• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2006.04a
• /
• pp.209-212
• /
• 2006

Using sulfur sotope analysis of dissolved sulfate in surface water, we have investigated the source of sulfate in order to identify the abandoned metallic mines, which have the potential of heavy metal contamination within watershed. The range of the sulfur isotope values for dissolved sulfate in stream waters (DD-1 and 2) are similar to those of sulfides from the Dunjun mine, which suggests that oxidation of sulfides is the principal source of $SO_4^{2-}$ in these stream waters. Also, heavier sulfur isotopes in waters near Baekjun and Hamchang mines imply the possibility of contamination in waters by these metallic mines.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2003.04a
• /
• pp.389-392
• /
• 2003

Coalfields in Korea have been grouped into thirteen based on mainly geographycal and geological structure, ten out of which have been developed. To classify the phisico-chemical characteristics of mine drainage from each coalfield and, if possible, to clarify the intrinsic reasons of them. Sampling of waters from 59 mines in eight coalfields has been carried out. Higher pH of drainage water from the mines of the Cungchung coalfield belong to the Beading system, Mesozoic era than those belong to the Pyungan system, Proterozoic era is due to the low content of sulfides of neighboring strata. The drainage from coal beds overlying limestone bed mostly show high pH. Waters from the Gangrung and Samchuck coalfields coal beds are located within black shale formation which contains a lot of sulfides showed mostly very high metal and S $O_{4}$$^{2-}$ concentrations.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09b
• /
• pp.918-920
• /
• 2006

Metal sulfide powders such as MnS, $MoS_2$ and FeS are simply used to the machinery processing improvement agent and solid lubricant in powder metallurgy industrial. And then, metal sulfide powders have received relatively little attention from powder metallurgy. Recently, the portable machine is one of the important interfaces between human or human and electronic machine. With the increase of the intelligent activity, the social and industrial demands for information display device and power source are increasing. The transition metal sulfide materials (FeS, ZnS) have received considerable attention due to the large variety of its electric, optical and magnetic properties. Among the metal sulfide, $FeS_2$ is appealing superior material for applications in $Li-2^{nd}$ battery because of high capacity. ZnS is also a famous phosphor material with various luminescence properties, such as photoluminescence (PL) and electroluminescence (EL). So generally used in the fields of display, sensors and laser. Metal sulfide materials, therefore, are provided for most widely application in all industries. In recent years, material researchers have become increasingly interested in studying with synthesis of metal sulfide.

• Economic and Environmental Geology
• /
• v.29 no.4
• /
• pp.411-419
• /
• 1996

The Janggun magnetite deposits occur as the lens-shaped magnesian skarn, magnetite and base-metal sulfide orebodies developed in the Cambrian Janggun Limestone Formation. The K-Ar age of alteration sericite indicates that the mineralization took place during late Cretaceous age (107 to 70 Ma). The ore deposition is divided into two stages as a early skarn and late hydrothermal stage. Mineralogy of skara stage (107 Ma) consists of iron oxide, base-metal sulfides, Mg-Fe carbonates and some Mg- and Ca-skarn minerals, and those of the hydrothermal stage (70 Ma) is deposited base-metal sulfides, some Sb- and Sn-sulfosalts, and native bismuth. Based on mineral assemblages, chemical compositions and thermodynamic considerations, the formation temperature, $-logfs_2$, $-logfo_2$ and pH of ore fluids progressively decreased and/or increased with time from skarn stage (433 to $345^{\circ}C$, 8.8 to 9.9 atm, 29.4 to 31.6 atm, and 6.1 to 7.2) to hydrothermal stage (245 to $315^{\circ}C$, 11.2 to 12.3 atm, 33.6 to 35.4 atm, and 7.3 to 7.8). The ${\delta}^{34}S$ values of sulfides have a wide range between 3.2 to 11.6‰. The calculated ${\delta}^{34}S_{H_2S}$ values of ore fluids are relatively homo-geneous as 2.9 to 5.4‰ (skam stage) and 8.7 to 13.5‰ (hydrothermal stage), which are a deep-seated igneous source of sulfur indicates progressive increasing due to the mixing of oxidized sedimentary sulfur with increasing paragenetic time. The ${\delta}^{13}C$ values of carbonates in ores range from -4.6 to -2.5‰. Oxygen and hydrogen isotope data revealed that the ${\delta}^{38}O_{H_2O}$ and ${\delta}D$ values of ore fluids decreased gradually with time from 14.7 to 1.8‰ and -85 to -73‰ (skarn stage), and from 11.1 to -0.2‰ and -87 to -80‰ (hydrothermal stage), respectively. This indicates that magmatic water was dominant during the early skarn mineralization but was progressively replaced by meteoric water during the later hydrothermal replacement.

