• Economic and Environmental Geology
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• v.3 no.2
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• pp.55-73
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• 1970

The district investigated covers the central and southern portions of the Uiryong Quadrangle amounting to $40km^2$ in area and is bounded approximately by geographical coordinates of $128^{\circ}$ 28' $40^{{\prime}{\prime}}{\sim}128^{\circ}$ 24' 25"E in longitude and $35^{\circ}10{\prime}{\sim}35^{\circ}14^{\prime}06^{{\prime}{\prime}}N$ in latitude. The purpose of this investigation was to provide basic information in drawing up a comprehensive development plan of the copper ore deposits known to exist in the HamanKumbuk district with special emphasis given to the ascertainment of geological and paragenetic characteristics. The area consists chiefly of shale, sandy shale and chert, all belong to Kyongsang System of Cretaceous age. Intruded into these rocks are andesite, granodiorite, basic dikes, and acidic dikes. The mineralization which took place in the area, consists of mostly fissure-filling vein deposits, numbering several tens, with varying magnitudes. The fissures and shear zones created in rocks, such as chert and granodiorite, hosted the deposition of mineralizing vapors and/or hydrothermal solutions along their openings. The strike lengths of these veins vary from 50 to 600 meters in extension and 0.1 to 3 meters in width. Although the degree of fluctuation in width is great, it averages 0.3m. The stuctural patterns, which apparently affected the deposition of veins, are fissure patterns, trend NS to $N30^{\circ}W$, and steep-pitching tension fractures as well as normal fault pattern. Ore minerals associated with vein matters are primarily chalcopyrite and small amounts of scheelite, cobaltiferous arsenopyrite, and gold and silver intimately associated with sulphide minerals. Associated with these ore mineral are pyrite, pyrrhotite, magnetite, specularite and arsenopyrite. Gangue minerals noted are quartz, calcite, chlorite, tourmaline and hornblende. In terms of the compositions of associated minerals, the vein deposits in the district could be grouped under the following four categories: 1. Pyrrhoitite, Arsenopyrite, Gold and Silver Bearing Copper Vein (Type I) 2. Calcite-Scheelite-Copper Vein (Type II) 3. Magnetite-Pyrite-Copper Vein (Type III) 4. Tourmaline Copper Vein (Type IV) Of the four types, the first and the fourth are presently yielding relatively higher grades: of copper ores and concentrates. The estimated ore reserves total some 222,000 metric tons with the following breakdown in terms of metal contents: Name of Mines Au(g/t) Ag(g/t) Cu(%) Reserves(M/T) Kunbuk 15.92 78.69 6,074 60.498 Cheil Kunbuk - - 1.040 60,847 Haman - - 2.688 101,204 222,549 As rehabilitation of old workings and/or exploration of veins at depth proceed, additional estimation of ore reserves may become apparent and necessary. With regard to the problem of beneficiation and upgrading of low-grade ores in the district, it would be advisable to make decisions on location, treating capacity and mill flowsheet after sufficient amount of exploration is completed as suggested in the report.

• Economic and Environmental Geology
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• v.48 no.3
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• pp.213-219
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• 2015

Samples from soils and crops were collected and analyzed in order to investigate the interactions of selenium among rocks, soils, and crops by hydrothermal alteration near epithermal mines in the region of Mio-san, Haenam. Soil samples included 6 samples each from mountain and farm area and compositional minerals and their contents were analyzed by water content, pH, ICP, XRD, XRF. Crop samples from onion and scallion were analyzed for chemical composition to elucidate the relationship with soils. Results from XRD analysis for soil samples showed that major compositional minerals are qualtz and feldspar, and illite, chlorite, hematite formed by hydrothermal alteration were included on a small scale. The pH ranges of soil samples from mountain and farm were measured at 4.6~4.9 and 5.2~6.7, respectively. The higher pH in farm soils may result from fertilization during agricultural activities. Results from ICP analysis showed that, compared to soil samples from mountain area with no potassium and calcium, significant amount of K and Ca were detected in soil samples from farms which is affected by fertilization. In a similar manner, potassium and calcium were absorbed and detected in crop samples at relatively high concentrations (116.89~169.79 ppm for K and 20.18~32.29 ppm for Ca). While the selenium contents in soil samples ranged from 18.35 ppb to 70.31 ppb which showed no significant difference, high concentrations of selenium were detected in onion (119.48~179.50 ppb) and scallion (146.65 ppb). These difference in enrichment for each element may result from the distinctive adsorption characteristics depending on crops.

