• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.493-500
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• 2003

The effect of reductive treatment with elemental iron on the extent of mineralization by Fenton oxidation was studied for the explosive 2,4,6-trinitrotoluene (TNT) and hexahydro-l,3,5-trinitro-l,3,5-triazine (RDX) using a completely-stirred tank reactor (CSTR). The results support the hypothesis that TNT and RDX are reduced with elemental iron to products that are oxidized more rapidly and completely by Fenton's reagent. Iron pretreatment enhanced the extent of TOC removal by approximately $20\%\;and\;60\%$ for TNT and RDX, respectively. Complete TOC removal was achieved for TNT and RDX solutions with iron pretreatment under optimal conditions. On the other hand, without iron pretreatment, complete mineralization of TNT and RDX solutions were not achieved even with much higher $H_2O_2$ and $Fe^{2+}$ concentrations. The bench-scale iron treatment-Fenton oxidation integrated system showed more than $95\%$ TOC removal for TNT and RDX solutions under optimal conditions. The proposed zero-valent iron-Fenton process was evaluated with pink water from the Iowa Army ammunition plant. Results from batch and column experiments show that TNT, RDX, and octahydro-l,3,5,7-tetranitro-l,3,5,7-tetrazocine (HMX) were completely removed from the pink water and that triaminotoluene (TAT) and ${NH_4}^+$ were recovered as products in reduction with zero-valent iron. By using an integrated system, $83.3\pm4.2\%$ of TOC was removed in a CSTR with 10 mM of $Fe^{2+}$ and 50 mM of $H_2O_2$. These results suggest that the reduction products of TNT and RDX are more rapidly and completely mineralized by Fenton oxidation and that a sequential iron treatment-Fenton oxidation process may be a viable technology for pink water treatment.

• 자원환경지질
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• 제26권3호
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• pp.311-325
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• 1993

The Ohto and Tohyun copper mine which are located 4 km southeast of Euiseong, Gyeongsangbukdo, Republic of Korea show various common geologic and mineralogic features. Both copper deposits are of hydrothermal-vein types, and associated with fracture system developed during formation of the Geumseong-san caldera in late Cretaceous age. According to structures and mineral assemblages, the mineralization processes have progressed in four stages: three hypogene mineralization stages and one supergene stage. Three hypogene stages are 1) stage I forming $N5{\sim}20^{\circ}E$ veins in the Ohto mine, 2) stage II building $N5^{\circ}W{\sim}N5^{\circ}E$ veins in the Tohyun mine, and 3) stage ill bringing $N80^{\circ}E$ veins which crosscut veins of the stage II. The vein ores consist mainly of pyrite, arsenopyrite, galena and chalcopyrite, minor or trace amounts of magnetite, hematite, pyrrhotite, stannite, bournonite, boulangerite, stibnite, galenobismutite, native bismuth, marcasite, geothite and malachite. The main gangue minerals are quartz and calcite. Wallrock is altered by sericitization, chloritization, pyritization, carbonitization and argillization. Arsenic and copper contents in arsenopyrite increase from stage I to stage III (from 31.28 to 33043 atom.% As) and (from 0.04 to 0040 atom.% Co). Going from stage I to stage III Fe and Mn contents in sphalerite decreases from 12.56 to 0.44 wt.% and from 0.24 to 0.01 wt.%, respectively. The compositional data of arsenopyrite in the early stage I indicate a temperature of $420{\sim}365^{\circ}C$ and sulfur fugacity of $10^{-6.5}{\sim}10^{-8.3}$ atm. Chalcopyrite and pyrrhotite assemblage suggest that Middle stage I was deposited at below $334^{\circ}C$. The compositional data of arsenopyrite in early stage II suggest a temperature range of $425{\sim}390^{\circ}C$ and sulfur fugacity codition of $10^{-6.4}{\sim}10^{-7.3}$ atm. Based on fluid inclusion the Middle stage II was regarded as to be deposited at $420{\sim}337^{\circ}C$ (Chi et al., 1989). Referring composition of sphalerite and stannite middle-late stage II seem to be deposited around $246^{\circ}C$ and $10^{-16.5}$ atm. sulfur fugacity. The ${\delta}^{34}S$ values of sulfide minerals in the Stage I, II, III range from 4.9 to 7.6%0 and indicate igneous ore fluid origin. Based on differences in mineral assemblages, chemical composition and chemical environments of Ohto and Tohyun mine its mineralization are considered to be formed at diffent mineralization ages and by different ore fluids.