• Journal of Environmental Science International
• /
• v.8 no.3
• /
• pp.393-397
• /
• 1999

Among various reactions which metal sulfides can undergo in the reducing environment, the lattice exchange reaction was examined in a attempt to selectively remove heavy metal ions contained in the Fe-Coagulants acid solution. We have examined Zeta potential along with pHs to investigate surface characteristics of ${FeS}_{(s)}$. As a result of this experiment, zero point charge(ZPC) of FeS is pH 7 and zeta potential which resulted from solid solution reaction between Pb(II) and ${FeS}_{(s)}$ is similar to that of ${PbS}_{(s)}$. Solubility characteristics of ${FeS}_{(s)}$ is appeared to that dissolved Fe(II) concentration increased in less than pH 4, and also increased with increasing heavy metal concentration. Various heavy metal ions(Pb(II), Cu(II), Zn(II)) contained in Fe-coagulants acid solution were removed selectively more than ninety-five percent in the rang of pH 2.5~10 by ${FeS}_{(s)}$. From the above experiments, therefore, We could know that the products of reaction between heavy metal ions and $FeS_{(S)}$ are mental sulfide such as $PbS_{(S)}$, $CuS_{(S)}$ and $ZnS_{(S)}$.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2014.11a
• /
• pp.140-141
• /
• 2014

차세대 전극 재료의 개발은 리튬 전지, 슈퍼 축전지, 전력 공급을 포함하는 에너지 저장 매체의 연구에 중심이 되는 요소이다. 이 가운데 금속황화물은 독특하고 우수한 특성 때문에 차세대 전극 재료로서 상당히 주목을 받고 있는 재료이다. 하지만 실제 응용 측면에 있어서 충 방전 관련된 속도와 안정성의 한계가 가장 큰 장애 요소이다. 이러한 한계를 극복하고자 나노구조화에 대한 연구가 집중적으로 진행되고 있다. 본 논문에서는 금속황화물의 에너지 저장 매체로서의 연구 내용을 기술하였다.

• Economic and Environmental Geology
• /
• v.20 no.2
• /
• pp.97-106
• /
• 1987

The geology of the Bupyeong mine area is consisted of Precambrian Gyeonggi gneiss complex and Mesozoic igneous rocks; i.e., pyroclastic rocks, intrusive breccia, granite and felsic porphyries which were formed during a Jurassic to early Cretaceous resurgent caldera evolution. Granites are not observed on the surface and in the underground of the mine. Bupyeong silver deposits occur as stockworks of base metal sulfides- minor silver minerals-quartz - carbonate veinlets, hosted by pyroclastic rocks and intrusive breccia at the southwestern margin of the caldera. Silver occurs mainly as native silver, and other silver minerals, minor in quantity, are argentite, tetrahedrite-freibergite, pyrargyrite, polybasite, canfieldite and dyscrasite. The average grade of silver ore is about 180g/t Ag. Discrimination of silver ore from the country rocks depends largely on the chemical analyses of rock samples taken every two meters from tunnels, diamond-drilling cores and mining stopes, because silver minerals are hardly observed in the ore by crude eye, and silver orebodies do not properly coincide with the concentrated zone of base metal sulfides which were precipitated at the earlier stage than the stage of precipitation of native silver. General characteristics of the loci of the silver orebodies are as follows; (1) The host rocks of orebodies are pyroclastic rocks and intrusive breccia. (2) Many of the orebodies are distributed around Gyeonggi gneiss complex. Especially where the paleotopography of gneiss complex shows a gradual slope, the basal stratigraphic horizon of the pyroclastic rocks unconformably overlying the gneiss complex offered a favorable loci of high grade ore. (3) $N5^{\circ}W$ to $N15^{\circ}$ E-striking faults played an important role in the localization of the orebodies. (4) Conduits of intrusive breccia within the gneiss complex, through which the intrusive breccia intruded into the upper pyroclastic rocks, exist beneath most of the main orebodies. This suggests that the conduits of intrusive breccia served as channelways for the migration of ore fluids.

