On-line nuclear techniques in the coal industry

Developments and applications of on-line nuclear gauges in the coal industry are reviewed. The growth of this industry over the past decade has been accompanied by a rapid increase in the application of nuclear on-line analysis gauges, particularly for the measurement of ash and slurry content, and elemental composition. Over 250 on-line ash gauges have been installed worldwide since about 1980, of which about 165 are dual-energy γ-ray transmission gauges. The use of on-line microwave and capacitance moisture gauges, which are operated in combination with nuclear gauges, has also increased rapidly over this period. During the past few years 26 prompt γ-ray neutron activation analysis gauges have been sold or installed in the North American coal industry, mainly for the analysis of suphur.