• 자원환경지질
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• 제22권2호
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• pp.151-166
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• 1989

A study of rare-earth mineralization in Kyemyungsan metasedimentary formation of Precambrian Ogcheon Group was carried out in the Mt. Eore Area near Choongju City based on the thorium (Th) and uranium (U) count data of geophysical airborne survey. This rare-earth mineralization was found in the magnetite-bearing banded quartizite which contains diagnostically some amounts of the metamict allanite. The brown colored allanites are distributed as aggregates of fine grains and sometimes banded structures with magnetite (inter growth) along the banding. The ore bed is displaced by the small faults and granite intrusions, and separated 5 ore blocks. The dimensions of the outcrop are 50-80 m in width, 1,500 m in length with the strike of $N70-80^{\circ}E$ and dip of $50-80^{\circ}NW$. In the field, the values of total gamma ray count of GR-101A scintillometer were able to measure more than 400 cps and maximum 1,500 cps, which data are coincided with the values of GR-310 gamma ray spectrometer and the gamma ray count of well logging data. The chemical compositions of the allanites from EPMA data are ranged from$\sum^{TR_2O_3}$ 18.57% to 26.00%, and the cerium oxides ($Ce_2O_3$) of allanite are positive relation with $La_2O_3$, MgO, FeO, MnO and negative relation with $SiO_2$, $Al_2O_3$, $Nd_2O_3$. The result of Neutron Activation Analysis (N.A.A.), Multi-Channel Analysis (M.C.A.) and wet chemistry of 25 outcrop samples for the elements of REE, Zr, U, Th shows strong anomalies. The good correlation elements with the thorium (Th) are the elements of La, Ce, LREE, $TR_2O_3$, Pr, Sm, Yb, Lu by the increasing order.

• 자원환경지질
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• 제28권3호
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• pp.287-303
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• 1995

Tungsten ore deposits in China show clearly their relationship between granitoids and orebodies. All kinds of different tungsten ore deposits, having the largest ore reserves in the world, occur in China. Major tungsten deposits in 1950'years were locally confined in three provinces such as Jiangxi, Hunan and Guangdong. However, the major tungsten ore deposits are replaced by new tungsten deposits such as Sandahozhuang, Xingluokeng, Shizhuan and Daminghsan deposit which may be larger than the previous major deposits. Tungsten ore deposits of China exhibit obviously the granitoid was the ore-bringer to form tungsten ore deposits. The wolframite-bearing quarz veins in China indicate that tungsten mineralization took place by crystallization of wolframite preferentially unless $Ca^{{+}{+}}$ was introduced from outside into the magma-origin-fluid, since it is understood that the scheelite in the Sangdong ore deposit was preferentially precipitated, because of chemical affinity, from the tungsten fluid in which Fe and Ca ions were as sufficient as to form magnetite, wolframite and scheelite. Tungsten deposits in the world are divided into two systems; W-Mo-Sn system and W-Mo system. Most of tungsten deposits in China dated to about 196-116 Ma belong to the W-Mo-Sn system, while late Cretaceous tungsten deposits such as the Sangdong deposit in Korea belongs to the W-Mo system. The genetic order of tin-tungsten-molybdenum mineralization observed in the Moping tungsten mine in China and the Sangdong in Korea may be attributed to volatile pressures in the same magma chamber. It is assumed from ages of tungsten mineralizations that ore elements such as tin, tungsten and molybdenum might be generated periodically by nuclear fission and fusion in a part of the mantle and the element generated was introduced into the magma chamber. The periodical generation of elements had determined association, depletion and enrichment of tin and molybdenum in tungsten mineralization and it results in little association of cassiterite in tungsten deposit of late Cretaceous ages. Different mechanism of emplacement of the ore-bearing magma has brought various genetic types of tungsten deposits as shown in China and the world.

