Results 1 to 10 of about 1,919 (210)

Flotation concentration of a xenotime pre-concentrate [PDF]

Minerals Engineering, 1997
Abstract The world market for rare-earths elements is increasing due to the development of new products and applications, resulting in the need for technology to treat deposits having highly complex mineralogy, such as that of Pitinga, AM, Brazil, with estimated reserves of 146,960 t of rare-earths oxides (REO), including Y2O3.
C.A. Pereira, A.E.C. Peres
core   +4 more sources

Monazite and Xenotime in European Rocks

Mineralogical Magazine and Journal of the Mineralogical Society, 1897
As the phosphates of the cerium and yttrium groups, monazite aud xenotime, have proved to be quite widespread microscopic accessories in certain types of Brazilian granites and gneisses, "a batea test has recently been made on a number of hand specimens obtained from the mineral establishment of Dr. F. Krantz, of Bonn, for the purpose of determining if
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An empirical garnet (YAG) – xenotime thermometer

Contributions to Mineralogy and Petrology, 2000
A pronounced negative correlation between the yttrium concentration in garnet ([Y]Grt) and temperature has been observed in xenotime (YPO4)-bearing metapelites from central New England, USA. The [Y]Grt decreases roughly two orders of magnitude (∼5500 to less than 100 ppm Y) over a 150 °C interval. A regression of ln([Y]Grt) against estimated reciprocal
Joseph M. Pyle, Frank S. Spear
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Quantum-Chemical Model of the Minimal Cluster in Xenotime

Russian Journal of General Chemistry, 2021
A quantum-chemical model of the minimal cluster in xenotime has been proposed taking into account the ionic-crystal medium potential. The [YO8]5– cluster includes oxygen atoms from six phosphate anions. Owing to the breaking of the covalent P–O bonds, each oxygen atom contributes one unpaired electron to the cluster.
S. G. Semenov, M. V. Makarova, M. E. Bedrina, A. V. Titov   +3 more
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Crystal chemistry of the monazite and xenotime structures

American Mineralogist, 1995
Monazite and xenotime, the RE(P04) dimorphs, are the most ubiquitous rare earth (RE) minerals, yet accurate structure studies of the natural phases have not been reported. Here we report the results of high-precision structure studies of both the natural phases and the synthetic RE(P04) phases for all individual stable rare earth elements.
Yunxiang Ni, John M. Hughes, Anthony N. Mariano   +2 more
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Apatite, Monazite, and Xenotime in Metamorphic Rocks

Reviews in Mineralogy and Geochemistry, 2002
This chapter focuses on phosphates that are significant in metamorphic rocks. A quick survey of phosphate mineral descriptions at a commercial mineral web-site revealed over 500 phosphate mineral names. Remarkably, only three are common in metamorphic rocks: apatite, monazite, and xenotime, and this chapter is restricted to discussion of these minerals.
F. S. Spear, J. M. Pyle
openaire   +1 more source

On the miscibility gap in monazite–xenotime systems

Physics and Chemistry of Minerals, 2007
The regular solid solution model has been applied to solid solubility in the monazite–xenotime systems and is verified against the available experimental data for LaPO4–YPO4 and CePO4–YPO4 systems. The model is then used to predict the miscibility gaps in a number of other monazite–xenotime systems.
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Microstructural studies and carbochlorination kinetics of xenotime ore

Metallurgical and Materials Transactions B, 2001
In this work, a systematic study of the reaction between xenotime, chlorine, and carbon has been performed. The kinetics of carbochlorination of xenotime raw material (rare-earth elements in phosphate form, REPO4) has been studied over a temperature range from 600 °C to 950 °C. The influences of temperature, partial pressure of chlorine, carbon content,
Marco A. Gimenes, Herenilton P. Oliveira
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Simple method of distinguishing zircon, monazite, and xenotime

Journal of Sedimentary Research, 1963
Abstract The absorption spectra of the three minerals can be rapidly and easily obtained and provide a simple method of identification. Other rare earth compounds may also be identified by their spectra.
O. H. Hering, W. Zimmerle
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Phase transformations in xenotime rare-earth orthophosphates

Acta Materialia, 2013
Abstract Xenotime rare-earth orthophosphates were made with compositions close to the xenotime–monazite phase boundary. Stress-driven phase transformations and their associated deformation mechanisms were characterized for these compositions by extensive conventional and high-resolution transmission electron microscopy.
R.S. Hay, P. Mogilevsky, E. Boakye
openaire   +1 more source