An efficient method for recognition of coal/gangue with thermal imaging technique

The identification of coal/gangue plays an important role in improving resource utilization and reducing environmental pollution. Since surface character of coal and gangue is closed to each other, it is difficult to obtain satisfactory recognition results by traditional visible image analysis methods. Therefore, a thermal image recognition method with water intervention was proposed to improve the efficiency of coal/gangue recognition significantly. In this study, surface thermal images with significant differences were generated by mixing coal/gangue with water for thermal conduction, which were recorded by the infrared thermal imager. The results show that when the water temperature is greater than the ambient temperature, the thermal images distinction of coal and gangue increases gradually with the medium temperature rose, and the thermal image with high contrast can be obtained with air motion intervention. Further comparative study revealed that coal and gangue can obtain the optimal contrast image when the water temperature is 55℃ for 15s with air motion intervention, which might be a novel way to increase the efficiency of coal and gangue identification in coal mines.