silk textiles were excellent at class 4-5. The results of colorfastness to perspiration, colorfastness to rubbing, and colorfastness to dry cleaning showed comparatively exceptional results of 3rd to 4th class or higher when it came to dyed textiles. 4. According to the measurements of antibiosis, dyed textiles that had been treated with SnCl$_2$.2$H_2O$ appeared to show an exceptional bacterium decrease of approximately 70%. 5. According to the deodorizing measurements, dyed silk textiles appeared to have a higher deodorizing effect than cotton textiles. As for cotton textiles, those that had been treated with FeSO$_4$.7$H_2O$ and in the case of dyed silk textiles those that had been treated SnCl$_2$.2$H_2O$ recorded the highest deodorizing effect.

• 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 Korean Society of Forest Science
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• v.86 no.3
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• pp.324-333
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• 1997

The research has been made for the effects of the pollution by the abandoned coal mine drainage on the physical and chemical properties of soil, stream sediment and soil water. The soils overspreaded by the abandoned coal don't develop solum and the bulk density is $1.83g/m^3$, compared with $1.14-1.38g/m^3$ in the other forest soils. The soil pH range in coal bearing region ie, from 4.01 to 4.11 and non-coal bearing soil range is from 5.03 to 5.13. Heavy metals such as As, Cr, Ni, Mo and Ba of coal bearing soils and polluted stream sediments have larger concentration than those of non-coal content and non-polluted. Especially As and Mo concentrations are largely high in coal bearing. The relative ratios $K_2O/Na_2O$ of geochemical elements are higher in coal bearing soil and polluted stream sediments than those of non-coal bearing soils and non-polluted stream sediments as well as black shales of the Changri Formation. However, $MgO+Fe_2O_3+TiO_2/CaO+K_2O$ are the opposite trends, so that the ratios are lower in the polluted regions. The soil water pHs in the polluted regions are the strong acid(pH3.4-4.2) and buffer capacity of the polluted soil is low because canons such as $Na^+$, $K^+$, $Mg^{+2}$are leached by the acidification.

• Clean Technology
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• v.20 no.2
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• pp.108-115
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• 2014

Various metal chlorides and acid catalysts in ionic liquid solvent were investigated to directly convert cellulose into 5-hydroxymethylfurfural (5-HMF). Metal chlorides containing Sn(II), Zn(II), Al(III), Fe(III), Cu(II), and Cr(III) were used and acidic ionic liquid immobilized on silica gel as an acid catalyst and commercial acid catalysts (sulfuric acid, chloric acid, Amberlyst-15,DOWEX50x8) were used for comparison studies. The acid strength and amount of acid catalysts were probed with Hammett indicator. The selectivity and yield of 5-HMF were determined with reaction temperature, reaction time and catalyst ratio. A catalyst containing $CrCl_3-6H_2O$ and $SiO_2-[ASBI]HSO_4$ showed the highest selectivity and it was found that this catalyst had higher activity than commercial solid acid catalysts such as Amberlyst-15 and DOWEX50x8. The selectivity of 5-HMF appeared to be mainly dependent on the acid strength and catalyst ratio, it was found that levulinic acid was produced from 5-HMF by rehydration.

• Journal of the Korean Society of Costume
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• v.39
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• pp.79-89
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• 1998

This study was carried out the effect of stability and color extract for it's condition in the curcuma L.. dyeing. The stability is to investigate the absorbance of the curcumin, one of the major yellow pigments and the stability regarding the effect of light, oxygen temperature and pH. The dyeing condition is compared the effect of mordanting condition and the best way to extract pigment and analysed through the color-fastness rating, color-difference value test. The main results obtained are summarized as follows ; 1.The best and proper solvent to extrect curcumin pigment was a ethanol and a distilled water. 2. The light effect indicated that the absorbances of solution in absence of ligh was more stable. 3. The oxygen(O2) effect to curcumin show-ed that the condition in the absence of O2 was more stable than that in presence of O2 4. The temperature showed that the absorbnace was best stable in4$^{\circ}C$ and less changed at $25^{\circ}C$ 5. The curcumin-etanol solution was stable in pH 2~4. 6. Generally color-fastness rating to silk, wool and cotton indicated that crocking C.F. and perspiration C.F. were more than 3rd grade and dry cleaning C.F. was more than 4th grade. But light color-fastness and washing color-fastness were very poor. 7. To make good color fastness, the mordan-ting treated group and the pre-mordant conditions were more effective than others 8. When compared with color-difference value test indicated that the silk was looks like more reddish and bluish color and than the wool and cotton were greenish and bluish. As a mordant, A(C2H4OH(COOH3) and D(K2Cr2O7)were more effective to make green-ish color in the silk and the reddish color was abtained by B(Al.K(SO4)2.12H2O) and C(FeSO4.7H2O).