Coal ash parameters by natural radioactivity and neutron activation

Natural radioactivity of 400 coal and sedimentary rock samples, collected from cores of the wells drilled in the Upper Silesia Coal Basin, has been measured in order to determine the uranium, thorium and potassium concentrations with the use of a scintillation gamma-ray spectrometric system. The determined concentrations were used to identify the lithology of the rocks and evaluate the following hard coal parameters: ash content, calorific value and carbon content. The mean standard deviation of 1.3 wt% for the ash content between 2-35 wt%, 1.3 MJ/kg for the calorific value between 17-32 MJ/kg and 2.5 wt% for the carbon content between 43-72 wt% were obtained. Feasibility of determination of the ash content and the ash fusion temperature via the neutron activation technique has been examined, both in the laboratory and field conditions. The technique is based on recording induced gamma- ray intensities in two energy intervals with the help of a scintillating gamma ray spectrometer. In laboratory and in well logging, the mean standard deviations were 1.5 wt% and 35 deg. C, and 3 wt% and 45 deg. C, respectively. (author). 11 refs, 6 figs, 5 tabs