Strategies to elevate drilling and blasting efficiences

By |  February 9, 2018

Photo: iStock.com/koer

The concept of change, particularly being open to change, was a common theme at Quarry Academy 2017, an educational seminar held in San Antonio.

Aggregate producers everywhere are undoubtedly resistant to change in some form. Many have processed materials a certain way for years, maybe decades. And they’ll tell you that their approach to material processing works effectively.

“If it ain’t broke, don’t fix it,” they’ll say.

But what if your approach to processing – the one that you regularly employ – was “broke” from the start? Odds are your approach isn’t completely “broke,” but minor improvements can surely be made to every production process.

Consider how the processes related to producing construction materials at your operation were instilled in your mind and validated over the years. Often, the rationale for doing something a certain way is because “this is how we’ve always done things around here.” Or, maybe an old-timer taught you a certain way, and you’ve methodically been following that person’s lead ever since.

Neither rationale necessarily means you’re right. Or, that you’re processing material in the most efficient manner possible. So maybe it’s time for a change.

“At the scale house, it’s ‘X’ dollars per ton,” says Jeff Heinemann, vice president at Sandvik Mining & Rock Technology, whose company developed Quarry Academy in conjunction with Dyno Nobel. “It doesn’t matter how you get there.

“All that really matters is what that cost is at the scale house,” Heinemann adds.

Creating change

Fortunately, aggregate producers aren’t limited to making improvements at the crush stage alone. They can institute process improvements up and down their value chain.

While a number of operators will zero in on crushing as the step that really nets them profits, the activities before and after sometimes provide benefits that are overlooked. Two areas referenced at Quarry Academy where aggregate producers could elevate their dollars per ton are drilling and blasting.

“You could be looking at hours, if not days, to process rock if you don’t [drill and blast] right,” says Scott Giltner, senior project engineer at DynoConsult, a division of Dyno Nobel.

Still, instituting change, even when a need blatantly stares you in the face, is easier said than done.

“The challenge for everybody is that things have been done the same way for so long,” says Bill Hissem, senior mining engineer at Sandvik Mining & Rock Technology in North America. “But improvement means change. Change means habits need to shift. That’s the challenge.”

Drill and blast enhancements

Contract drilling is attractive for producers who want to intensify their focus elsewhere. Photo courtesy of Dennison Creative

At Quarry Academy, Hissem referred to drilling and blasting as “chemical crushing,” a concept that is overlooked at aggregate sites across the nation.

“Quarry people love their trucks but not so much their drilling and blasting,” Hissem says.

Larry Mirabelli, senior manager of explosives and blasting technologies at Buckley Powder Co., a joint-venture company of Dyno Nobel, agrees.

“Things changed 15 years ago,” Mirabelli says. “Technologies changed. It’s why Bill and I can think of this as ‘chemical crushing.’ There are valuable tools to look at drill and blast as chemical crushing.”

Among the advanced tools available to aggregate producers are models that provide data on blast fragmentation, blast vibration and plant process optimization.
“What those models bring to us is the opportunity to evaluate hundreds of scenarios for how we can change our blast designs without going on the bench itself,” Mirabelli says. “We never had that opportunity before.”

Although a blast obviously provides the largest reduction in size to rock particles, producers can be blind to this notion. An effective blast, however, puts the primary crusher in a position to process materials with less effort.

Still, an effective blast starts with a drill job done well. These days, effective drilling can be achieved through 3-D GPS automation that improves hole location precision, minimizes over drilling on hole depth and provides for documentation of as-drilled hole locations.

Other sources of smart-drill functionality available are feed alignment systems and drill control systems. While feed alignment systems improve hole accuracy and reduce setup cycle time, drill control systems minimize system power requirements, minimize fuel consumption and optimize drill control pressures in real time.

“We’re hoping we will expand the chemical crushing aspect just because of the amount of precision and amount of data available,” Mirabelli says.

The chemical crusher, which Mirabelli and Hissem refer to as “the new normal,” controls and influences rock particle size distribution. But old drilling and blasting principles apply to this new approach, they say.

After all, detonated explosives release the chemical energy stored with them. And all of that energy goes into breaking and fragmenting rock, moving and heaving rock; into ground vibration; and into air overpressure and heat.

And in a correctly designed blast, accurately placed drill holes will put the right quantity of explosive energy in the right place.

“There’s plenty of opportunity coming to us,” Mirabelli says. “There’s excitement in the automation in drilling technology.


Measuring your operation against others

From mine planning to loadout, no two operations approach production exactly the same.

Variances always exist across sites, whether it’s the geology of the mine or the way an operation goes about processing rock. And the same logic applies to how aggregate producers approach drilling and blasting.

At Quarry Academy 2017, an educational seminar for producers and others, hosts Dyno Nobel and Sandvik Mining & Rock Technology polled attendees about aspects of their business. Attendee responses to the companies’ drilling and blasting questions are presented below. According to the companies, about 60 Quarry Academy attendees responded to each of the following questions.

Drilling

Who does the drilling on your site?
We contract drill: 60%
We own and operate our own drills: 40%

What would you like to do in the future?
We want to continue what we’re doing: 71%
We want to change to contract drilling: 5%
We want to change to do our own drilling: 25%

Blasting

The muck pile fragmentation management at my operation is:
Excellent: 2%
Satisfactory: 26%
Could be better: 60%
We take what we get: 9%
I don’t know: 3%

The biggest fragmentation issue at our operation/company is:
Fines: 18%
Oversize: 50%
Inconsistency: 28%
No issues, everything is fine: 3%
I don’t know: 1%

Kevin Yanik

About the Author:

Kevin Yanik is the editor-in-chief of Pit & Quarry magazine. Yanik can be reached at 216-706-3724 or kyanik@northcoastmedia.net.

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