Blasting: An academic speaks

Paul Boughton

Jon Lawson meets an expert in blasting to discuss the future of this ‘explosive’ sector

Dr Catherine Johnson is assistant professor of Explosives Engineering at Missouri University of Science and Technology. She completed her Doctoral degree entitled Fragmentation Analysis in the Dynamic Stress Wave Collision Regions in Bench Blasting at the University of Kentucky in December of 2014.

She earned her Bachelor of Engineering and Master of Engineering in Mining and Quarry Engineering at the University of Leeds, UK in 2012. Her masters research focused on the origins of air overpressure from quarry blasting. Her current work is focused on shock physics and fragmentation prediction. These are her thoughts on the future of the industry.

IME: How will blasting in mining change over the next 10 years?

Catherine Johnson: As many blasting engineers reach retirement in the coming years, young graduates will replace them that have been brought up with computer aided design programs and a fresh take on industry. Many blasters are stuck in their ways and do not embrace change. These changes will include automation and robotics.

IME: What impact will advances in computer modelling have?

CJ: Blasting is one of the first steps in the whole mining process. Fully autonomous mining of shovels and trucks, currently in its R&D stage, will not be fully possible if the blast pattern and resultant muck pile is not also modelled.

IME: What about the explosives themselves, how will they change?

CJ: Mining explosives have not changed significantly in years. The quantity required for the relatively low cost makes drastic changes difficult to overcome for the industry. EPA regulations and fines with regard to NOx emissions etc. could change this however. Detonators and equipment will change a lot more than the explosives themselves.

IME: So what advances will we see in detonators?

CJ: Sub millisecond electronic detonators will be commercially available very soon. The major concern will always remain around the cost comparison to non-el or electric but the improvements in accuracy are significant.

IME: How can safety be improved?

CJ: The biggest problem for safety in blasting is a rock hitting the blaster. Moving them to a safe location away from the blast area is currently occurring but is limited by the use of a shot cable of non-infinite length. Having radio controlled trigger systems so that you can move miles rather than meters away will help this significantly.

IME: Will we see other changes in legislation?

CJ: Changes in legislation with regard to the environment will continue. Many efforts are being made by researchers to find realistic values for the legislation as they are currently unrealistic with no quantitative data backing up the values set.

IME: Can blasting be made more environmentally friendly?

CJ: Practices of using the correct explosives in wet/dry holes for example can improve visible side effects from blasting such as NOx and blasting on non-windy days can prevent this from travelling outside of the blast site. These are practices that have been around for decades. Blasting practices have not changed, but environmental regulations have become more stringent resulting in more mines breaching these limits.

IME: What about robots?

CJ: The use of drones for face profiling and surveying is emerging in the blasting industry. It is becoming crucial for the minimisation of flyrock incidents to monitor the exact burden in front of a hole and drones are being used for this at many sites. Quarries are now using drones to survey the land for reclamation, flat land in the USA (not on swamp land) in many areas is hard to come by. Surveying very flat land to sell after operation for large supermarkets etc. is very profitable as these quarries are usually close to populated areas.

IME: What other changes are on the horizon?

CJ: Automated drilling of blast holes is under R&D. Coupled with this should be automated drill logging. This is currently done by hand, very poorly. Automation of this will provide more accurate drill logs that can improve blasting practices by knowing accurate location of weak seams, water or heavily fractured material etc.

Pic: Caption: Dr Catherine Johnson, assistant professor of Explosives Engineering, Missouri University of Science and Technology. (sent as Catherine Johnson 015.jpg)

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