• Journal of Conservation Science
• /
• v.8 no.1 s.11
• /
• pp.10-15
• /
• 1999

The chemical compositions and microstructure of the punch'ong excavated from Bokwangri, Kangnung were investigated by the scanning electron microscope (SEM) with an energy dispersive X-ray spectrometer (EDS), X-ray diffractometer (XRD), and dilatometer. The compositions of body were $SiO_2(73-78\%),\;Al_2O_3(13-16\%)$, $RO{\cdot}R_2O(4-5\%,\;R=Ca,\;Mg,\;Na,\;K),\;R_xO_y(3-6\%,\;R=Fe,Ti)$ in weight ratio, which were higher silica and flux $(RO{\cdot}R_2O)$ but lower alumina. Owing to the high content$(21-30\%)$ of calcium oxide the glaze is considered lime type. Firing temperature range for the ceramic was presumed to about $1150^{\circ}C$.

• The Journal of Engineering Geology
• /
• v.13 no.4
• /
• pp.429-444
• /
• 2003

Domestic marbles are mostly distributed in Gyeonggi and Yeongnam Massifs, southwest and northeast Ogcheon Belts, which belong to Precambrian, age-unknown, Cambrian-Ordovician ages, respectively. The former marbles occur as interbedded rocks in metasediments and xenoliths in granitic gneisses. Age-unknown ones occur as interbedded in the formations of Hyangsanri, Gyeomyeongsan, Hwajeonri and Munjuri, and some in metasedimentary rocks. The latter ones occur as interbedded in Pungchon Limestone, and in Jeongseon Limestone, Hwacheonri Formation and Great Limestone Group, respectively. Among physical properties, porosity shows irregular patterns to density and compressive strength, respectively. Absorption ratio has a linear pattern of positive trend to porosity, and compressive strength mostly shows a positive trend to tensile strength. Compressive strengths of the marbles are as follows : Precambrian $1,106{\;}kg/\textrm{cm}^2$, age-unknown $935{\;}kg/\textrm{cm}^2$. Cambrian $1,162{\;}kg/\textrm{cm}^2$ and Ordovician $1,560{\;}kg/\textrm{cm}^2$, respectively. Tensile strengths have decreasing trends as the above order of geologic age. In diagrams of major elements, $Al_2O_3,{\;}Fe_2O_{3(t)}{\;}and{\;}Na_2O+K_2O$ generally show positive trends with increasing $v_2$. MgO/CaO of Precambrian and age-unknown marbles have much higher values than Cambrian and Ordovician marbles as follows, Precambrian 0.31, age-unknown 0.30, Cambrian 0.03 and Ordovician 0.08. And MgO shows a negative trend with increasing CaO, which nay be caused by dolomitization. By MgO contents they can be classified into calcitic dolomite, dolomitic limestone, limestone and dolomitic limestone, respectively.

