نتایج جستجو برای: ree elements
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A low-blank, high sensitivity isotope dilution, ICP-MS analytical technique has been used to obtain REE abundance data from single conodont elements weighing as little as 5 mg. Sr isotopes can also be measured from the column eluants enabling Sr isotope ratios and REE abundance to be determined from the same dissolution. Results are comparable to published analyses comprising tens to hundreds o...
The Baba Ali deposit is located about 39 km to the north west of Hamadan city. The syenitic pluton intruded and metamorphosed the diorite host rock producing the skarn deposit. Geochemical considerations indicate that the concentration values of rare earth elements in the syenite and diorite range from 35.4 to 560 ppm. Rare earth elements variation in syenitic, skarn and diorite rock are simil...
Rare earth elements (REE) have been recognised as critical raw materials, crucial for many clean technologies. As the gap between their global demand and supply increases, the search for their alternative resources becomes more and more important, especially for the countries which depend highly on their import. Coal fly ash (CFA), which when not utilised is considered waste, has been regarded ...
Rare earth elements (REE) are either housed in exotic REE minerals that sporadically populate the host rock or they occur as ionic substitutions in the crystal structure of existing rock-forming minerals. The genesis of REEs in carbonatite rocks can result in intricate mineralogical textures between REE minerals, host rock minerals, and minerals formed by later processes. Upfront mineralogical ...
Dissolved rare earth element (REE) concentrations were determined in a 27-month time series of the lower Mississippi River. Overall our results agree with limited previous investigations; i.e., the river shows enrichment of heavy REEs relative to light REEs and also has a significant Ce anomaly. However, the previous investigations relied on only single samples from the river. Our seasonal inve...
Biorecovery of rare earth elements (REE) from wastes and ores is achieved by bacteria using biogenic phosphates. One approach uses an enzyme that biomineralises REE phosphate crystals into the extracellular polymeric matrix (EPM). The enzyme, co-localised in the EPM, provides a continuous phosphate feed into biomineralisation. The bacteria can be immobilised in a column, allowing continuous met...
This research presents data on widespread abnormal accumulations of Trace and Rare Earth Elements in many coal deposits worldwide. There have been many studies on the distribution and geochemistry of REEs in coal. ∑REE content in most coals varies from several µg/g to several hundred µg/g, and the REEs are distributed in minerals although some are associated with organic material in coal. In th...
Trace element profiles for common divalent cations (Sr, Zn, Ba), rare-earth elements (REE), Y, U, and Th were measured in fossil bones and teeth from the c. 25 ka Merrell locality, Montana, USA, by using laser-ablation ICP-MS. Multiple traverses in teeth were transformed into 2-D trace element maps for visualizing structural influences on trace element uptake. Trace element compositions of diff...
The rare earth elements (REE) form the largest chemically coherent group in the periodic table. Though generally unfamiliar, the REE are essential for many hundreds of applications. The versatility and specificity of the REE has given them a level of technological, environmental, and economic importance considerably greater than might be expected from their relative obscurity. The United States...
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