• Tunnel and Underground Space
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• v.22 no.3
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• pp.163-172
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• 2012

As more diesel engines have been employed in underground limestone mines with large cross section, underground space environment is worsened by diesel exhausts and heat flow. This paper aims for the ultimate goal to optimize the work place environment through assuring the optimal required ventilation rate based on the analysis of the airflow, diesel exhaust gas concentrations and the effects of mechanization and deepening working face on temperature and humidity. Due to the insufficient capacity of the main exhaust fan and poor airway management, stagnant airflows were observed at various locations, while the flow direction was reversed instantly with passing diesel equipment and the flow reversal was also made by the seasonal variation of the outside surface weather. During the loading operation, CO concentration measurements were found to be frequently higher than the threshold limit of 50 ppm, and most of the $NO_2$ measurements during drilling and loading operations shows even more serious levels surpassing the permissible limit of 3 ppm. The actual ventilation quantity was considerably less than the required quantity estimated by the mine health and safety law, and this shortage problem was less serious in colder winter showing more effectiveness of the natural ventilation.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.674-683
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• 2010

The current study was performed to examine the agricultural suitability of the cultivated upland nearby abandoned mining areas in Korea using three different scientific risk assessment models of Korea, USA and UK. For this, three mining sites DM, MG and KS were selected among 687 abandoned mines through preliminary risk assessment. A wide range of parameters were obtained through analysis of both soil and crop samples from the selected areas for heavy metal concentration and questionnaires to the communities along with the selected mining sites. Heavy metal concentration in soil samples was lower than the values previously reported by the Ministry of Environment (ME, 2002). However, both As and Cd concentration in the soil samples exceeded the concern level for agricultural area of the Soil Environment Conservation Act. Judging from the contaminant criteria for the crops, only Zn level in pepper, soybean and corn from the mining area DM exceeded the criteria whereas As, Cd, $Cr^{6+}$, Cu, Hg, Ni, Pb did not exceed the criteria. It was demonstrated that there would be human health risk by Pb accumulated in crops from both mining areas MG and KS when estimated by the risk assessment models of Korea and USA. Against it, results of the risk assessment model of UK showed human health risk by Pb in the crops from all study areas.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.2
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• pp.115-126
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• 2017

There is an increasing concern over arsenic (As) contamination in rice. This study was conducted to develope a prediction model for As uptake by rice based on the physico-chemical properties of soil. Soil and brown rice samples were collected from 46 sites in paddy fields near three different areas of closed mines and industrial complexes. Total As concentration, soil pH, Al oxide, available phosphorus (avail-P), organic matter (OM) content, and clay content in the soil samples were determined. Also, 1.0 N HCl, 1.0 M $NH_4NO_3$, 0.01 M $Ca(NO_3)_2$, and Mehlich 3 extractable-As in the soils were measured as phytoavailable As concentration in soil. Total As concentration in brown rice samples was also determined. Relationships among As concentrations in brown rice, total As concentrations in soils, and selected soil properties were as follows: As concentration in brown rice was negatively correlated with soil pH value, where as it was positively correlated with Al oxide concentration, avail-P concentration, and OM content in soil. In addition, the concentration of As in brown rice was statistically correlated only with 1.0 N HCl-extractable As in soil. Also, using multiple stepwise regression analysis, a modelling equation was created to predict As concentration in brown rice as affected by selected soil properties including soil As concentration. Prediction of As uptake by rice was delineated by the model [As in brown rice = 0.352 + $0.00109^*$ HCl extractable As in soil + $0.00002^*$ Al oxide + $0.0097^*$ OM + $0.00061^*$ avail-P - $0.0332^*$ soil pH] ($R=0.714^{***}$). The concentrations of As in brown rice estimated by the modelling equation were statistically acceptable because normalized mean error (NME) and normalized root mean square error (NRMSE) values were -0.055 and 0.2229, respectively, when compared with measured As concentration in the plant.