• Nuclear Engineering and Technology
• /
• v.40 no.3
• /
• pp.225-232
• /
• 2008

To understand the effect of the cyclic strain rate on the environmentally assisted cracking behaviors of SA508 Gr.1a low alloy steel in deoxygenated water at $310^{\circ}C$, the fatigue surface and a sectioned area of specimens were observed after low cycle fatigue tests. On the fatigue surface of the specimen tested at a strain rate of 0.008 %/s, unclear ductile striations and a blunt crack tip were observed. Therefore, metal dissolution could be the main cracking mechanism of the material at this strain rate. On the other hand, on the fatigue surfaces of the specimens tested at strain rates of 0.04 and 0.4 %/s, brittle cracks and flat facets, which are evidences of the hydrogen induced cracking, were observed. In addition, a tendency of linkage between the main crack and the micro-cracks was observed on the sectioned area. Therefore, at higher strain rates, the main cracking mechanism could be hydrogen induced cracking. Additionally, evidence of the dissolved MnS inclusions was observed on the fatigue surface from energy dispersive x-ray spectrometer analyses. Thus, despite the low sulfur content of the test material, the sulfides seem to contribute to environmentally assisted cracking of SA508 Gr.1a low alloy steel in deoxygenated water at $310^{\circ}C$.

• Economic and Environmental Geology
• /
• v.21 no.3
• /
• pp.269-276
• /
• 1988

Ore deposits of Dadeok mine, the largest in the Bonghwa gold mining district, are composed of numerous gold and silver-bearing quartz veins emplaced in granite batholith. Mineralization of the Pungjeong vein, one of the representative vein in the mine was investigated. K-Ar age of sericite in the vein is $84{\pm}5$ Ma. Hypogene 6pen-space filling can be devided into four paragenetic stages; (1) fine grained quartz and carbonate; (2) quartz and carbonates with base metal sulfides, electrum, native silver, argentite, polybasite, freibergite, pyrargyrite, and Cu-Ag-Fe-S minerals; (3) quartz with base metal sulfides; (4) quartz and calcite with or without pyrite. Composition of electrum ranges from 44.17 to 56.50 atomic % Ag. Meanwhile FeS content of sphalerite coexisting with elctrum in stage II range from 0.01 to 1.67 mol. %. Homogenization temperatures for quartz and sphalerite of stage II ($239^{\circ}$ to $310^{\circ}C$), quartz of stage III ($206^{\circ}$ to $255^{\circ}C$) and quartz and calcite of stage IV ($232^{\circ}$ to $253^{\circ}C$) show little time-space variation during mineralization. Salinities of the fluid inclusions range from 5.5 to 12.8wt% NaCI in stage II, 7.3 to 12.3wt% in stage III and 4.5 to 8.0wt% in stage IV. Based on the homogenization temperatures, Fe content of sphalerite and Ag content of electrum, tempera ture and sulfur fugacity for stage II are estimated to be $208^{\circ}$ to $310^{\circ}C$ and $10^{-9.2}-10^{-12.8}$ bars, respectively.

• Resources Recycling
• /
• v.10 no.1
• /
• pp.49-55
• /
• 2001

The strategy of recovering metals from scrap is in general much different from primary sources. One of the main differences between the treatment of scrap and that of primary sources lies with the fact that metals are frequently associated with other met-als to form alloys in scrap, while metals occur in primary sources as oxides or sulfides. In this paper, factors affecting the dis-solution behavior of metals from various alloy systems have been reviewed and discussed. Specific examples have been drawn from Au/Ag, Au/cu and Ag/cu systems. Results of the dissolution behavior of various metals from these alloys have been reviewed and compared to the dissolution behavior of single metal systems in various lixiviants such as acids, cyanide and ammonia. It has been observed that the presence of other metals in alloys would significantly affect the dissolution rate of the metal in question. The leaching behavior of metals from homogeneous alloys relies on the chemical interaction between atoms in the lattice of the alloys, while that from heterogeneous alloys is affected by galvanic interaction established in the solution The manner in which the dissolution of a certain metal is influenced by surrounding metals has been discussed in terms of pas-sive and noble nature of the metal in relation to the neighboring metals. The role of the standard electrochemical Potential of these metals on the selective dissolution for a given lixiviant has also been discussed.