• Title/Summary/Keyword: 희토류 원소

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Sorption Behavior of $^{241}Am,\;^{152}Eu,\;^{160}Tb\;and\;^{60}Co$ in the Geological Materials: Eu as an Optimum Analogue for Fate and Transport of Am Behavior in Subsurface Environment (지질매체내에서의 $^{241}Am,\;^{152}Eu,\;^{160}Tb,\;^{60}Co$의 흡착특성비교: 지표지질내에서의 Am의 거동특성을 위한 최적 유사체로서의 Eu)

  • Lee, Seung-Gu;Lee, Kil-Yong;Cho, Soo-Young;Yoon, Yoon-Yeol;Kim, Yong-Je
    • Economic and Environmental Geology
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    • v.40 no.4
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    • pp.361-374
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    • 2007
  • Rare earth elements(REEs) have been used as an useful tool in understanding the various geological processes such as evolution and differentiation in the crust. The REEs also have been used as an analog of actinides for radioactive wastes at the water-rock interactions. Using physicochemical properties of the REEs and actinides, we have shown that Eu is an optimum analogue for understanding the behavior of Am in subsurface environments. Factors affecting sorption behavior of radioactive nuclides in groundwater were investigated by batch experiments. Four nuclides such as $^{241}Am,\;^{152}Eu,\;^{160}Tb\;and\;^{60}Co$ were selected to test our hypothesis, and $^{160}Tb$ and $^{60}Co$ were specifically used to compare to the sorption behavior between $^{241}Am-^{152}Eu$ and other radioactive nuclides. Four different rock samples and one groundwater were used in the batch experiments where solution pH for all experiments was fixed at 5.5. Our results demonstrate that $^{241}Am,\;^{152}Eu,\;and\;^{160}Tb$ show similar sorption behavior whereas $^{60}Co$ is different in sorption behavior at the mineral-water interface, suggesting that the sorption behavior of $^{60}Co$ is affected by different rock types. Our results also show that 1) Eu in REEs is optimum analogue of fate and transport of Am in subsurface environments, and 2) mineral compositions such as $SiO_2,\;TiO_2,\;P_2O_5$ and distribution of REEs such as Eu anomaly play key roles in affecting sorption behavior of radioactive nuclides even though physicochemical properties of geological materials such as specific surface area and cation exchange capacity can not be ruled out.

Decomposition and leaching of Rare earth ore (희토류 광물의 분해 및 침출)

  • Lee, Jin-Yeong;Jeon, Ho-Seok;Kim, Joon-Soo
    • Mineral and Industry
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    • v.23
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    • pp.26-31
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    • 2010
  • 희토류 정광으로부터 첨단산업 원료소재로 수요가 급증하고 있는 고순도 희토류 소재를 제조하기 위한 가장 첫 공정은 침출공정이다. 즉, 희토류 정광으로부터 원소별 희토류 성분을 분리하기 위해서는 용액상태로 전환이 필요한데, 이때 일반적인 산 및 알카리 용액에는 희토류 성분은 침출이 되지 않으므로 강산 또는 강 알카리 조건에서 희토류 정광을 침출 가능한 형태로 변환 시켜주는 분해공정이 선행되며 이후 산 침출에 의해 희토류 성분을 침출하게 된다. 본 고에서는 대표적인 희토류 광물인 모나자이트와 바스트나사이트, 그리고 이 광물의 혼합물 형태로 생산되는 혼합광물에 대한 분해 및 침출공정을 소개하고자 한다.

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Effect of Zircon on Rare-Earth Element Determination of Granitoids by ICP-MS (ICP-MS를 이용한 화강암내 희토류원소 분석시 저어콘이 미치는 영향)

  • Lee, Seung-Gu;Kim, Taehoon;Han, Seunghee;Kim, Hyeon Cheol;Lee, Hyo Min;Tanaka, Tsuyoshi;Lee, Seung Ryeol;Lee, Jong Ik
    • The Journal of the Petrological Society of Korea
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    • v.23 no.4
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    • pp.337-349
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    • 2014
  • We measured rare earth element and Zr concentrations of USGS granite standard material GSP-2 and GSJ granite standard material JG-1a to clarify the effect of zircon during rare earth element analysis using ICP-MS. We also measured rare-earth element and zirconium (Zr) contents of zircon from granite by acid-digestion methods using conventional teflon vial and pressure-bomb. The results show that acid-digestion using teflon vial dissolved ca. 50% of zircon compared to pressure-bomb method. The Zr contents of JG-1a and GSP-2 gave ca 50% of reference value. However, rare-earth element abundance of JG-1a and GSP-2 were similar to those of reference values. This suggests that the decomposition degree of zircon might give a negligible effect on a petrological and geochemical interpretation using chondritenormalized REE pattern.

