Minnesota plant design reducing material handling

Says Kraemer Mining & Materials’ Cody Ladd: “When you put in the effort to build off a plan of not rehandling material, it’s really pervasive.” Photo: P&Q Staff

The more material is touched, the more costs an aggregate operation incurs.

The best quarry operators understand this concept well, but minimizing the number of touchpoints in and around a plant isn’t necessarily an easy thing to do.

Kraemer Mining & Materials, however, aimed high several years back when it reconfigured the plant at its operation in Burnsville, Minnesota. The company sought to limit the number of times material is touched at its Burnsville Quarry, and its owners spared no expense when updating the processing equipment there in 2017.

“What you have here is a philosophy of limiting material handling,” says Cody Ladd, president and COO of Kraemer, who joined the company last March. “There’s a communal groan anytime you have to touch a stockpile, but we thankfully haven’t had to touch one.”

Seeking efficiencies

The plant Kraemer built in Burnsville was undoubtedly designed to mitigate material handling.

Following drilling and blasting, material is loaded into a portable Lokotrack 3749 jaw crusher that’s positioned near muckpiles. From there, material traverses 3,000 ft. of conveyor belt before hitting the first of two surge tunnels.

In recent years, Kraemer Mining & Materials’ Burnsville Quarry has produced roughly 1.75 million tons per year. Photo: P&Q Staff

“The beauty of the surge tunnels is if there were something to go wrong with any other aspect of the plant – if we had to shut down a primary, if we had to shut down our secondary – we can keep production per hour consistent,” Ladd says. “That’s fantastic for being able to do the maintenance necessary and mitigating the cost of any sort of shutdown.”

TeleStackers are also instrumental in Kraemer’s ability to limit material handling.

“Superior [Industries] came in and did a plant optimization in 2017,” Ladd says. “Everything out there is Superior for the most part. The TeleStackers are really interesting. They add about 30 percent of additional material to the stockpile space – much bigger piles.”

Still, the efficiencies Kraemer gained are better understood when considering the operational flow prior to 2017.

“We relocated from the top of the quarry up by the office,” says Mike Hoffman, plant manager at Kraemer, who started working at the operation in 1998. “The plant was up there years ago, and material was hauled up there at one point. Then, in 2004 or 2005, we put in a big overland system to convey all of the 8-in.-minus up there on a 42-in. belt.”

But even that modified setup wasn’t the most efficient, Hoffman says.

Hoffman

“It was probably close to a quarter mile or a half mile to get up there,” he says. “We would process it on top and haul all of the finished product back down to the bottom to stockpile.”

Based on today’s plant flow at Burnsville, finished material isn’t touched until it’s loaded into on-road trucks.

“Now, we’re relying on fewer moving parts and fewer diesel engines,” Hoffman says. “It’s much more efficient.”

Additionally, the revamped plant makes for a safer operation, according to Hoffman.

“Back in the day when we had the big haul trucks, you didn’t follow those up the ramp,” Hoffman says. “If the brakes went out and they had 100 tons on them and they rolled backward, you could crush a truck like that. We are absolutely safer now.”

Ladd agrees.

“If you look at the plant layout, there are very few pinch points,” he says. “That’s something I like quite a bit. There aren’t a lot of blind spots. I’ve run into that a lot on tours of quarries, where you’re coming around a pile and you’re hoping nothing is on the other side.

“The layout itself is really well thought out,” Ladd adds. “They were definitely building the plant with safety in mind.”

Other operational details

While Kraemer Mining & Materials utilizes loaders at the Burnsville Quarry, the company was able to eliminate haul trucks with its 2017 investments. As plant manager Mike Hoffman says: “Years ago when we relied on trucks, your plant was only as good as your trucks.” Photo: P&Q Staff

While Kraemer’s plant has produced 2 million tpy of material, Hoffman says its average annual output in recent years is 1.75 million tons.
“About 1.2 million of that is washed,” he says.

Among the equipment Kraemer utilizes in its wash plant are legacy KPI-JCI screens, a McLanahan sand plant and a McLanahan ultra fines recovery (UFR) system.

“The focus here has largely been on operations,” Ladd says. “We have the UFR and the TeleStackers that differentiated us from our competitors. Commercially, we may be where the industry was 10 years ago. But operationally, I honestly think we’re ahead in a couple of key areas.”

Ladd was hired to help advance Kraemer on the commercial front. From his view, the operational excellence achieved in Burnsville is something to be replicated as Kraemer pursues growth via mergers and acquisitions.

“When you put in the effort to build off a plan of not rehandling material, it’s really pervasive,” Ladd says. “It hits the whole crew. The team is proud of that. Culturally, that’s a big thing.”

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