여진우 Jin Woo Yeo , 김영규 Yeongkyoo Kim

DOI: Vol.32(No.2) 79-86, 2019

The white aluminum phases in acid mine drainage usually precipitates when mixed with stream waters with relatively high pH. The minerals in white precipitates play important roles in controlling the behavior of heavy metals by adsorbing and coprecipitation. By the phase transition of these minerals in white precipitates, dissolution and readsorption of heavy metals may occur. This study was conducted to obtain preliminary information on the phase transition of the mineral phases in white precipitates. In this study, the mineral phase changes in the white precipitates collected from the stream around Dogye Mining Site over time were investigated with different pH values and temperatures. White precipitates consist mainly of basaluminite, amorphous Al(OH)₃ and a small amount of Al₁₃-tridecamer. During aging, the incongruent dissolution of the basaluminite occurs first, increasing the content of the amorphous Al(OH)₃. After that, pseudoboehmite is finally precipitated following the precursor phase of pseudoboehmite. At 80 °C, this series of processes was clearly observed, but at relatively low temperatures, no noticeable changes were observed from the initial condition with coexisting basaluminite and amorphous Al(OH)₃. At high pH, the desorption of SO₄^2- group in basaluminite was initiated to promote phase transition to the pseudoboehmite precursor. Over time, the solution pH decreases due to the dissolution and phase transition of the minerals, and even after the precipitation of pseudoboehmite, only the particle size slightly increased but no clear cystal form was observed.

Basaluminite, pseudoboehmite, 상전이, pH, 온도, phase transition, temperature

유봉철 Bong Chul Yoo , 호르게아꼬스타 Jorge Acosta

DOI: Vol.32(No.2) 87-102, 2019

Pallancata Ag mine is located at the Ayacucho region 520 km southeast of Lima. The geology of mine area consists of mainly Cenozoic volcanic-intrusive rocks, which are composed of tuff, andesitic lava, andesitic tuff, pyroclastic flow, volcano clasts, rhyolite and quartz monzonite. This mine have about 100 quartz veins in tuff filling regional faults orienting NW, NE and EW directions. The Ag grades in quartz veins are from 40 to 1,000 g/t. Quartz veins vary from 0.1 m to 25 m in thickness and extend to about 3,000 m in strike length. Quartz veins show following textures including zonation, cavity, massive, breccia, crustiform, colloform and comb textures. Wallrock alteration features including silicification, sericitization, pyritization, chloritization and argillitization are obvious. The quartz veins contain calcite, chalcedony, adularia, fluorite, rutile, zircon, apatite, Fe oxide, REE mineral, Cr oxide, Al-Si-O mineral, pyrite, sphalerite, chalcopyrite, galena, electrum, proustite-pyrargyrite, pearceite-polybasite and acanthite. The temperature and sulfur fugacity (f_s2) of the Ag mineralization estimated from the mineral assemblages and mineral compositions are ranging from 118 to 222 °C and from 10^-20.8 to 10^-13.2 atm, respectively. The relatively low temperature and sulfur-oxygen fugacities in the hydrothermal fluids during the Ag mineralization in Pallancata might be due to cooling and/or boiling of Ag-bearing fluids by mixing of meteoric water in the relatively shallow hydrothermal environment. The hydrothermal condition may be corresponding to an intermediate sulfidation epithermal mineralization.

Pallancata 은 광산, 석영맥, 모암변질, 산출광물, 화학조성, Pallancata Ag mine, quartz vein, wall-rock alteration, mineralogy, geochemistry

서정민 Jeong Min Seo , 김영훈 Young Hun Kim , 권혁진 Hyuk Jin Kwon , 김정진 Jeong Jin Kim

DOI: Vol.32(No.2) 103-111, 2019

In this study, characteristics of sediments and suspended solids flowing into Andong and Imha Dam was analyzed by color, X-ray diffraction and ICP/MS analysis. The minerals of sediments and suspended solid consist mainly of quartz, albite, chlorite, illite and small amounts of montmorillonite and kaolinite. Unlike the Andong Dam, the Imha Dam sediments contain large amounts of calcite. Color of sediments and suspended solids varies from grayish brown to dark orange. The concentrations of major heavy metals of sediments and suspended solids in the Andong and the Imha Dam are higher than the US National Oceanic and Atmospheric Administration standard values. The concentration of heavy metals in sediments of Andong is higher than that of Imha Dam because concentration of heavy metals in the suspended solid flowing into Andong is higher than that of Imha Dam.

