• Title/Summary/Keyword: rare earth element

Search Result 115, Processing Time 0.12 seconds

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
    • /
    • v.23 no.4
    • /
    • pp.337-349
    • /
    • 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.

Study on the Precision Analysis of Lanthanides by Atomic Emission Spectroscopy (I). Separation of Rare Earth Elements Using Ln-EDTA Eluent (원자발광광도법에 의한 란탄족 원소의 정밀분석에 관한 연구 (제 1 보) 희토류-EDTA 용리액에 의한 희토류 원소의 분리 회수)

  • Cha Ki-Won;Oh Jin-Hee;Ha Young-Gu;Kim Ha-Suck
    • Journal of the Korean Chemical Society
    • /
    • v.36 no.5
    • /
    • pp.692-696
    • /
    • 1992
  • $NH_4^+ form cation exchange resin was used to separate one rare earth element from the rare earth mixture solution using Ln-EDTA eluent. Rare earth mixture solution was passed through the resin bed and eluted with 0.1M La-EDTA solution as an eluent. In here all the rare earth element except lanthanum ion are eluted and lanthanum ion absorbed in resin bed is eluted using 0.1M EDTA solution. If Ce-EDTA solution instead of La-EDTA solution was used as an eluent, all the rare earth element except cerium ion are eluted and cerium ion is eluted with 0.1M EDTA solution. This method can be applied to separate the individual rare earth element from the mixture. The separation mechanism is as follows: Absorption : 3RNH_4 + Ln^{3+} = R_3Ln + 3NH_4^+, La-EDTA elution : R_3Ln + La-Y- = R_3La + Ln-Y-, EDTA elution : R_3La + HY^3- = La_-Y + RH + 2R^-.$

  • PDF

A Study on Addition of Rare Earth Element in the Spent Permanent Magnet Scrap to Gray Cast Iron (회주철에서의 폐 영구자석 스크랩을 활용한 희토류 원소 첨가 영향 연구)

  • Park, Seung-Yeon;Noh, Jung-Hyun;Kim, Hyo-jung;Lim, Kyoung-Mook
    • Resources Recycling
    • /
    • v.27 no.3
    • /
    • pp.48-57
    • /
    • 2018
  • In this study, we developed a method for manufacturing high strength gray cast irons by adding a rare earth element (R.E.) included in a spent permanent magnet scrap to gray cast irons. The improvement of the mechanical properties of gray cast irons is attributed to A-type graphite formation promoted by complex sulfide, which was formed by R.E. in the spent magnets during a solidification process. The cast specimen inoculated by R.E. in the spent magnet scrap showed excellent tensile strength up to 306 MPa, and is similar to that of the specimen inoculated by expensive misch-metal. In this regards, we concluded that the cheap spent magnets scrap is a very efficient inoculation agent in fabrication of high performance gray cast irons.

Co-doping Effects on the Blue Up-conversion Characteristics of Fluoride Glasses (희토류 원소의 복합첨가에 의한 fluride 유리에서의 청색 상향전이현상)

  • 류선윤
    • Journal of the Korean Ceramic Society
    • /
    • v.37 no.1
    • /
    • pp.33-43
    • /
    • 2000
  • Up-conversion of rare-earth element added glass is promising area for short wavelength laser source by utilizing high power semiconductor infra-red laser if the efficiency can be increased by proper method. In this study, relatively low phonon energy fluoride glasses were prepared by co-doping rare-earth elements to realize the high efficiency up-convertor. The physical, chemical, andoptical properties of co-doped fluoride glasses were measured. 10 combinations of 5 different rare-earth fluoride elements doped samples were prepared and their transition temperatures, chemical durability, density, hardness, refractive index, absorption, fluorescence, and fluorescence lifetime were measured. 480nm wavelengths blue up-conversion was found in the Yb3+/Tm3+ co-doped glass sample with 800nm laser source and the optimum composition for the most efficient blue up-conversion was found from the glass sample with 0.3 mol% TmF3 and 1 mol% YbF3.

  • PDF

Abundane of Rare Earth Element in Duwon Meteorite and Its Geochchemical Significance (두원운석의 희토류원소 존재도 및 지구화학적 의의)

  • Lee Seung-Gu;Kim Kun-Han;Choi Byeon-Gak
    • The Journal of the Petrological Society of Korea
    • /
    • v.13 no.4
    • /
    • pp.238-243
    • /
    • 2004
  • Duwon meteorite was fallen on 23 November 1943 in Duwonmyeon, Goheung, Jeolanam-Do. We measured rare earth element abundance of Duwon meteorite by isotope dilution thermal ion mass spectrometry (ID-TIMS) and ICP-MS. As a result, except La and Ce, abundance of other rare earth element show a correspondence within 10% of error range. However, La and Ce show more than 70% in abundance, which is considered due to 1) experimental procedure or 2) inhomogeneity of sample. Leedey meteorite was fallen on 25 November 1943 in Dewey County, Oklahoma, USA. which suggested that fallen difference between Leedey and Duwon meteorites is only 2 days. Leedey and Duwon meteorites are classified as ordinary chondrite of L6 type. In Leedey chondrite-normalized REE pattern, Duwon meteorite shows nearly flattened, which suggests close relationship between Leedey and Duwon meteorites meteoritically or cosmochemically.

