• Journal of the Mineralogical Society of Korea
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• v.27 no.4
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• pp.235-242
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• 2014

Uranium can be released into the water environment from natural sources and human activities. The natural source of uranium is dominant in the Korean soil and groundwater environments. Uranium has both of radioactive and chemical toxic properties. Therefore, a drinking water contaminated with uranium has a high health risk. This study was conducted to determine the uranium concentration of water systems including small village drinking water system, groundwater for drinking water purpose, spring water, groundwater monitoring well, and emergency water suppling system. The uranium concentration was compared with domestic and other countries' standard. The contamination level was also evaluated on the basis of geological characteristics of the area. Among total 803 samples, 6 exceeded the Korean standard, $30{\mu}g/{\ell}$ and this was about 0.7% of the total sample. On the basis of geology, uranium concentration appeared to be increased in order of biotite granodiorite > biotite granite > gneissoid granite. The highest level of uranium was 12.4 in average.

• Journal of the Mineralogical Society of Korea
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• v.32 no.4
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• pp.313-321
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• 2019

Diatomite is a silicic porous sedimentary rock composed of diatom frustules, used for filtration aid, filler, absorbent, abrasive, carrier, insulator, and fertilizer. During the calcination of diatomite to improve physical properties for filtration-aid application, amorphous silica is transformed to cristobalite. X-ray diffraction and scanning electron microscopy studies were carried out for 17 diatomite samples, showing that 16 diatomite samples contain cristobalite in the range of 6~100 %. Concentration of respirable cristobalite in air is regulated as harmful substances, but the residual cristobalite in food is treated as generally safe substance. The determination procedure of cristobalite content in food was established for managing food safety. Calibration curve of cristobalite filtered on silver membrane were obtained by X-ray diffraction. The lower limit of quantification was evaluated as 2.7 mg. The cristobalite was not detected in the analyses of selected food samples using the established procedure.

• Journal of the Mineralogical Society of Korea
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• v.17 no.2
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• pp.123-133
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• 2004

Carbonate minerals are examined by cathodoluminescence microscopy and chemical analysis to characterize the carbonate materials occurring in the Tertiary marine basin. The microscopic technique with cathodoluminescence gives new informations that are not obtainable by conventional microscopic techniques. The carbonate cements in sandstones appear to be uniform with transmitted light or with crossed prisms. but the inspection with cathololuminescence reveals foraminiferal tests and rhomb crystals in the carbonate cements. The chemical analysis indicates that the intense luminescence depends mainly on the presence of$ Mn^{ 2+}$ and $Fe^{2+}$ as activator ions, but the $Fe^{2+}$ also acts as an important quencher ion when Fe concentration in dolomite is over 10,000 ppm. The dolomites, which are rich in calcium, are formed at the early stage of diagenesis at a temperature of about 60 ～ $70^{\circ}C$.

• Journal of the Mineralogical Society of Korea
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• v.9 no.2
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• pp.102-112
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• 1996

The precious serpentine, referring to a rare and highly valuable gem variety of serpentine group minerals, is found to occur in serpentinite from Booyo Gren Jade Mine which is located in Oesan-myun, Booyo-gun of Chungchungnam-do. Geommological properties of the precious serpentine have been investigated by use of polarizing microscope, specific gravity balance, refractometer, hardness pencils, X-ray diffractometer, XRF, ICP-MS analyser, and infrared absorption spectroscope.The precious serpentine from Booyo is colored deep green with oily luster and semi-transparent. It is highly tough and Mohs's scale of hardness is measured to be 5-6. Specific gravity is determined to be 2.67, and a single refractive index ND=1.56 is observed by a spot method, using sodium light source. X-ray powder diffraction data is represented by the reflection lines at 7.40(100), 4.64(25), 3.68(68), 2.757(69), 2.530(49), 2.549(32), and 1.710(21${\AA}$), which compares very well with that of antigorite of serpentine group minerals. The major chemical compositions of the precious serpentine group minerals. The major chemical compositions of the precious serpentine are SiO2 42.49%, MgO 39.08%, Fe2O3 3.85%, and H2O 11.87%. Besides, trace elements such as Cr(2188), Ni(1110ppm), Co(58ppm), and Ta (108ppm) are relatively spectrum shows peaks at 3670, 1190, 1070, 980 and 610cm-1. Strong absorption at 3670cm-1 is due to OH stretching, and 1190, 1070 and 980cm-1 due to SiO stretching. The absorption 610cm-1 is formed by alteration of pre-existing ultramafic rock, namely peridotite, with an introduction of fluid with very little content of CO2, under 400$^{\circ}C$ environment. Magnetite inclusions, finely disseminated in the precious serpentine, may be a result of Fe precipitation, during serpentinization of olivine-bearing country rock.

• Journal of the Mineralogical Society of Korea
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• v.14 no.1
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• pp.12-20
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• 2001