안동댐, 임하댐, 퇴적물, 부유물질, 중금속, Andong Dam, Imha Dam, sediments, suspended solid, heavy metal

이종주 Jong-ju Lee , 온현성 Hyun-sung On , 박천영 Cheon-young Park

DOI: Vol.32(No.2) 113-126, 2019

This study aimed to effectively dissolve sulfide minerals through microwave-nitric acid leaching of invisible gold concentrate and then recover gold from the solid-residue with fire assay. For the purposes, this study conducted microwave-nitric acid leaching experiments to examine nitric acid concentration, time of microwave leaching, and sample addition effect. As results of the experiments, this study discovered that the weight loss rate of solid-residue increased as nitric acid concentration and microwave leaching time increased while weight loss rate decreased as sample addition increased. In an XRD analysis with solid-residue, it was discovered that pyrite completely disappeared when the nitric acid concentrate was 6 M and the microwave leaching time was 18 minutes. When a fire assay was carried out with solid-residue, gold particles with more content were recovered as nitric acid concentration and microwave leaching time increased whereas gold particles with more gold content were recovered as the sample addition decreased.

비-가시성 금 정광, 마이크로웨이브-질산용출, 납-시금법, 금 입자, invisible gold concentrate, microwave-nitric acid leaching, lead-fire assay, gold particle

유봉철 Bong Chul Yoo

DOI: Vol.32(No.2) 127-143, 2019

The geology of the Chulmasan area consists of Precambrain Sogeunri formation, granitic gneiss, foliated biotite granite, foliated mica granite, basic dyke and acidic dyke. REE mineralization in the area occurs at granitic gneiss and foliated mica granite. Minerals with minor amounts of REE and Th from granitic gneiss and foliated mica granite are zircon (Y₂O₃ 0.00~1.18 wt.%, Gd₂O₃ 0.00~0.59 wt.%, Er₂O₃ 0.00~0.22 wt.%, Yb₂O₃ 0.00~0.34 wt.%, Lu₂O₃ 0.00~0.48 wt.%, ThO₂ 0.00~0.33 wt.%), thorianite (Nd₂O₃ 0.00~0.24 wt.%, Lu₂O₃ 0.00~0.26 wt.%), berthierine (La₂O₃ 0.04~0.26 wt.%, Nd₂O₃ 0.00~0.20 wt.%, Tb₂O₃ 0.04~0.12 wt.%, Dy₂O₃ 0.17~0.26 wt.%, Er₂O₃ 0.33~0.44 wt.%, Lu₂O₃ 0.00~0.19 wt.%, ThO₂ 0.61~0.93 wt.%), chlorite (La₂O₃ 0.44~0.68 wt.%, Ce₂O₃ 0.12~0.13 wt.%, Nd₂O₃ 0.31~0.44 wt.%, Eu₂O₃ 0.03~0.08 wt.%, Dy₂O₃ 0.09~0.21 wt.%, Ho₂O₃ 0.04~0.14 wt.%, Er₂O₃ 0.18~0.32 wt.%, Lu₂O₃ 0.07~0.21 wt.%, ThO₂ 0.00~0.97 wt.%), biotite (Nd₂O₃ 0.02~0.08 wt.%, Gd₂O₃ 0.07~0.08 wt.%, Tb₂O₃ 0.02~0.07 wt.%, Dy₂O₃ 0.35~0.43 wt.%, Ho₂O₃ 0.15~0.26 wt.%, Er₂O₃ 0.24~0.28 wt.%, Yb₂O₃ 0.06~0.18 wt.%, ThO₂ 0.00~0.12 wt.%), orthoclase (Dy₂O₃ 0.05~0.12 wt.%, Ho₂O₃ 0.05~0.06 wt.%, Er₂O₃ 0.28 wt.%, Yb₂O₃ 0.06~0.12 wt.%) and plagioclase (Ho₂O₃ 0.01~0.03 wt.%, Er₂O₃ 0.10~0.27 wt.%, ThO₂ 0.11~0.13 wt.%). REE minerals (bastnaesite and fergusonite) were sealed fractures in mainly fledspar, mica, zircon, apatite and ilmenite. Therefore, bastnaesite and fergusonite from the Chulmasan area were formed from redissolution/reconcentration of REE-and Th-bearing minerals from granitic gneiss and foliated mica granite at late stage by several igneous activies and metamorphism.

철마산, 지질, 희토류 광화작용, 희토류 광물, 농집, Chulmasan, geology, REE mineralization, REE mineralogy, concentration

조현구 Hyen Goo Cho , 구효진 Hyo Jin Koo

DOI: Vol.32(No.2) 145-150, 2019

As the spirit of reconciliation between the two Koreas ripens, the integration of mineral names is required in preparing the reunification between the South and North Koreas. Currently, mineral names in Korean do not adopt the guideline for romanization of Korean that was proposed by the National Institute of the Korean Language (NIKL), and different names are often used for an identical mineral species. Here, for mineral names in Korean, we suggest using (1) the suffix, “sok”, both for metallic and non-metallic minerals, (2) names in the NIKL example-list if available, (3) the suffix “sok” for minerals whose names are based on the names of persons or localities.

광물명, 외래어 표기법, 금속광물, 인명, 지명, mineral names, romanization of Korean, metallic minerals, person names, locality names