Spatial Effect Analysis of Coal and Gangue Recognition Detector Based on Natural Gamma Ray Method

The inability to identify accurately coal and gangue has been the bottleneck restricting the intellectualization of top coal caving. The difficulty of coal and gangue recognition lies on the fact that with the advance of working face, the change of coal caving space requires the relative position of the detector and coal–gangue to be synchronized. In order to overcome this problem, we proposed a new gangue recognition detector technology based on natural gamma ray method, which has advantages of low environmental impact and high universality. In this paper, the dynamic characteristics of coal release space are analyzed firstly and then the spatial effect of the detector is studied based on the radiation characteristics of gangue and the principle of detecting stereo angle. Finally, the effects of detector detection distance, detection angle and coal caving on detection efficiency and sensitivity are analyzed through experiments. The experimental results explain the proposed method and show that the sensitivity of the detector not only meets the requirements of on-site coal–gangue recognition but also achieves real-time detection.