PROFILE
What are the challenges in bringing these innovations into the industry? Continuous professional development. The majority of people in the sector completed their blasting tickets 30 years ago, myself included.
The problem is how do you take people forward with learning? You can use the renewal of your driver’ s licence as an analogy. Is it enough to go for an eye test every five years, or do people need to retake their driver’ s licences to ensure that they can still drive safely? It is a debate worth having.
The sector had two incidents recently that could have resulted in fatalities. The safety inspector used the right word when summarising the learning from the incident: complacency. The individuals concerned were so used to a blast happening in a certain way that they didn’ t recognise the changes that occurred as posing a potential risk. Re-education is the challenge— it’ s the issue of:“ I know how to drive, why should I be reassessed for my licence again?”
Over a short period, rock science and new technology have changed rapidly. When I joined the industry, safety fuses had just entered the market. My first miner still used boxes of detonators and a roll of fuse. He would cap length the fuse he wanted and crimp it on. I will never forget: I used a tool and he told me,“ No, that’ s not the way to do it”. He picked up the detonator with the fuse, put it in his mouth and crimped it like that. That’ s where we came from, and now we’ re using detonators that are effectively computers.
What’ s next? Well, we’ re entering a world where we’ re getting rid of the wires. As the drive towards safer operations continues, the industry is starting to use remote controlled drill rigs. With satellite technology, a drill can now position itself. The intention is to remove people from the mine face completely in an attempt to reduce blasting incidents.
So now, the drill rig can drive on the bench by its own and position itself, and it’ s complete autonomous mining. But then the explosive truck comes and someone has to put a detonator down the hole, wire it and pump it with explosives, in the dangerous area. It defeats the purpose of removing drill operators from the face. Our R & D team is actively looking at wireless and remotecontrolled delivery of explosives.
The challenge is finding partners who are interested in working with us to test such technologies. There needs to be a pull from the industry and we are joining in on those discussions. For example, we could develop hybrid machines that combine the drill rig and explosive equipment, using a boom to simply switch it around. But for that to happen, we need to work closely with drilling companies.
Is such equipment available? We are currently partnering with the University of Pretoria. The intention is to use virtual reality to model the equipment before you build it. In the past, you would build a machine and test it in the field, which is pricy. Today, you can test the pros and cons in virtual reality down to the finest detail. If the results are fascinating, you can then commit to building it in the field. To me that’ s the exciting part of where the sector is heading. I put on a pair of goggles, stand in a safe area and model the quarry as if in real life.
What will be the next wave, after wireless blasting? The use of non-explosives will eventually begin to make inroads, especially in the quarry sector that is highly sensitive to built-up areas. Traditionally, you would’ ve blasted four rows with 18 holes, but with non-explosives, you create a single line of holes along the free face and use nonexplosive tunnel cartridges, working on the principle of gas expansion, to simply crack the rock off. It sounds simple but then nature delivers the challenges of geology and the ever changing rock properties.
Quarries have been laid out specifically for blasting and the use of non-explosive blasting methods will change this, so it will be challenging.
How will the design of the pit change to accommodate non-explosive methods? You would have to design longer faces to get the same quantity of stone and you would work on much smaller bench heights. So where we typically have a 15m bench now, it will be reduced to a 3m bench. The geology also dictates the process. If you have heavily fractured ground, then the gas doesn’ t work as well and you need to line the holes to ensure that the gas can do the work.
Have you tried it out in the field? Currently, we are breaking boulders where it is blocking an ore passage or tips at underground and surface mines. Traditionally, if a boulder blocks a passage, you would bring a rig in, drill a hole and then blast it, but the problem with that is
Drone flight
you could damage the mine. With the nonexplosive cartridge method, you still drill a hole, but because there is a lot less energy, you crack it. We have done this at crushers in quarries as well.
Are there any environmental issues around these methods? No, it is all naturally occurring elements.
What is your overall outlook for the industry for 2017? I think the 2017 outlook is positive. It is about getting the building programmes going. The industry is over-subscribed and there are too many players, but that will change if we get some of these infrastructure projects off the ground.
I think it has to be a combined approach from the private and the public sector, and that would also be one of the challenges, trying to get the players to talk to each other.
And then, getting the youth involved in the quarry sector is critical. They are the ones that will determine whether the sector is going to be explosive-driven or whether we are going to find different ways of quarrying.
For me, in the foreseeable future, explosives will remain the status quo, mainly from an economic point of view, but into the future— because of environmental and urbanisation constraints— we are going to have to seriously change the way we blast.
“ The intention is to remove people from the mine face completely in an attempt to reduce blasting incidents.”
QUARRY SA | JANUARY 2017 _ 33