충북 영동군 동창광산에서 산출되는 일라이트(illite)광선의 표면화학특성을 전위차 적정 실험과 FITEQL3.2 프로그램을 이용하여 연구하였다. 정량 Xtjs 회절 분석에 의한 일라이트 광석의 광물조석은 석영 46.6% 일라이트 41.6% 카올리나이트(kaolinite) 11.8%이며 $N_2$BET 방법에 의하여 구한 비표면적은 $6.52 m^2$g이다. 전위차 적정 실험결과를 그란(Gran)법을 적용하여 구한 일라이트광석의 영전하점($pH_{pznpc}$ )은 pH 3.9 총표면 자리 밀도는 21.24 sites/$nm^2$이다. 표면 복합체 모델중 일정 용량 모델을 적용해 일라이트 광석의 표변 특성에 알맞는 모델을 찾아보았다. 일라이트 광석의 표면을 사면체 자리와 팔면체 자리로 나누어 설정한 2sites$-3pK_{ a}$s 모델은 변수값이 수렴되지않았으므로 부적절하다고 판단된다. 일라이트 광석의 표면을 하나의 균질한 흡착표면으로 가정해서 설정한 1 site -1 $K_{a}$ 와 1 site -2 $pK_{a}$ s 모델 사이에는 뚜렷한 차이는 없지만, 1 site -1 $pK_{a}$ 모델의 WSOS/DF 값이 17, 1 site - 2 $pK_a{s}$ 모델은 26으로서 앞 모델이 보다 적절하다. 이 결과는 일라이트 광석 표면에서 수소의 해리와 첨가 반응 중 첨가 반응을 무시하여도 표면반응을 설명하는 데 큰 무리가 없음을 시사한다. 가장 적절하다고 판단되는 1 site -1 $pK_{a}$ 모델의 $pK_{a}$ 값은 4.17, specific capacitance는 $6F/m^2$ 표면 자리 농도는 $1.15\Times10^{-3}$ mol/L 이다.

• Journal of the Mineralogical Society of Korea
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• v.23 no.3
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• pp.227-234
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• 2010

We investigated the effect of dry grinding of laterite on the extraction of nickel and cobalt. The major chemical compositions of the sample for this work were $SiO_2$, $Fe_2O_3$ and MgO. The sample contained 0.81% Ni and 0.02% Co. The major minerals of the sample were lizardite and quartz with minor amounts of forsterite and enstatite. The mean particle size, specific surface area and density of the ground sample decreased with increasing grinding time, while the amorphization of lizardite increased as identified by XRD analysis. The grinding enabled the extraction ratio of Ni and Co to increase by the breakdown of Mg-OH bonding in the lizardite structure. However, physical properties of quartz were not changed by grinding. The extraction ratio of Ni and Co increased with increasing grinding time. Approximately 80% of Ni and Co were extracted regardless of the kind of acid solutions when the sample was ground for 60 minutes.

• Journal of the Korean Geosynthetics Society
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• v.13 no.4
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• pp.57-68
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• 2014

This study categorizes the distributed sand around coastal area of Jeju volcanic Island into three groups according to their components, and arranges their characteristics. In the case of basic physical properties, the silicate sand has slightly greater specific gravity than general sand, and the carbonate sand with widespread distribution has a lower specific gravity. In the gross, the carbonate sand has poor particle classifying and low uniformity coefficient because carbonate minerals of relatively large grain size are mixed. The relation between compressive strength and components shows conflicting tendency that silicate and carbonate components have positive correlation and negative correlation with compressive strength, respectively. Based on the components ratio of one to one, the sand having low carbonate component ratio is expected to be able to utilize in construction fine aggregate. To compare between square root (ACI 308) and cube root (KCI 2012) of compressive strength at computation of elastic modulus, it is considered to non-dimensional elastic modulus.

• Journal of the Mineralogical Society of Korea
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• v.20 no.4
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• pp.289-302
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• 2007

Separation process of heavy minerals was performed with sand from Dunjang beach of Jaeundo, Shinangun, Chonnam, and the feasibility study separating heavy minerals was carried out, and their properties were studied. Samples were selected in three parts, which were upper part, middle part and lower part, with depth. Samples of heavy mineral groups separated with the spiral separator were chosen as starting materials, and they were separated with 3 times of table separation. Heavy minerals presenting in this area were ilmenite, zircon, rutile, anatase, monazite, and xenotime. In the results of 3 times of table separation, minor content of quartz, orthoclase, albite and muscovite were existed as gangue minerals. Accordingly, we concluded that additional specific gravity separation was needed. In the results of separation of heavy minerals by hand picking, it was confirmed that heavy minerals had various genesis because of their various roundness and color.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.387-396
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• 2022

In this study, the removal efficiencies of heavy metals were evaluated using cockle, abalone, and scallop shells. Cockle, abalone, and scallop are composed mainly of aragonite, aragonite, and calcite, and calcite, respectively. The specific surface area of each shell varies from 2.7241 m²/g to 4.5481 m²/g and the order of that is scallop > abalone > cockle. All shells of cockle, abalone, and scallop had no As removal effect by adsorption and precipitation as pH increased. Pb was removed by all shell samples at initial reaction. Although the removal efficiency of Cd and Zn were depending on the reaction medium, that was increased in order of scallop > abalone > cockle. Heavy metal removal efficiency tends to be slightly higher for heated samples than with the raw materials, and higher as the specific surface area is larger.

• Journal of the Mineralogical Society of Korea
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• v.29 no.1
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• pp.1-10
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• 2016

We studied the heavy minerals in 46 surface sediments collected from the Central Yellow Sea Mud (CYSM) to characterize the type, abundance, mineralogical properties and distribution pattern using the stereo-microscopy, field-Emission scanning electron microscopy (FE SEM) and chemical analysis through the energy dispersive spectrometer (EDS). Heavy mineral assemblages are primarily composed of epidote group, amphibole group, garnet group, zircon, rutile and sphene in descending order. Epidote group and amphibole group minerals account for more than 50% of total heavy minerals. The minerals in epidote group, amphibole group and garnet group in studied area are epidote, edenite and almandine, respectively. When we divided the CYSM into two regions by $124^{\circ}E$, the eastern region contain higher contents of epidote and (zircon + rutile), which are more resistant to weathering but lower of amphibole, which is less resistant to weathering than the western region. Based on this results, it is possible to estimate that the eastern region sediments are transported for a long distance while western region sediments are transported for a short distance from the source area. In the future, the additional study on the heavy minerals in river sediments flowing into the Yellow Sea and much more samples for marine sediments must be carried out to interpret exactly the provenance and sedimentation process.