[en] The paper deals with such harmful trace elements as: fluorine, actinides (uranium, thorium) and heavy metals in Polish kaolins and ceramic clays. It has been stated that the content of fluorine and actinides in domestic washed kaolin obtained from kaolinitic sandstone from Maria III deposit is moderate. The fluorine content in raw materials for heavy clay ceramics varies in the range 300-1300 ppm. In comparison to kaolins, the higher amount of this element is caused by illicit character of these clays. The actinide content in these clays - about which one can conclude on the basis of the value of natural radioactivity coefficient f₁ and f₂ - in majority it corresponds to the obligatory Polish criteria. In comparison to other row materials for heavy clay ceramics, the highest concentration of heavy metals (mainly Pb, Zn, Cd) is typical for the Upper Silesian Triassic clays in the vicinity of the Tarnowskie Gory. The clays under consideration lie on the layers of Zn-Pb sulphide ores of the same age. Some leachability of heavy metals (especially Zn) in being observed in clays from the vicinity of Tarnowskie Gory after their firing at 1000 ^oC. (author)

[en] Short communication

[en] Short communication. 1 ref., 1 fig

[en] The instrumental neutron activation analysis (INAA) was applied for determination of minor and trace element contents in some Polish clayey rocks. Lower Silesian kaolins from Wyszonowice near Strzelin and from Wadroze Wielkie near Legnica as well as allite from Kaplonosy (Lublin Coal Basin) were investigated. The contents of 26 elements were determined, including rare earth metals (Sc, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu), actinides (U, Th), alkali metals (Na, K, Rb, Cs) and gold. INAA studies allowed to determine the variability of minor and trace element contents in the weathering profile in 2,5/K borehole in Wyszonowice and in size fractions separated from kaolin of Wadroze Wielkie. When using this method, the effectiveness of chemical and thermal extraction of these elements from allite of Kaplonosy was checked, too. (author)

[en] Some rare earth elements (lanthanum, cerium, neodymium, samarium, europium, terbium, ytterbium, lutetium) have been determined by neutron activation analysis in representative samples of residual and sedimentary Lower Silesian kaolins. The concentrations of these elements in the raw kaolins studied are distinctly diversified by, among other factors, the petrographic type of the parent rocks. The most important mechanisms of concentration of rare earth elements were identified as: diadochic substitution in some accessory (mainly zircon) and secondary (phosphates of crandallite group) minerals; and sorption on kaolinite surfaces. (author)

[en] Instrumental neutron activation analysis has been applied for the determination of trace elements in a sample of allite from Kaplonosy and in products of its chemical and thermal treatment. Concentrations of some rare earth elements (lanthanum, cerium, samarium, europium, ytterbium, lutetium), scandium, actinides (thorium, uranium) and other trace elements (gallium, hafnium, zirconium, tantalum, arsenic, cobalt, antimony, chromium, caesium, tungsten) have been determined. Several of these elements occur in concentrations distinctly higher than their average content in clay rocks. The mechanism of concentration of these elements is connected with such accessory and/or secondary minerals as crandallite, zircon, rutile and anatase. (author)

No abstract available

[en] Some rare earth elements, actinides, alkali metals and other elements were determined in a kaolin sample and its size fractions using INAA. The most important mechanisms of the elemental concentrations in different size fractions were identified as sorption and diadochic substitution. (author)

[en] Instrumental neutron activation analysis has been used in the determination of the presence of actinides (Th and U) in a number of 'raw' and 'washed' kaolins and in different size fractions separated from some of them. The results of analyses obtained are discussed and interpreted. Diadochic substitutions of actinides in the structures of some accessory (zircon) and secondary (crandallite) minerals were found to be important mechanisms for their concentration. (author). 9 refs, 4 figs, 3 tabs

[en] Two series of standards for quantitative EPR measurements of isolated and interacting Mn²⁺ ions were obtained. The standards were applied for determination of the level of manganese impurities in sphalerites and illite clays. They were also used to check the effectiveness of doping of montmorillonites with Mn²⁺ ions, which may create active centers for adsorption and catalysis. (author)