PRIMARY INVESTIGATION OF A DESIGN FOR A DUAL-ENERGY GAMMA-RAY TRANSMISSION GAUGE TO DETERMINE THE ASH CONTENT OF COAL ON A CONVEYOR BELT

To design a dual energy gamma-ray transmission gauge for measuring, on -line. the ash content of coal, an investigation was carried out to de termine the relation between the theoretical mass absorption coefficie nt (muBAR) and the % ash of coal in the Kerman District Coal Mines (KD CM). Because coal, transported on a conveyor belt, may be a non-homoge neous mixture from one or more mines, it was decided to compare % ash in a mixture of coals from several mines with that from individual min es, the measurements being made whilst the coal was being transported on a conveyor belt. The investigation shows that the relation between the mass absorption coefficient and the % ash in a coal mixture from s everal mines cannot be used to assess, accurately, the value of muBAR for coals from individual mines in this particular region.