Economic and Environmental Geology

Table. 1.

Table. 1.

Average and highest content of REE in world coals (modified after Seredin & Finkelman, 2008)

Element Average content(ppm) Highest content
UCC Sedimentary rocks World coals Coal(ppm) Ash(%)
Brown Hard All
Y 22 29 8.6 8.2 8.4 1160 0.37
La 30 32 10 11 11 371 0.26
Ce 64 52 22 23 23 700 0.37
Pr 7.1 6.8 3.5 3.4 3.5 6.5 0.06
Nd 26 24 11 12 12 230 0.3
Sm 4.5 5.5 1.9 2.2 2 60 0.09
Eu 0.9 0.94 0.50 0.43 0.47 15.2 0.023
Gd 3.8 4 2.6 2.7 2.7 113 0.12
Yb 0.6 0.69 0.32 0.31 0.32 21 0.02
Dy 3.5 3.6 2.0 2.1 2.1 139 0.12
Ho 0.8 0.92 0.50 0.57 0.54 31 0.02
Er 2.3 1.7 0.85 1.00 0.93 93 0.07
Tm 0.3 0.78 0.31 0.30 0.31 13.7 0.01
Yb 2.2 2 1.0 1.0 1 91 0.08
Lu 0.3 0.44 0.19 0.20 0.2 30.2 0.01
Econ. Environ. Geol. 2022;55:241-59 https://doi.org/10.9719/EEG.2022.55.3.241
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