• 자원환경지질
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• 제54권2호
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• pp.213-232
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• 2021

Ore criteria at the Sheba Deposit indicate orogenic mineralization type. Rocks and mineral assemblages suggest low formation-temperature of green-schist facies. Pyrite found in two generations; Type1 is irregular grains, contains higher arsenic and gold contents, compared to the relatively younger phase Type2 pyrite, which is composed of euhedral grains, found adjacent to late quartz-carbonate veins or at rims of type1 pyrite. Two gold generations were identified; type1 found included in sulphides (mainly pyrite). The second gold type was remobilized (secondary) into free-lodes within silicates (mainly quartz). Gold fineness is high, as gold contains up to 95 wt. % Au, Ag up to 3.5 wt. %, and traces of Cu, Ni, and Fe. Pyrite type2 contains tiny mineral domains (rich in Al, Mn, Hg, Se, Ti, V, and Cr). Zoning, and replacement textures are common, suggesting multiple mineralization stages. The distribution and relationships of trace elements in pyrite type2 indicate three formation patterns: (1) Al, Mn, Hg, Se, Ti, V, Cr, and Sn are homogeneously distributed in pyrite, reflecting a synchronous formation. (2) As, Ni, Co, Zn, and Sb display heterogeneous distribution pattern in pyrite, which may indicate post-formation existence due to other activities. (3) Au and Ag show both distribution patterns within pyrite, suggesting that gold is found both in microscopic phases and as chemically bounded phase.

• 농업과학연구
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• 제49권3호
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• pp.463-481
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• 2022

Phosphorous (P) is considered to be one of the key essential elements demanded by crop plants. Approximately 70 - 90% of phosphatic fertilizers applied to crops are fixed in soil as Ca, Fe, and Al metal cations, which are insoluble and thus not readily available for plant uptake. Therefore, most soils are deficient in plant available P. This is usually rectified by applying phosphate fertilizers continuously, although this is not economically viable or environmentally acceptable. The present paper reviews the mechanisms involved with phosphate solubilization and mineralization by phosphate solubilizing microorganisms (PSMs) with the associated factors that determine the success. PSMs are effectively involved in mediating the bioavailability of soil P. Their contribution includes mineralization of organic P solubilization of inorganic P minerals, and storing sizable amounts of P in biomass through different mechanisms such as the production of organic and inorganic acids, H₂S, siderophores, exopolysaccharides, and production of enzymes such as phosphatases, phytase, and phosphonatases/C-P lyases, which are capable of chelating the metal ions, forming complexes, and making plant available P. PSMs manifest a wide range of metabolic functions in different environments, resulting in significantly higher plant growth, enhanced soil properties, and increased biological activities. Therefore, development of bio-inoculants with efficient novel PSM strains and further investigations on exploring such strains from diverse ecological niches with multifunctional plant-growth-promoting traits are needed.

• 자원환경지질
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• 제35권3호
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• pp.203-210
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• 2002