Assessments of Dissolved Rare Earth Elements and Anthropogenic Gadolinium Concentrations in Different Processes of Wastewater Treatment Plant in Busan, Korea (부산 하수처리장에서 공정별 용존 희토류 원소의 농도 및 인위적 기원 가돌리늄의 배출량 평가)

  • Lim, Ijin;Ryu, Jong-Sik;Lee, Joonyeob;Lee, Jun-Ho;Cho, Hyung-Mi;Kim, Taejin
    • Journal of the Korean earth science society
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    • v.43 no.2
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    • pp.303-311
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    • 2022
  • Gadolinium, commonly used as a contrast agent for magnetic resonance imaging (MRI), is discharged into aquatic environments without removal after treatment in wastewater treatment plants (WWTPs) because of its high stability. In this study, we collected water samples from Suyeong WWTP, Busan, to investigate the dissolved rare earth element (REE) removal capacity of each wastewater treatment process and to evaluate the discharge of anthropogenic Gd (Gdanth) from effluents. As wastewater passed through each stage of treatment, the concentrations of light REEs (La-Eu) decreased, whereas those of heavy REEs (Tb-Lu) were relatively consistent. Negative Sm anomalies (<1) were observed in several samples, indicating that Sm can be removed by adsorption onto particles or phosphate during the biological removal process. Positive Gd anomalies (149±50, n=9) were observed in all samples. The ratios of Gdanth concentrations to measured Gd concentrations in all wastewater treatment processes were higher than 97%. This indicates that Gdanth was discharged to the Suyeong River without removal during the wastewater treatment process. Considering the daily treatment capacity in each process, the total flux of Gdanth was estimated to be 259 mmol/day. Our results suggest that mid- and/or long-term monitoring of Gd is needed because Gdanth is continuously discharged into Suyeong Bay through WWTPs.

Geochemistry and Sm-Nd isotope systematics of Precambrian granitic gneiss and amphibolite core at the Muju area, middle Yeongnam Massif (영남육괴 중부 무주 지역에 위치하는 선캠브리아기 화강편마암 및 앰피볼라이트 시추코아의 Sm-Nd 연대 및 지구화학적 특징)

  • Lee Seung-Gu;Kim Yongje;Kim Kun-Han
    • The Journal of the Petrological Society of Korea
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    • v.14 no.3 s.41
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    • pp.127-140
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    • 2005
  • The Samyuri area of Jeoksang-myeon, Muju-gun at the Middle Yeongnam Massif consists of granitic gneiss, porphyroblastic gneiss and leucocratic gneiss, which correspond to Precambrian Wonnam Series. Here we discuss a geochemical implication of the data based on major element composition, trace element, rare earth element (REE), Sm-Nd and Rb-Sr isotope systematics of the boring cores in the granite gneiss area. The boring cores are granitic gneiss (including biotite gneiss) and amphibolite. The major and trace element compositions of granitic gneiss and amphibolite suggest that the protolith belongs to TTG (Tonalite-Trondhjemite-Granodiorite) and tholeiitic series, respectively. Chondrte-normalized REE patterns vary in LREE, HREE and Eu anomalies. The granitic gneiss and amphibolite have Sm-Nd whole rock age of $2,026{\pm}230(2{\sigma})$ Ma with an initial Nd isotopic ratio of $0.50979{\pm}0.00028(2{\sigma})$ (initial ${\epsilon}_{Nd}=-4.4$), which suggests that the source material was derived from old crustal material. Particularly, this initial ${\epsilon}$ Nd value belongs to the range of the geochemical evolution of Archean basement in North-China Craton, and also corresponds to the initial Nd isotope evolution line by Lee et al. (2005). In addition, chondrite-normalized REE pattern and initial Nd value of amphibolite are very similar to those of juvenile magma in crustal formation process.

