Determination of the ash content of coal samples by nuclear techniques with bismuth germanate detectors
Chompon Khoonthiwong, Phannee Saengkaew, Nares Chankow
Abstract
A new promising nuclear technique to determine the coal-ash content was investigated using a bismuth germinate (BGO) detector instead of a sodium iodide-thallium [NaI(Tl)] detector for the dual-energy gamma-ray transmission (DEGT) measurements at 59.6 and 661.7 keV. The peak detection efficiency of the high-energy gamma-ray radiation was about two- to three-fold higher when using a BGO than a NaI(Tl) detector. This would increase the potential operation safety by allowing the use of a lower radioactivity level or a shorter measurement time. To analyze the coal-ash content using DEGT, the relationship between the transmittance ratios and the coal-ash content was successfully achieved as a linear equation, while the coal-ash contents determined by DEGT were in a very good agreement with those determined by X-ray fluorescence spectroscopy and standard chemical ASTM3174 methods, showing a highly linear relationship. In brief, the DEGT at 59.6 and 661.7 keV using a BGO detector could be developed to be a new promising approach to determine the coal-ash content as a real-time and on-belt analysis or a portable device in further investigation.