해저 열수 광화작용을 대효할 수 있는 황화물 침니(sulfide chimney)의 성장 메카니즘을 고찰하기 위하여 Juan de Fuca 혜령의 최남단에 위치하는 Cleft segment의 열수장(hydrothermal field)에서 회수한 비활동성이고 황화물과 실리카가 풍부한 침니를 대상으로 광물 및 유체포유물 연구를 수행하였다. 기존 연구에 의하면, Cleft sogment에는 많은 활동성 및 비활동성의 열수 분출구가 존재하는 것으로 보고되어 있다. 연구 대상 침니는 주로 비정질 실리카, 황칠석, 섬아연석 및 섬유아연석(wurtzite)으로 구성되어 있고,소량의 황동석 및 백칠석을 함유하고 있다. 유체통로로 추정되는 침니의 내부는 다공질이며, 비정질의 교질성(colloidal) 실리카로 피복되어 있다. 섬아연석과 섬유아연석으로 구성되어 있는 아연이 풍부한 황화물의 FeS 함량은 13.9~34.3 mole%의 범위를 보이며, 철이 풍부한 중심부와 철이 부족한 연변부를 지닌다. 이는 광화유체의 화학적.물리석 특성들의 변화로부터 기인되었으리라 사료된다. 침니 내부성장대별 화학조성은 열적구배 및 구성광물의 차이로 인해 다른 특징들을 보여주고 있다. 광화후기에 침전된 비정질 실리카중의 액상이 풍부한 유체포유물을 대상으로 가열 및 냉각 실험을 수행한 결과, 열수유체의 최소 포획 온도는 약 114$^{\circ}$~145$^{\circ}C$이며, 해당 염농도는 3.2~4.8 wt.% NaCl equip, 이다. 실제 열구에서 배출되는 유체 온도 자료를 입수하지는 못했지만, 본 연구를 통해서 광물의 침전작용 동안 상대적으로 저온의 침전조건이 매우 지배적이었음을 알수 있다. Juan de Fuca 해령내 Cleft seamen에서 회수된 황화물 침니는 산출형태, 교질성 조직, 전(bulk) 화학조성, 광물조합(황철석+백철석+섬유아연석+비정질 실리카) 등으로 볼 때, 기존 보고된 침니 유형보다는 상당히 낮은 온도에서 느린 유체 유동과 전도성 냉각(<25$0^{\circ}C$)에 의해 생성되었으리라 사료된다.

• 상하수도학회지
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• 제23권5호
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• pp.669-678
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• 2009

The reduction of excess activated sludge from petrochemical plant was investigated by the electro fenton (E-Fenton) process using electrogenerated hydroxyl radicals which lead to mineralization of activated sludge to $CO_2$, water and inorganic ions. Factors affecting the disintegration efficiency of excess activated sludge in E-Fenton process were examined in terms of five criteria: pH, $H_2O_2/Fe^{2+}$ molar ratio, current density, initial MLSS (mixed liquid suspended solids) concentration, $H_2O_2$ feeding mode. TSS total suspended solid and $TCOD_{cr}$ reduction rate increased with the increasing $H_2O_2/Fe^{2+}$ molar ratio and current density until 42 and $6.7 mA/cm^2$, respectively but further increase of $H_2O_2/Fe^{2+}$ molar ratio and current density would reduce the reduction rate. On the other hand, as expected, increasing pH and initial MLSS concentration of activated sludge decreas TSS and $TCOD_{cr}$ reduction rate. The E-Fenton process was gradually increased during first 30 minutes and then linearly proceed till 120 minutes. The optimal E-Fenton condition showed TSS reduction rate of 62~63% and $TCOD_{cr}$ (total chemical oxygen demand) reduction rate of 55~56%. Molar ratio $H_2O_2/Fe^{2+} = 42$ was determined as optimal E-Fenton condition with initial $Fe^{2+}$ dose of 5.4 mM and current density of $6.7{\sim}13.3 mA/cm^2$, initial MLSS of 7,600 mg/L and pH 2 were chosen as the most efficient E-Fenton condition.

• 자원환경지질
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• 제46권2호
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• pp.123-140
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• 2013