Spectrophotometric Determination of Rare Earths by Ternary Complex Formation with MTB and Surfactant (글로방전 발광분광법에 의한 란탄족 원소의 정밀 분석. MTB와 계면활성제의 삼성분 착물 형성에 의한 희토류 원소의 분광광도법 정량에 관한 연구)

  • Cha Ki-Won;Yun Jeong-Sook;Kim Kyung-Hwan;Ha Young-Gu;Kim Ha-Suek
    • Journal of the Korean Chemical Society
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    • v.37 no.5
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    • pp.496-502
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    • 1993
  • Spectrophotometric determination of rare earth elements with MTB and the composition ratio were investigated in the presence of surfactants of cetylpyridinium chloride (CPC), Triton X-100, dodecyltrimethylammonium bromide (DTMAB) and cetyltrimethylammonium bromide (CTMAB) at pH 6.5. The colour development between MTB and rare earths in the presence of cationic surfactants was very stable and more sensitive than that in the absence of surfactants. The largest absorbance increase was provided by CPC, which was therefore chosen for determination of rare earth elements. REE-MTB-CPC complex has absorption maxima at 650 nm and obeys the Beer's law in the range of 0∼100 ng/ml. Molar absorptivity is $6.6{\sim}9.4{\times}10^4\;mol^{-1}l\;cm^{-1}$.

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A Study on the Correction of Spectral Line Overlaps for the Determination of Rare Earth Elements by X-Ray Fluorescence Spectrometry (X-선 형광분광법에 의한 희토류원소 분석에서 스펙트럼선 겹침 방해의 보정에 관한 연구)

  • Young-Man Kim;Young-Sang Kim;Yoon-Chang Park;Chong-Wook Lee
    • Journal of the Korean Chemical Society
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    • v.30 no.6
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    • pp.538-547
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    • 1986
  • The 8 rare earth elements were determined in the monazite concentrates by X-ray fluorescence spectrometry. The spectral line overlapping interferences from the other elements were investigated and the correction methods of interferences were studied using line overlap coefficients. The coefficients were calculated from the ratios of the intensities measured at the diffracted angle (2${\theta}$) of the analytical lines of other elements to the intensity of pure rare earth oxide. The coefficients were used to correct the line overlaps by a regression analysis. The linearities of calibration curves from the corrected intensities were remarkably improved, and their standard deviations were decreased. The analytical results agreed with that of the inductively coupled plasma(ICP) spectrometry within an allowable error range.

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Fluorescence Signal Analysis of Mixed Rare Earth Elements by Nonlinear Fitting Method (비선형 Fitting법에 의한 희토류 혼합물의 형광신호 분석)

  • Kim, Dukhyeon;Shin, Jangsoo;Song, Kyuseok;Cha, Hyungki;Lee, Jongmin
    • Analytical Science and Technology
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    • v.8 no.1
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    • pp.41-45
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    • 1995
  • To analyze mixed rare earth elements quantitatively a nonlinear fitting method was applied to laser induced fluorescence signals. Mixed flourescence signal of two elements, Sm and Eu were resolved independently and determined the concentration of these two elements simultaneously. It was found that detection limit for each element in the mixture was sub-ppb level which was the same as that of the single element sample. Additionally it was found that lifetimes of Sm and Eu extracted from the nonlinear fitting method is the same as in the single element cases.

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Geochemistry of the Major and Trace Elements in a Soil Profile of the Hyangdeung Area, Gwangju City, Korea (광주광역시 향등지역의 토양단면에서 주성분원소 및 미량성분원소의 지화학적 특성)

  • Shin, In-Hyun;Ahn, Kun-Sang;Kang, Jong-Hyun
    • Journal of the Korean earth science society
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    • v.26 no.8
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    • pp.800-808
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    • 2005
  • Elemental mobility during the weathering of granite in the Gwangju Hyangdeung area was investigated using ICP-MS analysis. It appeared that Al, Fe, Ti, K were lost from the profile, whereas Si, Ca, Na Mg, P and Mn were immobile during chemical weathering. In less weathered soil, large enrichment of K and Ti were found relative to Al, whereas other elements such as Si, Ca, Na, Mg and P are deplete. Fe content is constant throughout the weathered profiles. Amounts of Rb, Sr, Y, Cs, Pb, Th and U increased toward the surface. Nb, and Co have accumulated in the deepest parts of the weathered soil profile. These results agree with similar published studies. In addition, the analytical data shows that Ba and Ga increased, while Cu, Zn, Cr and Ni were relatively constant in this area. REE tend to increase in most samples, while LREEs, relative to Al, were enriched in the lower and upper saprolite. HREEs were enriched in the lower and upper saprolite.

Rare Earth Element Analysis with Chromatography-Inductively Coupled Plasma Atomic Emission Spectrometry and the Comparison of Cross Flow and Ultrasonic Nebulizers (크로마토그래피-유도 결합 플라스마 원자방출 분광법을 이용한 희토류 원소들의 연속적 분석 및 직교형과 초음파분무기의 비교)