• Economic and Environmental Geology
• /
• v.45 no.6
• /
• pp.643-659
• /
• 2012

The Chungju Fe-REE deposit is located in the Kyemyeongsan Formation of the Ogcheon Group. The Kyemyeongsan Formation includes meta-volcanic rocks and pegmatite hosted REE deposit which show different kind of REE-containing minerals. The meta-volcanic rocks hosted REE deposits' main REE minerals are allanite, zircon, apatite, and sphene, whereas the pegmatite hosted REE deposits is mainly composed of fergusonite, and karnasurtite, zircon, thorite. The meta-volcanic rock hosted major REE mineral is allanite as the form of aggregation and contains 23.89-29.19 wt% TREO (Total Rare Earth Oxide), 4.71-9.92 wt% $La_2O_3$, 11.30-14.33 wt% $Ce_2O_3$, 0.11-0.29 wt% $Y_2O_3$, 0.15-0.94 wt% $ThO_2$, as a formula of (Ca, Y, REE, Th)$_{2.095}$(Mg, Al, Ti, Mn, $Fe^{3+})_{2.770}(SiO_4)_{2.975}(OH)$. Accompanying REE in a coupled substitution for $Ca^{2+}$ (M1 site) and $Al^{3+}-Fe^{2+}$ (M2 site) leads to a large chemical variety. Due to the allanite's high contents of Fe, it belongs to Ferrialanite. The pegmatite hosted deposit's domi-nant REE mineral is fergusonite as prismatic or subhedral grains associated with zircon, fluorite and karnasurtite. Geochemical composition of the fergusonite($YNbO_4$) suggests substitution of Y-REE and Y-Th in A-site, and Nb-Ta-Ti in B-site, furthermore the proportion of $Y_2O_3$ and $Nb_2O_5$ is oddly 1:1.5 comparing to the ideal ratio 1:1 and Nb is higher than Y, also A-site Y actively substitutes with REE. Karnasurtite in pegmatite variously ranges 9.16-22.88 wt% $Ce_2O_3$, 2.15-9.16 wt% and $La_2O_3$, 0.44-10.8 wt% $ThO_2$, as a calculated formula (Y, REE, Th, K, Na, Ca)$_{1.478}(Ti, Nb)_{1.304}$(Mg, Al, Mn, $Fe^{3+})_{0.988}$(Si, P)$_{1.431}O_7(OH)_4{\cdot}3H_2O$. Firstly the 870-860 Ma is the initial age of the supercontinent Rhodinia dispersal and subsequent A-1 type volcanism, which contains Fe, REE, and HFS(High Field Strength elements; Nb, Zr, Y etc.) elements in Fe-rich meta-volcanic rocks dominant Kyemyeongsan Formation, might mineralized allanite. Another synthesis is that regional metamorphism at late Paleozoic 300-280 Ma(Cho et al., 2002) might cause allanite mineralization. Also pegmatite REE mineralization highly related to the granite intrusion over the Chungju area in Jurassic(190 Ma; Koh et al., 2012). Otherwise above all, A-1 type volcanism at the same time of the Kyemyeongsan Formation development, regional metamorphism and pegmatite, might have caused REE mineralization. Although REE ore bodies display a close spatial association, each ore bodies display temporal distinction, different mineral assemblage and environment of ore formation.

• Korean Chemical Engineering Research
• /
• v.52 no.5
• /
• pp.638-646
• /
• 2014

The effect of in-organic chelating agents with Fe(II) and Fe(III) in modified Fenton was evaluated to degradation BTEX (benzene, toluene, ethylbenzene, xylene). Citric acid and pyrophosphate were used in experimentals and an optimum chelating agent for BTEX degradation was determined. In $H_2O_2$/Fe(III)/citric acid, degradation of BTEX was decreased when concentration of citric acid was increased. In $H_2O_2$/Fe(III)/pyrophosphate, degradation of BTEX was increased when concentration of pyrophosphate was increased and degradation for BTEX was relatively high compared with $H_2O_2$/Fe(III)/citric acid. In $H_2O_2$/Fe(II)/chelating agents, degradation for BTEX was high and pH variation was minimized when molar ratio of Fe(II) and citric acid was 1:1. Optimum molar concentration of Fe(II), citric acid and $H_2O_2$ were 7 mM, 7mM and 500 mM for degradation of 100 mg/L of benzene to obtain best efficiency of $H_2O_2$, least precipitation of iron and best degradation.

• Journal of Korean Society on Water Environment
• /
• v.21 no.3
• /
• pp.284-288
• /
• 2005

In this study, photochemical advanced oxidation processes (AOPs) utilizing the Photo Fenton reaction ($Fe^{2+}+H_2O_2+UV$) were investigated in lab-scale experiments for the treatment of livestock wastewater. For the experimets, the livestock wastewater was pretreated by coagulation with $3,000mg/L\;FeCl_3$. The optimal conditions for Photo-Fenton processes were determined: pH was 5, the concentration of ferrous ion (Fe II) was 0.01 M. The concentration of hydrogen peroxide was 0.1 M, and molar ratio ($Fe^{2+}/H_2O_2$) was 0.1. The optimal reaction time was 80 min. Under the optimal condition of Photo-Fenton process, chemical oxygen demand (COD), color and fecal coliform removal efficiencies were about 79, 70, and 99.4%, respectively and sludge production was 7.5 mL from 100 mL of solution.

