Pierwiastki ziem rzadkich (REE) w iłowcach z wybranych pokładów węgla kamiennego serii mułowcowej i piaskowcowej Górnośląskiego Zagłębia Węglowego

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, Fe₂O₃ and K₂O were observed. Whatever the petrographic character of the claystone rocks, among the analyzed rare earth elements, the highest participation of Ce, La, Y, N d and Sc were found. O ther 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 N d, 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/Al₂O_{3and increased content of} P₂O₅, ignition loss and Fe₂O₃ were taken into account. Most of the elements analyzed in group of rocks distinguished byincreased content of P₂O₅ and 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 sideriteclaystone are characterized by the highest values of correlation coefficients of rare earth elements with Fe₂O₃.