Aggregates Crushing And Screening Operations
A STORY OF INNOVATION, GROWTH, AND DIVERSITY
The crushing-and-screening operations at Rocky Mountain Aggregates and Asphalt are very compact and highly organized. This photo shows the company’s Kodiak K300 cone crusher and Combo screen at work in the concrete rock pit.
Rocky Mountain Materials and Asphalt operates two KPI-JCI crushing-and-screening plants. The Kodiak K400 cone crusher (top left photo) is currently working in the company’s asphalt rock pit, while the Kodiak K300 cone crusher (not shown) is working in the company’s concrete rock pit. According to Tom Smith, the company’s director of quarry operations, the K300 crusher produces about 450 tph (408 tonnes per hour), while the K400 crusher turns out almost 700 tph (635 tonnes per hour).
Both of the company’s crushing-and-screen plants use a KPI-JCI Combo screen (bottom left photo) that combine the advantages of an inclined screen and a horizontal screen. The top two decks on a Combo screen are inclined on the feed end and in the middle—but they are flat on the discharge end. The bottom deck is flat. As a result of this unique design, material travels faster in the feed section, thereby reducing the depth of material on the screen and allowing the fines to pass through the screen openings much quicker. According to Tom Smith, the Combo screen processes the material and gets it down to the third deck much quicker. “Consequently,” Smith said, “you get more use from your third deck of screens than you do with a typical flat screen.”
In 1977, Rocky Mountain Materials and Asphalt, Inc. was a small company that dealt mainly in decorative landscape rock and miscellaneous aggregate materials.
Today, 30 years later, the company is a leading producer of aggregates and paving materials on the Front Range of Colorado. Over the years, it has grown to the point where it now operates five gravel operations, two hot-mix asphalt (HMA) plants, and two concrete plants, including a new state-of-the-art premix concrete plant.
“We’re staying busy,” said Tom Smith, director of quarry operations for Rocky Mountain Materials. “We do a lot of work for the county and for the five military bases here in this area.” The company’s primary market is the Colorado Springs area. That is where Rocky Mountain Materials maintains its headquarters.
“We got into the concrete business six years ago because the demand was high in Colorado Springs,” Smith explained. “At the time, a contractor couldn’t get concrete without waiting as long as two weeks. So we bought a plant, put it up, and before we knew it, we had 40 trucks delivering concrete. We just put up our second concrete plant—the new premix plant—in July and everything is going well.”
The innovation, growth, and diversity of Rocky Mountain Materials has led to some significant equipment acquisitions in the last year, as well.
“We needed to upgrade some of our main production equipment,” Smith said. “Earlier this year, we bought a Kodiak? K300 cone crusher and a 7×20 Combo screen from KPI-JCI to use in the rock pit where we get the aggregate for our asphalt plants.” This was not Smith’s first experience with KPI-JCI crushers or Combo screens. Back in 2004, they bought a Kodiak K400 cone crusher and an 8×20 Combo screen. That set-up is now located in the company’s concrete rock pit. In that same rock pit, the company operates a KPI-JCI 7×20 wet deck with twin screws.
As far as the Combo screen is concerned, Smith said the concept is working well for them in their operations because of its unique capabilities.
“I like the Combo screen,” said Smith. “I have been in this line of work for a long time and I have always preferred flat screens. But the Combo screen has some definite advantages. It has an inclined section at the head end—and that section of the screen gets the material stratified across the deck and down to the third deck much quicker. As a result, you get to use much more of your third deck than you do with a typical flat-screen unit. On a flat-screen unit, you are really only using the last 10 ft. (3.0 m) of a 20-ft. (6.1-m) screen. But the Combo screen is built in such a way that the material gets down there to the third deck within the first 2 ft. (0.6 m) of the screen.”
Smith said their main reasons for upgrading their equipment had to do with finding ways to speed up the processing, increase the production, and reduce downtime.
“Aggregate processing is the starting point for our company’s overall concrete and asphalt operations. If we don’t produce aggregate, our concrete crews don’t work and our hot-mix asphalt crews don’t work. If we’re not productive here in the rock pits, then nobody else in the company is going to be productive, either.
“For that reason, one of the things we look for in an equipment supplier is customer support and service-after-the-sale. We had some small problems with this equipment at the beginning. It’s a fact of life: You’re going to have problems with anything you buy. But KPI-JCI reacted very quickly when we called them for assistance. And because of that quick response, they were able to keep our downtime to a minimum.
“What would I tell another producer who was looking for new equipment? Well, I’d tell them that if they want somebody who stands behind their product, there is not anyone better than KPI-JCI.”