When it comes to mining engineering, Drill and Blast is one of the most technical and exciting roles available for up and coming Mining Engineers. At many operations it’s a high paced, high work load, thankless role. Some love it, some hate it. But for those who love it, they really love it – many have made a career of blowing things up and decided to never move on to other roles. Why would you?!
There is an indescribable adrenaline rush you get from pushing the initiator button for the first time and watching your first blast go off. It never gets old; every blast is unique; every blast is special.
The match that lit my flame didn’t start there. It started many years earlier when I first began my mining engineering degree. I was an undergraduate who was lucky enough to be able to find a job working alongside the blast crews. For those who haven’t worked on a blast crew, I cannot recommend this experience enough! Approach it with open eyes; you can learn about blasting in a week than you can by sitting in an office environment drawing lines on a screen or doing data entry.
So why is this of any benefit? After doing it for a while, you start to notice the minor differences in how different shotfirers operate. Better yet, you get to see what is good, what is bad and what is best practice. And by understanding the blast loading process, you become a part of the team. You can walk onto a blast pattern with the ability to talk to the shotfirer or blast crew in a language they can understand. You can stand back and observe what they are doing and point out the odd error in loading practices or tie-up. Or you can show your human side and step back into the team and help when times are tough, and deadlines are tight. If you do this, you will earn their respect forever! And by earning their respect, they will open up to you, point out mistakes in your work, share ideas, ask questions. In working together, they will inevitable make you a better engineer, and you will also make them better shotfirers. This is the dream working arrangement.
What else do you learn? I learnt that sometimes engineers don’t make the lives of the blast crew very easy. For example: I remember being covered in emulsion, loading holes in the 50 degree heat, watching the rubber of my boots start to melt on the bench being loaded. There was a cluster of holes in the distance which our MMU truck couldn’t manoeuvre around to load using its swing auger. So, I was quickly and harshly introduced to the concept of hose handling using a 2.5 inch hose. For those who haven’t done this - Try to keep it that way! But why couldn’t we get to the holes? The engineer who designed the blast pattern hadn’t surveyed the crest bund after drill bench preparation was completed and had unnecessarily angled holes from the face row back into the second row. This was a massive inconvenience as it required us to bag the collar of every hole on the route, then one by one attempt to recover those same holes after the loading had been completed. So not only did it result in uneven face burdens and inconsistent loading on the face row, it significantly slowed down the operational loading of the pattern.
But why would you want to make their lives easy? They are a process just like every other process on the mine site. You want them to be performing their task as quick as they can to reduce their $/BCM unit rate as well as turn the bench over for the next process.
As an Engineer, how can you help increase blast crew productivity?
In making changes to design, remember you are still delivering a product to the next process, so it is important to ensure you maintain blast quality so not to remove value from the overall operation. So taking this into consideration, the best means of increasing blast crew production rate can vary from site to site. As a general rule of thumb, the best productivity improvements will come from:
- maximising ANFO loading where you can,
- increasing the size of your patterns,
- keeping your drill patterns and initiation plans simple,
- and being consistent with your load plans.
- If you don’t have a dedicated dip crew, it helps to schedule smaller, MMU intensive blasts (i.e. presplit, coal shots, emulsion blasts) in between production blasts to allow the blast crew to dip the next production blast ahead of time.
So, in other words, simplify your design and scale it up. Unless it needs to be technical, don’t make it be - be boring instead. Additional to this, think of yourself as a support service –if they need something that will make their lives easier or more productive, help make it happen!
Operationally, how can you help increase blast crew productivity?
Operationally, the trucks need to keep cycling and as quick as possible. This means:
- Measure holes prior to the blast crew arriving.
- Get data to the engineers ahead of time so you aren’t waiting for them to create a load plan.
- If loading practices allow, prime holes ahead of MMU arriving.
- Dewater holes ahead of time.
- Ensuring the MMUs aren’t bottlenecking on the pattern.
- Stagger Shotfirer start times, so MMUs aren’t waiting on HE/IE from magazine.
- Stagger MMU and assistant shotfirer crib times.
- Manage your HE/IE and AN/EP supply and deliveries.
- Ensure correct storage and stock rotation of AN so the product quality doesn’t degrade.
- Review reload layout - are AN / EP / Sensitising Agents / Water bottlenecking the MMUs.
- If you can, reduce the travel distance from reload to bench. Or on-bench reload.
- During blasting, get other departments to assist as blast sentry’s so you can continue to load.
- Increase utilisation. Go to Night shift loading.
To summarise, keep those trucks running! They are your key value driver in the drill and blast process. Everything that is done around them is acting as their support network. Your job is to make sure the operation is as safe and productive as it possibly could be.