Image analysis-based approach for evaluation of velocity of detonation and post-detonation fumes from blasting events of modified ANFO explosives

The efficacy of the commercial explosives for effective rock breakage is a function of their detonation behaviour. Toxic post detonation fumes are environmental hazard and known to cause several health problems to the miners. Therefore, it is important to evaluate the detonation fumes while using explosives for rock blasting. The existing methods for the assessment of detonation behaviour and detonation fumes are cost intensive and time consuming. So an image analysis based technique has been proposed in this study to evaluate the detonation properties and fumes of the explosives. The experimental trials for this purpose was conducted at the laboratory. To ensure the variations in the blasting outcomes, the ANFO explosive samples were prepared with the blending of diesel oil with used lubricant oil. With the increment in the blending ratios, the detonation behaviour of the explosive mixture deteriorated, and thereby the velocity of detonation decreased. The fumes analysis of the prepared explosives was carried out in a confined explosion gallery. The blasting fumes for open blasting was captured using videography. The video-graphic images at different time delays were segregated. The grayscale scores and RGB scores of these images were extracted. The extracted scores were compared with the detonation velocity and fumes. The analysis shows that there is a strong correlation among the grayscale score and blasting outcomes viz. detonation velocity, density, CO, NO and NO2. The similar method with large dataset may be used in future for devising a cost effective image based algorithm to predict the blasting outcomes.