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Blasting engineers learning their trade at Colorado School of Mines

29th April 2019


Computer modelling has greatly improved the blasting process Computer modelling has greatly improved the blasting process
Blasting with a wired system could become a thing of the past Blasting with a wired system could become a thing of the past

The pace of technological change means that education is more important than ever. Colorado School of Mines, located in the foothills of the Rocky Mountains, has nearly 6,000 students and a diverse range of research interests, including materials and additive manufacturing as well as its core mining activities.

Jamal Rostami, associate professor, Timothy J. Haddon/Alacer Gold Chair in Mining Engineering and director of the Excavation Engineering and Earth Mechanics Institute (EMI), states that, “Drills are becoming more intelligent and in addition to self-diagnostic systems on many of the new sensors installed on the units, they can optimise the drilling operation by controlling the thrust, torque and feed rate of the drill bit. Many of the surface drilling units are now equipped with GPS and can locate the drilling spot and know how deep they have to drill.

“The underground units work in tandem with total stations from surveying systems or laser guidance and can position the holes in the desired pattern which is communicated to them via wireless system or by simply plugging a jump drive. There are drills on the market that can assess rock strength and jointing in the rock and develop a 3D map of the area to be blasted so that the charge in each hole can be customised for optimised results.”

When asked about the future, Rostami says, “There is always interest in improving the drill units and their efficiency. One of the issues of acute interest for drilling is to mitigate the noise from the operation that caused hearing losses. This is through new materials and damping systems in the drill unit and drill string so that it can pass the energy to the bit but reduce the noise. Hard facing of the bit and drill rods to slow down the wear process is of interest and the use of PDC or synthetic diamond for bit and interfacing the rock is becoming very common and affordable.”

Blast off

The relentless advance of computing power is having an inevitable effect on how blasting is planned. Rostami notes that, “The modelling of the blast process has been evolving through the years and we can estimate the size distribution of the material in the blast heap, project the movement of the materials and allow for optimisation of blast sequence so as to prevent flying rock and air blast, while directing the material to shape a heap that is easier to load and carry.”

Sridhar Seetharaman, associate vice president of Research and professor of Metallurgical and Materials Engineering adds, “In the next 10 years we will see more micro-structurally aware models and machine learning. There will be a growth in cheaper explosives, with a move to mixing on the spot rather than storage, an important safety consideration. Also safety-related, there will be increasing efforts to reduce fly rock, a tightening of procedures and better control of the shape of the shock wave with advanced manufacturing controlling the structure and initiation points.”

With the wider environment in mind, he reckons higher quality AN-based formulations will become more important because they create less harmful smoke.
As well as the materials, Seetharaman sees change in other areas. “Detonators will become more elaborate, with increased reliance on codes or fingerprints. Also, vibration analysis will be part of how blasts are designed.”

The bigger picture

In the planning stages, technology is no less crucial. Jürgen Brune, professor of Practice and Associate Head of the Mining Engineering Department observes, “Robotic and automated LiDAR surveys are already widely used in surface mines. Technologies for simultaneous locating and mapping (SLAM) are improving and we are seeing robots and drones move autonomously in GPD-denied underground mine environments. Also automation and autonomous operation will become increasingly dominant in mining as well as in public and private transportation.”

A discussion with an academic about technology would be incomplete without a word on what it’s doing to the actual business of teaching. Brune says: “Digital technologies, big data analytics, automation and autonomous operation will have a major impact on the industry. Virtual and augmented reality will improve the ability to perceive safety and health hazards as well as production data. Digital tracking of miners and equipment improves safety and productivity. Increasing degrees of automation remove miners from hazardous environments. Our mining engineering curriculum is currently undergoing revision to include these digital technologies.”

As a final thought on the industry in general, Brune concludes, “Mining continues being necessary and vital to humanity. The demand for mined goods increases with the rate of population growth. Although there is some recycling of precious metals, very little concrete, for example, is recycled. For many commodities, recycling remains more expensive than mining and processing.”

“Battery technologies will continue to evolve, potentially generating considerable demands in minerals other than lithium and cobalt. This is an important area to watch. Key areas for improvement are energy density and time to charge. Also, battery safety will become an area to be watched.”

Other side of the pond

Meanwhile, in the UK, the Camborne School of Mines (CSM) has been a part of the University of Exeter in South West England since 1993. In 2004 it moved from the Camborne area to its current location at Penryn. It’s a newly built university, where much of the teaching involves the use of software that varies from simulation work though to mine design and visualisation. Field trips and direct exposure to the industry are also important parts of the student experience.

Dr Andrew Wetherelt is programme director and senior lecturer for BEng/MEng Mining Engineering. Of the survey process, he observes, “3D remote surveying using scanners and drones has really advanced in the past few years. It has become the norm now to develop
large point clouds or photogrammetric analysis of a mining project. I possibly see the development of a full 3D and visualisation headset with capacity to measure and locate ‘on the fly’.” Vibration analysis is one of Wetherelt’s areas of research. “Unfortunately we are still using a 2D PPV against a Scaled Distance approach. This could quite easily be developed into a 3D approach where PPV against distance against charge mass is drawn up, thus enabling greater precision in prediction.”

When considering the impact of modelling, he believes it has the capacity to enable blast design engineers to forge complex timing lace-ups without creating superimposition, particularly with the use of programmable electronic detonators (PEDs), offering a greater link up with the impedance of the rock and product development, which should ultimately develop more scientific blast designs.

Wetherelt continues, “Clearly one of the main changes that has come about in the past has been PEDs, the use of which has become game-changing. There are already trials being undertaken whereby remote blasting of fully loaded holes without a wired system can be done. This may well be revolutionary for underground mining, even challenging the classic stope designs we all know and accept.”

Where explosives are concerned, he adds: “Remote loading of explosives using a robotic system is on the horizon. Whether the human element will ever be removed is doubtful at the moment, but this will trigger changes in the legislation. The use of bulk explosives in mining has already made things inherently safe. I anticipate explosives that can be developed whereupon less noxious gases are generated. This will be particularly important where re-entry times can be reduced in underground tunnelling. The introduction of RFID tags for mis-fire identification could be developed.”

As a final comment, Wetherelt reflects on the mixed fortunes of the industry. “Student recruitment into the only undergraduate mining programme in the UK remains challenging. A number of generous year 1 entry bursaries are available at the Camborne School of Mines, however getting today’s secondary school students to apply to do mining engineering at undergraduate level is difficult. Notwithstanding this, our postgraduate numbers are very buoyant.”







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