PDF Publication Title:
Text from PDF Page: 173
REE Mineralogy and Resources Chapter 279 137 where C is concentration, subscript i refers to an element and superscripts a and b refer to a- and b-phases, respectively. The partitioning coefficients are related to the pressure, temperature, chemical composition, and oxygen fugacity of the melts or fluids. These coefficients have been estimated by numerous experiments, chemical analyses of natural materials, and theoretical calculations. Although the partitioning coefficients of the REEs are affected by various factors mentioned earlier, it is useful to compare the coefficients of representa- tive minerals in the igneous rocks (for example, basalt) for understanding of the behavior of the REEs. White (2013) compiled the mineral–melt partition coefficients of REEs for mafic magmas, based on the data assembled in Geo- chemical Earth Reference Model (GERM, www.earthref.org/GERM; Fig. 3). These results show that the coefficients of clinopyroxene, garnet, plagioclase, and amphibole are much higher than those of olivine and spinel, and the minerals with the high partitioning coefficients control the concentration of REEs. Although olivine is the most abundant mineral in the upper mantle, the partitioning of REEs is not significantly affected because of its low coefficients. Among REEs, europium is highly partitioned to plagioclase because diva- lent (Eu2+) europium in relatively reducing conditions substitutes for Ca2+ in 101 10−0 10−1 10−2 10−3 10−4 10−5 Clinopyroxene Amphibole Plagioclase Spinel FIG. 3 10−6 REE mineral-melt partition coefficients for mafic magmas after White (2013). La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Garnet Mineral–melt partition coefficient Or thopyroxene OlivinePDF Image | HANDBOOK ON THE PHYSICS AND CHEMISTRY OF RARE EARTHS
PDF Search Title:
HANDBOOK ON THE PHYSICS AND CHEMISTRY OF RARE EARTHSOriginal File Name Searched:
Chemistry-Rare-Earths-49.pdfDIY PDF Search: Google It | Yahoo | Bing
Sulfur Deposition on Carbon Nanofibers using Supercritical CO2 Sulfur Deposition on Carbon Nanofibers using Supercritical CO2. Gamma sulfur also known as mother of pearl sulfur and nacreous sulfur... More Info
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)