Solving quarry quandaries

By |  May 30, 2017
After purchasing tracked IRock equipment, it only takes Magruder Limestone a day to move its chassis-mounted equipment to another quarry. Photos courtesy of Ironclad Marketing

After purchasing tracked IRock equipment, it only takes
Magruder Limestone a day to move its chassis-mounted
equipment to another quarry.
Photos courtesy of Ironclad Marketing

Moving a few hundred feet, or even a few miles, doesn’t sound like much of a challenge. But when the move involves shifting processing equipment that far, the process can be weeks long and cost tens of thousands of dollars in labor and other expenses.

That’s the situation Magruder Limestone Inc., of Troy, Missouri, faced every couple of months as it packed up crushers and screeners to move to another quarry.

The family-owned business started in 1969, and it knows the aggregate industry from the inside out. Warren Magruder started with just one quarry. By the 1990s, he was producing more than 1 million tpy.

Now Magruder Cos., which includes Magruder Limestone Inc. and is run by Warren’s son, Mark, employs more than 75 people across eight Missouri quarries, from the Iowa border to Lake of the Ozarks.

Just as the company changed with the times, Magruder’s production manager, Clark Bollinger, knew the company’s technology should, too.

“The company started with just limestone, but it’s evolved a lot in the past three-and-a-half to four years,” Bollinger says. “We saw a lot more opportunities to expand our business in aggregates.”

The plan

Missouri’s diverse geologic composition gives Magruder Cos., which also has paving and asphalt divisions, nearly every possible aggregate type in the United States, from dolomitic rock to granite. Bollinger knew that growing the business was one avenue to profit for the limestone company, but seeking greater efficiencies would be a key part in the business development plan.

To grow the business, Bollinger and the Magruder team began using aggregate more in the asphalt market, as well as for residential and commercial construction and ready-mix. To achieve greater efficiencies, Bollinger began to seek out mobile crushers and screeners that he could quickly move across a quarry or to another quarry in the state.

“Three of our quarries are near one another in central Missouri,” Bollinger says. “We thought it would be perfect to purchase two crushers and two screeners that would travel from quarry to quarry, as needed.”

Bollinger devised the plan to save money by not purchasing more equipment than could be kept operational at once. By allowing the quarries to build up material, his team could keep the crushers and screeners operational longer.

Getting somewhere

Photo courtesy of Ironclad Marketing

Three of Magruder Limestone’s quarries are near one another
in central Missouri, which led to the idea of purchasing two
IRock crushers and two IRock screeners that would travel
from quarry to quarry, as needed.

Finding portable crushers and screeners that suited their operation and standards wasn’t as easy as Bollinger anticipated, though. His team demoed a variety of well-known crusher brands with no success – until it met G. D. Wisner, aggregate equipment sales manager at The Victor L. Phillips Co., a construction and aggregate equipment dealership in Kansas City, Missouri.

Wisner suggested Bollinger take a look at IRock Crushers’ TC-20 track impact crusher. The remote-controlled machine’s 15-cu.-yd. hopper, coupled with a 16-ft. x 52-in. vibrating grizzly feeder inlet, meant the machine could be easily fed with three bucket loads from Magruder’s Cat 980G and 980K loaders.

Wisner explained how the machine would produce uniform, cubical product, send it down a hydraulically controlled, 4-ft.-wide conveyor and deposit it at heights up to nearly 11 ft.

“We knew Clark was looking for efficient equipment that was easy to transport. That’s why we suggested IRock,” Wisner says. “Their hydraulic conveyors are easy to prepare for transport, and their two-speed tracking makes it easy to move around the quarry.”

Wisner also recommended the TS-522 TD standard track screening plant, which features four hydraulic, folding, side conveyors. It fits well in a circuit with the crusher to process as much as 670 tph.

Although the machines’ robust design and easy portability impressed Bollinger, he wasn’t ready to commit just yet. Magruder wanted the machines, but the purchases were contingent on some significant changes the company wanted done.

“They did everything we asked and it all exceeded our expectations,” Bollinger says.

One change Magruder requested was a larger hood on the TC-20 track impact crusher. Bollinger requested the change to increase productivity.
Now, Magruder’s crusher has the room to take on larger rock without the chance of the material being hung up within the walls of the hood.

Other considerations

Safety was also a factor when talking redesign. With all of the moving parts and material being crushed in the Magruder quarries, there would inevitably be some material kicked out of the machine. During the redesign, IRock added components to accommodate Magruder’s applications.

“We added heavy belting and rows of chains to the inlet chute to increase safety,” says Sean Donaghy, national sales manager at IRock. “This keeps materials from leaving the crusher.”

Also, a reversible transfer belt was added to the screening plant. The triple-deck screening plant’s original design used the belt to transfer oversized material to the oversized stacking belt. Magruder, however, did not always want to bring material to that particular stacking belt. Magruder wanted to mix it with midsized material.

“They wanted the ability to choose their mix of materials, and the changes were fairly simple,” Donaghy says. “When you run this belt one way, oversized material goes to the oversized stacking belt. When you reverse the belt, you begin to mix your materials.”

After renting the machines for several months, Magruder purchased two crushers and two screeners in early 2015.

“We can run more efficiently now and costs per ton have gone down,” Bollinger says. “It leverages our position well.”

Savings and benefits

While Magruder is experiencing benefits in terms of product consistency and quality, the company’s greatest savings is in time. It previously took 18 to 21 days to move chassis-mounted equipment to another quarry. Now, with the tracked equipment, a move takes a day.

That alone saves the company between $30,000 and $40,000 per move, Bollinger says. With a move every other month for each of the two circuits, that’s an annual savings close to $500,000.

The track-mounted equipment can also more easily be moved out. Magruder can detonate a new area of the quarry and then maneuver the equipment back in – all in about a half hour.

Before, the Magruder team needed to use tractor-trailers and remove the cribs, get them off the axles, move them out of the blast zone, detonate the new area, and piece the machines back together. The time added up. Now, the team uses hydraulic systems to fold the machines up and get moving in less than 20 minutes.

“That is a huge savings,” Bollinger says.

Magruder is also saving on labor costs. Its chassis-mounted equipment required six to seven operators while the new setup requires only two, slashing operator employment expenses by about 70 percent.

“We are seeing savings from the machines’ maneuverability and labor costs, but we didn’t think we would save on maintenance, as well,” Bollinger says. “Other than regular wear and tear, we haven’t had any maintenance issues. We are experiencing savings across the board.”

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