• The Journal of the Petrological Society of Korea
• /
• v.26 no.3
• /
• pp.271-280
• /
• 2017

The Dongcheondong granite is alkali feldspar granite in Dongcheondong, Gyeongju. The granite is coarse grained and consists of alkali feldspar, quartz, amphibole, and biotite. Alkali feldspar is perthitic orthoclase and quartz often shows undulatory extinction. Plagioclase often shows albite twins, and biotite and amphibole emplace as interstitial minerals. The Dongcheondong granite is plotted in A-type area having high ($Na_2O+K_2O)/Al_2O_3$ and low (MgO+CaO)/FeOT ratio. The Dongcheondong A-type granite has higher $SiO_2$, $Na_2O$, $K_2O$, Zr, Y, and REE contents (except for Eu) and lower $TiO_2$, $Al_2O_3$, CaO, MgO, Sr, Ba, and Eu contents than I-type granites in Gyeongsang Basin. These results show that the geochemical characteristics of the Dongcheondong A-type granite are distinguished from I-type granite in Gyeongsang Basin. A-type granite in the Dongcheondong is thought to has been generated by partial melting of I-type tonalite or granodiorite.

• Korean Journal of Environmental Agriculture
• /
• v.19 no.5
• /
• pp.401-418
• /
• 2000

1. Production of the artificial zeolite from coal ash Coal fly ash is mainly composed of several oxides including $SiO_2$ and $Al_2O_3$ derived from inorganic compounds remained after burning. As minor components, $Fe_2O_3$ and oxides of Mg, Ca, P, Ti (trace) are also contained in the ash. These components are presented as glass form resulting from fusion in the process of the combustion of coal. In other word, coal ash may refer to a kind of aluminosilicate glass that is known to easily change to zeolite-like materials by hydrothermal reaction. Lots of hot seawater is disposing near thermal power plants after cooling turbine generator periodically. Using seawater in the hydrothermal reaction caused to produce low price artificial zeolite by reduction of sodium hydroxide consumption, heating energy and water cost. As coal ash were reacted hydrothermally, peaks of quartz and mullite in the ash were weakened and disappeared, and new Na-Pl peaks were appeared strengthily. Si-O-Si bonding of the bituminous coal ash was changed to Si-O-Al (and $Fe^{3+}$) bonding by the reaction. Therefore the produced Na-Pl type zeolite had high CEC of 276.7 $cmol^+{\cdot}kg^{-1}$ and well developed molecular sieve structure with low concentration of heavy metals. 2. Utilization of the artificial zeolite in agro-environment The artificial zeolite(1g) could remove 123.5 mg of zinc, 164.7 mg copper, 184.4 mg cadmium and 350.6 mg lead in the synthetic wastewater. The removability is higher 2.8 times in zinc, 3.3 times in copper, 4.7 times in cadmium and 4.8 times in lead than natural zeolite and charcoal powder. When the heavy metals were treated at the ratio of 150 $kg{\cdot}ha^{-1}$ to the rice plant, various growth inhibition were observed; brownish discoloration and death of leaf sheath, growth inhibition in culm length, number of panicles and grains, grain ripening and rice yield. But these growth inhibition was greatly alleviated by the application of artificial zeolite, therefore, rice yield increased $1.1{\sim}3.2$ times according to the metal kind. In addition, the concentration of heavy metals in the brown rice also lowered by $27{\sim}75%$. Artificial Granular Zeolites (AGZ) was developed for the purification of wastewater. Canon exchange capacity was 126.8 $cmol^+{\cdot}kg^{-1}$. AGZ had Na-Pl peaks mainly with some minor $C_3S$ peaks in X-ray diffractogram. In addition, AGZs had various pore structure that may be adhere the suspended solid and offer microbiological niche to decompose organic pollutants. AGZ could remove ammonium, orthophosphate and heavy metals simultaneously. Mixing ratio of artificial zeolite in AGZs was related positively with removal efficiency of $NH_4\;^+$ and negatively with that of $PO_4\;^{3-}$. Root growth of rice seedling was inhibited severely in the mine wastewater because of strong acidity and high concentration of heavy metals. As AGZ(1 kg) stayed in the wastewater(100L) for 4days, water quality turned into safely for agricultural usage and rice seedlings grew normally.