• Journal of the Mineralogical Society of Korea
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• v.16 no.3
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• pp.265-280
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• 2003

The Mugeuk mineralized area that associated with the pull-apart type Cretaceous Eumseong basin is composed of several gold-silver vein deposits that are emplaced in late Cretaceous biotite granite. The gold-silver deposits in the area show various hydrothermal alteration zones as well as Au/Ag ratios and ore mineralogy. The Geumbong mine showing relatively high gold fineness is composed of multiple veins and show alteration pattern; vein \longrightarrow phyllic \longrightarrow subphyllic \longrightarrow propylitic \longrightarrow subpropylitic zone. In contrast, The Taegeuk mines show the low fineness values, in far southern part are characterized by increasing tendency of simple and/or stockwork veins. The deposit displays alteration pattern; vein \longrightarrow propylitic \longrightarrow subpropylitic zone. Variations of alteration zone with depth show that phyllic zone are dominant in deeper level and propylitic zone sporadically overlapped by argillic zone are dominant in shallow level. The differences of alteration pattern between the gold-silver deposits are reflect the evolution of the hydrothermal fluids; the ore-forming fluids of the Geumbong mine are at relatively high temperature and salinity and highly-evolved meteoric water, developing phyllic zone, the Taegeuk mine containing greater amounts of less-evolved meteoric waters shows relatively low temperature and salinity in ore-forming fluids, developing propylitic zone. The various physicochemical environment for gold-silver mineralization in the Mugeuk mineralized area is due to proximity from heat source area (Mugeuk mine) to marginal area (Taegeuk mine) in a geothermal field. Therefore, it is suggested that the criteria for project exploration in the area are to focus on the area proximal to heat source and phyllic zone.

• Journal of the Mineralogical Society of Korea
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• v.25 no.1
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• pp.9-21
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• 2012

Six serpentine mines are found in South Korea. We investigated occurrence, characteristics and origin of constituent minerals of Bibong serpentine mine in Chungcheongnam-do. We also analyzed the properties of serpentine minerals using XRD, XRF, SEM/EDS, FT-IR, EPMA and polarized microscope. The serpentinite of Bibong mine occurs as intruded body within the Precambrian metasedimentary rocks. Various minerals such as serpentine, forsterite, pyroxene, tremolite, magnetite, chlorite, mica, talc and dolomite are occurre. Five distinctive mineral assemblage types are observed in the serpentinite: (A) serpentine-forsterite, (B) serpentine, (C) serpentine-chlorite (vermiculite), (D) serpentine-tremolite, (E) tremolite-chlorite. Lizardite and antigorite are mainly occurred as serpentine minerals and chrysotile is partly included. From the study of mineral compositions and occurrence of serpentinite body, serpentine formed by hydrothermal alteration of ultramafic rock consisting mainly of forsterite, and altered minerals such as chlorite and tremolite subsequently formed by secondary hydrothermal alteration.

• Resources Recycling
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• v.20 no.3
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• pp.12-27
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• 2011

