Development of a novel non-contact and quick-response detector for boron in coal fly ash based on thermal neutron absorptiometry.

Coal fly ash (CFA), a by-product from coal-fired power plants, has many applications. However, there are concerns that the trace elements in CFA-based materials may contaminate groundwater. Therefore, many methods have been developed to rapidly measure these trace elements in CFA in order to management and/or screening their leachability. However, satisfactory methods to measure boron alone have not been reported. In this study, we developed an instrument for the non-contact analysis of boron in CFA samples. This simple instrument consisted of a sealed neutron source, a moderator, a proportional counter, and a signal processing device. The analysis method, based on thermal neutron absorptiometry, can rapidly measure the boron content within five minutes without pre-treatment. We applied the developed equipment to over 200 CFA samples, and excellent correlation was obtained between the proposed and traditional methods. These results indicated that the developed equipment is useful for managing and/or screening boron in CFA.