Portable plants are key in keeping Waterloo Quarry productive and successful during tough times.

By Kerry Clines, Senior Editor

Wisconsin-based Michels Materials uses nothing but portable plants and equipment at its Waterloo Quarry.

Wisconsin-based Michels Materials, a division of Michels Corp., does things a little bit differently at its quarries. Instead of hauling material from the quarry face to the primary plant, Michels moves  the primary plant to the quarry face. The company uses nothing but portable plants and equipment in its quarries.

The benefits of being portable

The benefits of using portable equipment are very apparent at Michels’ Waterloo Quarry near Waterloo, Wis. “Every piece of equipment in this quarry is portable,” says Maurice (Moe) Bohrer, sales manager for Michels Materials. Having portable plants gives Michels flexibility, not only in terms of individual sites, but also for crushing at other quarries. The company operates more than 100 aggregate operations throughout the state and the use of portable plants allows Michels to go into a specific location on a job-by-job basis. It can move the plants into the aggregate site closest to the project and crush just the amount of material needed for the project, which allows Michels to control its inventory.

Routine maintenance, such as relining cone crushers, is performed on a frequent basis because of the abrasiveness of the quartzite material being mined.

Haul trucks are no longer used at the quarry for production, they are only used when stripping. Portable plants allow the primary to be located close to the face, eliminating the need for haul trucks. “Once we set up our overland conveyor system, we did away with using haul trucks in production,” Bohrer explains. “The land conveyor carries the material to the secondary crushers and the finishing plant. That’s a real advantage because it eliminates not only the cost of maintenance, fuel, and a haul truck driver, but it provides for more consistent feed to the plant as well.”

Using portable equipment allows Michels to centralize maintenance for all of its quarries. “During the winter months, we move the equipment to our central headquarters in Brownsville, Wis.,” Bohrer says. “This allows us to go through each piece of equipment to make sure it’s ‘up to snuff’ before it goes back out in the spring. Because of our short production season here in Wisconsin, we don’t want to have a breakdown in the field. Doing all the maintenance in one central shop allows us to make sure the equipment is the best it can be when it arrives at the quarry to begin production.”

The material

Waterloo Quarry’s deposit is quartzite, which is a very hard material that can be rough on equipment. “Quartzite is a metamorphic rock, a hard stone,” Bohrer says. “It produces a very good finished product, but it’s tough on everything it touches, from when it’s being drilled, to when it’s sold as a finished product. Due to the abrasive nature of quartzite, drill bits wear down twice as fast as they do in a limestone quarry and crusher liners wear out four to five times faster. We use a very proactive approach with our onsite QC lab to run several gradation tests each day, while each product is being produced, to not only ensure that our products are meeting their required gradations, but also to monitor the wear on our crusher liners and screens, so we know when to change them before we produce an out-of-spec material.”

The overland conveyor system carries material up to the secondary crushers and the finishing plant where it is washed and stockpiled for loadout.

Three portable plants (crushing spreads) are currently operating at the Waterloo Quarry. However, there may be as many as five plants operating in the quarry at the same time, depending on production demands. Each plant is a separate entity with its own plant manager and production schedule. A fuel tank, generator, water truck, and tool trailer are standard issue for each crushing spread. The tool trailers store everything necessary for each plant to do the job.

“We don’t typically move the plants around inside Waterloo quarry during a season,” Bohrer says. “Our faces are so big and the deposit is so deep, we just set up the plant at the beginning of the season and that’s normally where it stays throughout the remainder of the year. The next spring, we may relocate it, but we typically try to position it in such a way that we don’t have to move it within the quarry. We’re not chasing the face, because we’re usually working two sides with big benches that will give us an adequate supply of feed material.”

Waterloo Quarry produces approximately 30 different products, but the four main products are dense base aggregate for highway and road construction, railroad ballast, asphalt chips for use in asphalt production, and rip-rap/armor stone.