THE VARIABILITY IN THE CONTENT OF RARE EARTH ELEMENTS (Ce, La, Sc, and Y) IN BITUMINOUS COAL (LUBLIN COAL BASIN).

Rare earth elements form the group of 15 elements from the lanthanide group (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) and two elements from the scandium group (Sc and Y). The lanthanide group can be divided into two subgroups: Light Rare Earth Elements (LREE) and Heavy Rare Earth Elements (HREE). The variability of the content was determined for LREE (Ce - cerium, lanthanum - La) and elements from the scandium group (Sc - scandium, Y - yttrium). The analyzed samples of bituminous coal were collected from the Bogdanka deposit of the Lublin Coal Basin (LCB). The Lublin Coal Basin is located in the central-eastern part of Poland. The variability in the content of the analyzed rare earth elements (Ce, La, Sc, and Y) in bituminous coal has been shown to be high. The lowest variability was recorded for scandium and the highest for lanthanum and cerium, while in the case of yttrium the variability was average. The coefficient of asymmetry of scandium indicates a positive quasi-asymmetry of the distribution, while the probability distribution of the remaining elements is characterized by a weak asymmetry. The correlation analysis has shown high statistically significant relationships between the following pairs of elements: Ce - La, Ce - Y, and La - Y. The confirmed correlations are probably related to diadochical substitution in monazite. The preliminary analysis of the REE content has shown that concentrations of elements in coal samples from the LCB are slightly lower than the Clarke values for bituminous coals worldwide. In the case of La and Sc, the studies have confirmed the highest concentrations of the examined elements in the seam No. 385, while the lowest for the seam No.391. The maximum concentrations of all analyzed elements were recorded at the floor of the No. 385/2 seam. Therefore, the authors suggest that further research is needed to determine whether the No. 385/2 seam is interesting from the point of view of the feasibility and profitability of the future recovery of rare earth elements. [ABSTRACT FROM AUTHOR]