Geochemical Implication of Rare Earth Element from Yellow sand (Asian Dust) at Daejeon Area, Korea: A Preliminary Study for Clarifying Source Area of Yellow Sand (대전지역 황사(아시아 먼지)내 희토류원소 분포도의 지구화학적 특성-근원지 규명을 위한 초기연구)

  • Lee, Seung-Gu;Youm, Seung-Jun
    • The Journal of the Petrological Society of Korea
    • /
    • v.17 no.1
    • /
    • pp.44-50
    • /
    • 2008
  • A geochemical technique based on rare earth element geochemistry was used to clarity the source of the Asian dust (Yellow sand) in the Daejeon area. The Asian dusts were collected 4 times during 31th March- 2nd April and 25th May-27th May 2007. The Yellow sand shows PAAS (Post Archean Australian Shale)-normalized REE pattern of the flattened LREE and slightly depleted LREE without Eu anomaly, whereas the Daejeon soil has slightly enriched LREE and depleted HREE with negative Eu anomaly. Our results show that REE patterns of the Asian dust are LREE-flattened similar to those of the sediment from the south-eastern part of Ordos desert. This suggests that Asian dust in the Daejeon area might be derived from the south-eastern part of Ordos desert.

Evaluation of Effects of Rare Earth Element and Cooling Rate on the Eutectic Reaction of Flake Graphite Cast Irons by Cooling Curve Analysis (냉각곡선 분석을 통한 편상흑연주철의 공정반응에 미치는 희토류원소 및 냉각속도의 영향 평가)

  • Lee, Sang-Hwan;Park, Seung-Yeon;Lee, Sang-Mok;Kim, Myung-Ho
    • Journal of Korea Foundry Society
    • /
    • v.33 no.1
    • /
    • pp.13-21
    • /
    • 2013
  • The effects of rare earth element (R.E.) and cooling rate on the eutectic reaction of flake graphite cast irons were studied by combined analysis of macro/micro-structure and cooling curve data. The correlation between eutectic reaction parameter and macro/micro-structure was systematically investigated. Two sets of chemical compositions with the different addition of R.E. were designed to cast. Three types of molds for cylindrical specimens with the different diameters were prepared to analyze cooling rate effect. The difference between undercooling temperature and cementite eutectic temperature (${\Delta}T_1=T_{U}-T_{E,C}$), which is increased by adding R.E. and decreased by increasing cooling rate, is considered to be a suitable eutectic reaction parameter for predicting graphite morphology. According to the criterion, A-type graphite is mainly suggested to form for ${\Delta}T_1$ over $20^{\circ}C$. Eutectic reaction time (${\Delta}t$), which is decreased by adding R.E. or increasing cooling rate, is a suitable eutectic reaction parameter for predicting eutectic cell size. Eutectic cell size is found to decrease in a proportion to the decrease of ${\Delta}t$.

Study on Characteristics of Sn-0.7wt%Cu-Xwt%Re Solder (Sn-0.7wt%Cu-Xwt%Re 솔더의 특성에 관한 연구)

  • Noh, Bo-In;Won, Sung-Ho;Jung, Seung-Boo
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.14 no.4
    • /
    • pp.21-25
    • /
    • 2007
  • In this study, the properties of Sn-0.7wt%Cu-Xwt%Re(X=$0.01{\sim}1.0$) older were investigated by using DSC(differential scanning calorimetry), wetting balance, victors hardness and tensile testers. The melting temperature of solder was increased with increasing the contents of rare earth element, and the melting temperature range of Sn-0.7Cu-($0.01{\sim}1.0$)Re solder was $233.9{\sim}234.7^{\circ}C$. The wettability with Sn-0.7Cu-0.1Re solder was higher than that of Sn-0.7Cu-0.01Re and Sn-0.7Cu-1.0Re solders, and the wettability of Sn-0.7Cu-0.1Re solder was higher than that of Sn-0.7wt%Cu-0.01w%P solder. Also, the hardness and tensile strength of solder were increased with increasing the contents of rare earth element.

  • PDF

A Role of Standard Material in Rare Earth Element Analysis by ICP-MS (ICP-MS를 이용한 희토류원소 분석시 표준시료의 선택이 미치는 영향)

  • Lee Seung-Gu;Kim Kun-Han;Song Yong Sun;Kim Yongje
    • The Journal of the Petrological Society of Korea
    • /
    • v.14 no.4 s.42
    • /
    • pp.237-250
    • /
    • 2005
  • In order to clarify the effect of standard rock material in the chemical analysis of rare earth element abundance with ICP-MS, we measured rare earth element abundance of KIGAM granite standard rock material (KG-1), USGS granite standard rock material (G-2), GSJ granite standard rock materials (JG-1a and JG-2). In REE analysis, we used conventional calibration standard solutions, KG-1, JG-1a, JG-2 and G-2 as standard material, respectively. Chondrite-normalized LREE patterns of low granite standard material correspond well each other in the recommended value and the estimated value regardless of a kind of standard rock. However, the HREE patterns of the estimated value based on G-2 or JG-2 and the recommended value are different from each other. Such difference may be due to the wrong recommended value or a specific geochemical properly of the standard rock material itself, The chondrite-normalized REE patterns of four standard rock materials estimated on the basis of KG-1 or JG-1 a show little deviation compared to the those of the recommended values. This suggests that KG-1 and JG-1a may be a optimum standard material for granitoids.