• Korean Journal of Soil Science and Fertilizer
• /
• v.50 no.2
• /
• pp.127-134
• /
• 2017

Bottom ash (BA) has different macro- and micronutrients such as B, Mo, Fe, Ca, and Mg, providing useful resources for plant growth and soil quality. The objective of this study was to evaluate the applicability of artificial top-soil treated with BA in park area as a vegetation base material, especially for turfgrass growth. Collected BA was mixed with peat moss and clay at the ratio of 70:10:20 (w/w). In order to evaluate the park quality and turfgrass growth in park area, the artificial soil was applied with BA along with the control or without BA. Result showed that exchangeable K and P were increased by $11.4mg\;kg^{-1}$ and $163mg\;kg^{-1}$, respectively, compared to the control soil when the artificial soil was treated with BA. Microbial population and enzyme activity (Acid-phosphatase, APA) in artificial soil having BA also increased as 2 times and 10%, respectively, compared to the control soil. Comparing turfgrass growth and yield between general soil and artificial soil, about 2 times higher plant yield (fresh weight) was observed as artificial soil was applied comparing to general soil. Furthermore, nutrient concentration in turfgrass was averaged as 0.440% for $P_2O_5$, 0.456% for CaO, 1.198% for $K_2O$ and 0.188% for MgO that all values are higher than general soil (0.323% for $P_2O_5$, 0.416% for CaO, 0.610% for $K_2O$ and 0.173% for MgO). Application of BA can be useful for vegetation base material in park site.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.9
• /
• pp.4274-4282
• /
• 2011

In this study, Fenton reaction was studied for the possibility of applying as advanced treatment and its optimal condition for the removal of refractory organics from the dye wastewater. Fenton reaction was applied to remove refractory organics after the bio-treatment (secondary treatment) inside test laboratory and on-site pilot plant. Wastewater from the secondary treatment was used and its $COD_{Mn}$ was measured as 30~50mg/L. After the Fenton reaction, the optimal condition was found as pH 3~3.5, reaction time 2~2.5hr, chemical input ratio of ($FeCl_2$(33%)/$H_2O_2$(35%)) was 3 : 1. When chemical input ratio of ($FeCl_2$(33%)/$H_2O_2$(35%)) was at its optimal, amount of sludge volume ($SV_{2hr}$) was 21~28%. With pilot plant test, removal rate was heavily influenced by the hydraulic retention time(HRT), and optimum value of HRT was 2.0 hr. When pilot plant($2m^3/d$) was placed on-site and operated continuously, it showed steady and fairly good treatment of COD where COD removal rate was 60~70%, treated water showed below 20mg/L.

• The Korean Journal of Mycology
• /
• v.25 no.4 s.83
• /
• pp.369-376
• /
• 1997

These researches were carried out for improvement of medium for mycelial growth of Hericium erinaceus isolate KU-1. It grew well at pH 4 and $25^{\circ}C$. Glucose and sucrose were favorable carbon sources for mycelial growth. As nitrogen sources, ammonium acetate and arginine enhanced mycelial growth. Optimum C/N ratio was 200. Based On the results, the following recipe is suggested for synthetic medium for the mycelial growth: glucose 18.02 g, arginine 2.613 g, ammonium acetate 2.313 g, $CaCl_2\;0.33\;g$, $KH_2PO_4\;8.5\;g$, $MgSO_4{\cdot}7H_2O\;2.0\;g$, $FeSO_4{\cdot}7H_2O\;0.02\;g$, $ZnSO_4{cdot}7H_2O\;0.02\;g$, $MnSO_4{\cdot}7H_2O\;0.02\;g$, water 1 liter. This medium was superior for the mycelial growth to other conventional media such as Yeast malt extract agar (YMA), Park medium, Potato dextrose agar (PDA), Malt extract agar, Czapek-dox agar, Macaya-lizano medium and Yeast extract agar. This new synthetic medium is designated as Ko medium.