DOWA group has been working on metal recycling applying the smelting and refining process of KOSAKA Smelter. DOWA has developed it's metal recycling technologies through the treatment of black ore(complex sulfide ores) that contain many kinds of non-ferrous metals. In addition to these special technologies, DOWA has strengthened its hydrometallurgical process of precious metals and ability to deal with low-grade materials such as used electrical appliances or vehicles. On the other hand, JX Nippon Mining & Metals Corporation(JX-NMMC) carries out its metal recycling and industrial waste treatment businesses employing advanced separation, extraction and refining technologies developed through its extensive experience in the smelting of non-ferrous metals. JX-NMMC collects approximately 100,000t/y of copper and precious metal scraps from waste sources such as electronic parts, mobile phones, catalytic converters, print circuit boards and gold plated parts. These items are recycled through the smelting and refining operations of Saganoseki smelter and Hitachi Metal-recycling complex(HMC). In this like, metal recycling industries combined with environmental business service in Japan have been developed through excellent technologies for mineral processing and non-ferrous smelting. Also, both group, Dowa and JX-NMMC, were contributed to establish Japan's recycling-oriented society as the typical leading company of non-ferrous smelting. Now. it is an important issue to set up the collection system for e-waste.

• Resources Recycling
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• v.19 no.2
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• pp.35-44
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• 2010

As the competition of acquiring foreign resources of advanced countries and developing countries intensifies, South Korea which imports most of the mineral resources, started to re-develop domestic mines for molybdenite ore, in order to secure stable natural resources and decrease foreign currency expense. In this study, as a result of performing XRD and composite analysis on Dongwon NMC's (the sole producer of molybdenite ore in Korea) final concentrate(Mo 50.4%), Quartz, Grossular and Hedenbergite exists as impurities and size analysis showed that in relative coarse particle range of 60~140 mesh was formed with high grade over 57% Mo. Also, a test was performed to confirm the possibilities of increasing the grade and recovery of Dong won NMC's final ore. As a result, Mo 58.6% ($MoS_2$ 97.83%) was obtained with 87.47% recovery at a condition of 15 minutes grinding time, Kerosene as collector 0.1 l/ton, AF as Frother 65 7.2 l/ton, wash water of 630 ml/min and air flow rate of 1,197 ml/min.

• Economic and Environmental Geology
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• v.33 no.2
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• pp.91-100
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• 2000

It has been more than ten years since Dukun mine was abandoned. Tailings of waste deposits and slime dumps in the abandoned Dukum mine have been left to be deserted for fifty years. The results of fifty years of neglecting are nothing short of major environmental problems. Slime dumps have been exposed to air and water in the mine over ten years and then soil profile has been formed well. Soil in the upper layer (A horizon) is the light gray color due to the leaching of cations. Soil in the lower layer (A2 horizon, 0.2∼0.3m)is tinted with reddish brown and yellowish brown color due to the development of iron oxides and iron hydroxides. Soil in the lower part of B horizon of (1.0∼3.0m) with the growth of copper and zinc oxides exposes to the bluish green, light blue, and dark gray. Ranging from 3m to 8m in depth, 85 samples were taken from 22 sampling sites with 50m intervals located on the slime dump area with hand auger and trench (open cut). As tailings was distributed, heavy metal elements extracted by the process of surface water and ground water move and disperse in to the hydrosphere. Waste dumps were distributed in and around the mine and water draining from those dumps be a potential source of contamination. Soils, thus, can be dispersed into downslope and downstream through wind and water by clastic movement. These materials may be deposited in another horizon if the water is withdrawn, or if the materials are precipitated as a result of differences in pH, or other conditions in deeper horizons. These were primarily associated with acid mine drainage. The characteristics and rate of release of acid mine drainage are influenced by various chemical and biological reactions at the source of acid generations. Prolonged extration of heavy metal elements has a detrimental effect on the agricultural land and residental area. Twenty soil samples were collected from the agricultural land in the area (0∼30 cm). Seventeen samples were also taken from the sediment in the stream running alongside the dumps. The dispersion patterns of heavy metal elements are as follows: The content of As ranged 2∼6 ppm in a horizon, 20∼125 ppm in B horizon with large amount of clay mineral is concentrated and the content of Cd ranged 1∼2 ppm in A horizon, 4∼22 ppm in B horizon. Like Cd, the content of As, Cu, Zn, Pb in B horizon is higher than that in A horizon (approximately 5∼100 times). When soil formation proceeds in stages, it is necessary to investicate the B horizon with the concentration of heavy metal and preventive measures will have to established.