Uranium in mining waters of kaolin open pit in [formula omitted]arów (Lower Silesia); methodology of determination and genetic remarks

Abstract

In this paper, a method of determination of uranium 238 and 234 in mining waters of Andrzej kaolin open pit in Z ̇ arów (Lower Silesia) is presented. The method is based on independent measurements of alpha and beta radiation intensities by means of a liquid scintillation spectrometer α/ β. The initial volume of water sample was 3 dm 3, then it was diminished by chemical preparation to 6 cm 3, and then 12 cm 3 of scintillator was added. The lower limit of detection (for the measurement time of 8 h) for both 234U and 238U amounted to 0.02 Bq/dm 3. For determination of the uranium content in ferruginous sediments precipitating from mining waters of the above-mentioned open pit, gamma ray spectrometry was used. The obtained results may be viewed as a contribution to studies on anomalous uranium concentration within this kaolin deposit. The elevated uranium content, in comparison with its average concentration in the Earth crust, is characteristic for parent rocks of Andrzej kaolin deposit, which are granitoids of Strzegom–Sobótka massif. In connection with it, the high uranium content can be observed not only in kaolin and weakly kaolinised granitoids from the deposit in question, but also in mining waters genetically related with them.