نتایج جستجو برای: rare earth elements ree

تعداد نتایج: 590324  

2018
Sirio Consani Tonci Balić-Žunić Anna Maria Cardinale Walter Sgroi Gabriele Giuli Cristina Carbone

A synthetic Cu-Al-SO₄ layered double hydroxide (LDH), analogue to the mineral woodwardite [Cu1-xAlx(SO₄)x/2(OH)₂·nH₂O], with x < 0.5 and n ≤ 3x/2, was synthesised by adding a solution of Cu and Al sulphates to a solution with NaOH. The pH values were kept constant at 8.0 and 10.0 by a continuous addition of NaOH. The material obtained had poor crystallinity, turbostratic structure, and consiste...

Journal: :Geochemistry International 2022

Abstract This paper is dedicated to the isotope-geochemical study of zircon from riebeckite granites Verkhnee Espe rare earth-rare metal deposit and specification its U–Pb age. Zircon massif peculiar in high content non-formula elements (up 43000 ppm REE, up 22000 Y, others) demonstrates a clearly expressed heterogeneous structure. The central rim zones show “magmatic” rare-earth element (REE) ...

2015
F. B. Denny R. N. Guillemette

The rare earth elements (REE) are composed of the Lanthanide Series of 15 elements with atomic numbers (57) through (71) and yttrium (39). Because of their geochemical behavior, REE rarely form their own minerals and more commonly are found incorporated within the structure of other minerals. There is growing concern over the economical availability of REE because of their diverse and expanding...

Journal: :Environmental science & technology 2012
Elisa Alonso Andrew M Sherman Timothy J Wallington Mark P Everson Frank R Field Richard Roth Randolph E Kirchain

The future availability of rare earth elements (REEs) is of concern due to monopolistic supply conditions, environmentally unsustainable mining practices, and rapid demand growth. We present an evaluation of potential future demand scenarios for REEs with a focus on the issue of comining. Many assumptions were made to simplify the analysis, but the scenarios identify some key variables that cou...

2011
Xiaoyue Du T. E. Graedel

The rare earth elements (REE) are a group of fifteen elements with unique properties that make them indispensable for a wide variety of emerging, critical technologies. Knowledge of the life cycles of REE remains sparse, despite the current heightened interest in their future availability. Mining is heavily concentrated in China, whose monopoly position and potential restriction of exports rend...

2016
Steven R. Izatt James S. McKenzie Neil E. Izatt Ronald L. Bruening Krzysztof E. Krakowiak Reed M. Izatt

Separation methods for rare earth elements (REE) are predominantly based on solvent extraction procedures. These methods are low in metal selectivity and generate large amounts of waste resulting in high capex and opex costs. Molecular Recognition Technology (MRT) is a much simpler green chemistry process that uses no organic solvents and carries out separations with highly metal-selective Supe...

2017
Marc Ulrich Sarah Bureau Catherine Chauvel Christian Picard

This study reports precise and accurate data for rare earth elements (REE) measured on eight geological reference materials, five enriched in REE (BE-N, BHVO-2, BR, BR-24 and RGM-1) and three very depleted in REE (BIR-1, UB-N and DTS-2). Data were acquired by quadrupole ICP-MS after isolation of the REE using an ion-exchange chromatography procedure. All the measured REE abundances are similar ...

2011
Nathan Henderson

Aldrich brand products are sold through Sigma-Aldrich, Inc. Sigma-Aldrich, Inc. warrants that its products conform to the information contained in this and other Sigma-Aldrich publications. Purchaser must determine the suitability of the product for its particular use. See reverse side of invoice or packing slip for additional terms and conditions of sale. All prices are subject to change witho...

2017
Cheng Xu Jindřich Kynický Martin P. Smith Antonin Kopriva Martin Brtnický Tomas Urubek Yueheng Yang Zheng Zhao Chen He Wenlei Song

Heavy rare earth elements (HREE) are dominantly mined from the weathering crusts of granites in South China. Although weathering processes occur globally, no economic HREE resources of this type have yet been found outside China. Here, we report the occurrence of unidentified REE minerals in the granites from South Chinese deposits. They contain high levels of both HREE and light REE, but are s...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2006
Yali Sun Min Sun Guochun Zhao

This study developed a methodology to analyze trace rare earth elements (REEs) in geological materials by capillary electrophoresis (CE). Changed from dilute HNO3 into a water medium by heating, REE ions are detectable at approximately 2 ng mL(-1). In the presence of coexisting elements from geological samples, REE separations were carried out. After sample fusion with Na2O2 and interference se...

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