Rare Earth Elements (REE) in Claystones with Selected Coal Seams of the Mudstone and Sandstone Series of the Upper Silesian Coal Basin

In this paper results of investigation on the variability of REE contents in the clayey rocks accompanying selected coal seams from Zaleskie and Ruda beds of western part of Upper Silesia Coal Basin (USCB) have been presented. 75 samples have been analysed from the claystones coexisting with coal seams 405 and 408 collected from the USCB area. Contents of selected REE have been assessed with a use of the Instrumental Neutron Activation Analysis (INAA). In regard to the constraints of this method following elements underwent evaluation: scandium (Sc), lanthanum (La), cerium (Ce), neodymium (Nd), samarium (Sm), Europium (Eu), terbium (Tb), ytterbium (Yb), and lutetium (Lu). Contents of yttrium (Y) was determined with a use of the Fusion-Inductively-Coupled Plasma (FUSICP) method.In all featured groups of claystone (claystone, sandy claystone and siderite claystone) the highest, although diverse content of SiO2, Al2O3, Fe2O3and K2O were observed. Whatever the petrographic character of the claystone rocks, among the analyzed rare earth elements, the highest participation of Ce, La, Y, Nd and Sc were found. Other analyzed REE showed significantly lower content. Some regional diversity of REE in the area of study was also observed. In the south-western part of the USCB, higher participation showed: Y, Sm and Nd, while in the north-western part: Sc. To determine the dependence between content of rare earth elements and chemical composition, the correlation-coefficients were calculated. In the calculations ratio SiO2/Al2O3and increased content of P2O5, ignition loss and Fe2O3were taken into account. Most of the elements analyzed in group of rocks distinguished by increased content of P2O5and ignition loss, showed high positive correlation with chemical composition. In almost all groups of rocks negative correlation with MnO, loss on ignition and sometimes with CaO was found. Rocks represented by siderite claystone are characterized by the highest values of correlation coefficients of rare earth elements with Fe2O3.