당두 연-아연 광상 주변의 지질은 선캠브리아 기반암류인 변성암류와 그 상부를 피복하는 오르도비스기의 돌로마이트, 석회암, 석회규산염암, 혼펠스, 그리고 이를 관입한 중생대와 백악기의 화강암류 및 암맥들로 구성되어있다. 광상은 오르도비스기의 석회암층 내 열극을 따라 $N20{\sim}40^{\circ}W$방향으로 교대한 연-아연 스카른광상이다. 당두광상에서 주로 개발된 광체는 -30 m level의 연장 10 m, 폭 3 m규모의 $N20^{\circ}E$, $50^{\circ}NW$방향으로 발달한 광체와 연장 15 m, 폭 3 m 규모의 $N30^{\circ}E$, $50^{\circ}NW$방향으로 발달한 광체, 포켓상 광체가 있으며, -63 m level의 폭 2 m, 연장 20 m규모의 $N20^{\circ}E$, $45^{\circ}NW$방향으로 발달한 광체가 있다. 주요 광석광물로는 섬아연석, 황동석, 자류철석, 방연석, 자철석, 황철석이 있으며, 자연창연, 휘창연석, 헤사이트, 코살라이트, 백철석이 소량 수반된다. 섬아연석의 정량분석 결과 평균 FeS 14.14~18.08 mole%, CdS 0.44~0.70 mole%, MnS 0.52~1.13, 1.53~2.09 mole%의 범위를 갖는다. 방연석은 평균 0.54 wt.%의 소량의 은을 함유하며, 일부 시료에서는 1.47 wt.%에 이르는 은을 함유하기도 한다. 코살라이트는 평균 Ag 2.43 wt.%, Bi 44.36 wt.%, Pb 35.05 wt.%의 조성을 보이며, 평균 화학식 $Pb_{1.7}Bi_{2.1}Ag_{0.2}S_5$ 로 Bi가 소량 부화되었으며, Ag를 소량 포함하는 것이 특징이다. 스카른광물로는 녹렴석, 녹니석, 석류석, 단사휘석, 투각섬석, 석영, 방해석이 있다. 광체는 중심부로부터 외곽부로 대칭적인 분포를 보이며, 중심부로부터 녹렴석-단사휘석대, 녹렴석-단사휘석-녹니석대, 녹렴석-석류석-단사휘석대 순으로 분포한다. 석류석의 화학조성은 광체 중심부에 해당하는 녹렴석-단사휘석대에서 외곽부인 녹렴석-단사휘석-녹니석대 및 녹렴석-석류석-단사휘석대로 감에 따라 그로술라의 비율이 높아지는 경향을 보인다. 단사휘석은 투휘석-헤덴버자이트 고용체로 산출되며, 녹렴석-단사휘석대에서 녹렴석-단사휘석-녹니석대, 녹렴석-석류석-단사휘석대로 감에 따라 요한세나이트의 비율이 높아지는 경향을 보인다. 광화작용은 단일광화작용에 의해 이루어졌으며, 조기는 스카른광물 정출기, 중기는 광석광물 정출기, 말기는 저온성 광석광물의 정출기이다. 주요 광석광물은 중기~말기에 걸쳐 형성되었다. 자류철석의 변질산물인 백철석-황철석의 공존 온도와 코살라이트의 형성온도로 미루어보아 저온성 광물 정출기의 온도는 $125{\sim}300^{\circ}C$로 생각된다. 광화작용에 따른 광석광물의 형성 온도에 의하면 조기에서 말기로 감에 따라 $600^{\circ}C$에서 $300^{\circ}C$ 이하의 환경까지 온도가 낮아졌을 것으로 추정된다.

• 공업화학
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• 제33권3호
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• pp.258-271
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• 2022

Ferrate (VI) [Fe(VI)] has multi-functional features, which include potential oxidant, coagulant, and disinfectant. Because of these distinctive properties, numerous studies on the synthesis of ferrate (VI) and its possible applications in a wide research areas have been investigated. This review highlights the recent development made on different synthesis methods for ferrate including wet chemical, electrochemical, and thermal methods. The recent advancements achieved in ferrate (VI) oxidation and the synergistic effect of the oxidative properties of ferrate (VI) in the presence of various compounds or materials are also included. Moreover, this review discusses the applications of ferrate (VI) for degrading various types of water pollutants and its reaction mechanism. The optimized experimental conditions and interaction mechanisms of ferrate (VI) with micro-pollutants, dyes, and other organic compounds are also elaborated upon to provide greater insight for future studies. Lastly, the limitations and prospects of the ferrate use in the treatment of polluted water are described.