Abundance and geological implication of rare earth elements and yttrium in coals from the Suhaitu Mine, Wuda Coalfield, northern China

Abstract

Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the concentrations of rare earth elements and yttrium (REY) in coal and associated rock samples from the Suhaitu Mine, Wuda Coalfield, Northern China. The concentration of REY in the No. 15 coal of the Suhaitu Mine is lower than that in normal Chinese coal, but is slightly higher than that in normal world hard coal. The roof and some partings of the No. 15 coal have been leached by ground water. The geochemical patterns of REY indicate that the LREY-HREY have been slightly fractionated, which may be related to the homogenization of rare earth elements and yttrium in seawater. The REY distribution patterns for most of coal benches of the No. 15 coal are of H-REY type or H-M-REY type. This may be attributed to the influence of seawater and stronger organic affinity of the HREY than that of the LREY. The correlations of REY concentration and the ash yield indicate that REY in the No. 15 coal are associated with clay minerals and REY-bearing organic compounds.