Portable ‘mega’ cone contributes to doubling plant output

Elam Construction, headquartered in Grand Junction, Colorado, is one of the largest American-owned and locally operated paving contractors and asphalt producers in western Colorado, as well as a major producer of ready-mix and other concrete products. Elam produces road base, asphalt and concrete aggregate for in-house construction and external sales.

Elam began as a family-run business in 1956. It became one of Summit Materials’ growing family of companies in 2012, specializing in aggregate, cement, ready-mix, asphalt and paving construction.

Elam owns and leases 21 high-quality sand-and-gravel sites in western Colorado and eastern Utah. Several of these are located in Grand Junction. Site sizes are based on supply and demand in the areas, running from 20 to 150 acres.

This 500-hp cone crusher feeds crushed material to a conveyor feeding the 6-ft. x 20-ft. screen plant. Photos courtesy of Elam Construction.

The company had been utilizing three generator-powered portable electric crushing systems – one large and two small – in order to produce a number of aggregate products at about 14 of its locations per year on a rotating basis, operating 10 to 11 months annually. The remaining sites would sell previously crushed aggregate to local customers and accumulate material to be crushed later by the portable systems.

The two smaller crushing systems were exactly alike, each producing at a relatively low volume (about 200,000 tpy). Yet those two systems were easy and economical to move. The much larger third portable system (about 500,000 to 600,000 tpy) was more complex, so it was more time consuming and costly to move.

The three-plant combination had worked well, but in recent years Elam was finding it harder to keep up with growing aggregate demands for its internal needs and for external sales throughout its 200-mile market radius. In 2015, the company acquired LeGrand Johnson, an aggregate producer in Moab, Utah. LeGrand Johnson was using an outdated stationary crushing plant that produced about 250,000 tpy and needed to be replaced. Elam had to increase aggregate production dramatically to meet future demands and supplant the Moab production.

“We didn’t want to add a fourth portable crushing plant,” says Greg Monger, Elam’s manager of aggregates. “What we wanted to do was replace one of the smaller plants – consisting of a 22-in. x 48-in. Cedarapids jaw, a 4-ft. x 12-ft. Masaba screen, a Cedarapids RC 54 II cone closed on a three-deck 6-ft. x 20-ft. Cedarapids screen and several conveyors – with an equally simple plant that would dramatically increase production and would be just as mobile.”

A simple solution

A wheel loader feeds 12-in.-minus bank material into a Lippmann primary jaw crusher. The jaw crushes to 3-in.-minus rock, which is conveyed to the Cedarapids screen.

Monger and his associates investigated several manufacturers’ equipment, with an eye to production efficiency, ease of portability, simple maintenance, reliability and expected service life.

“The cone crusher is especially important in our system,” Monger says. “We needed a highly mobile cone large enough for a high-volume system.”

Elam was most impressed with the 500-hp Terex Cedarapids MVP 550X, which is designed for high-force applications with its Rollercone bearing design. It easily handles sand and gravel, as well as shot rock and recycled materials.

“We had such good service from Cedarapids equipment in hard use over the years that we were confident the 550X would do everything the manufacturer claimed,” Monger says. “Further, we have a good relationship with our Cedarapids dealer, Power Equipment Co., in Denver. We perform routine maintenance and repairs in house, but we rely on the dealer for major repairs and fast delivery of parts as needed.”

A generator powers Elam’s new portable, all-electric system. The system combines a Lippmann J2450-VGF5120 primary jaw, a Cedarapids 6-ft. x 20-ft. pre-screen, a Cedarapids MVP 550X cone crusher, a Cedarapids/Fab Tec 6-ft. x 20-ft. tandem screen plant and supporting conveyors.

Left to right are Greg Monger, Elam Construction’s manager of aggregates, and Tyson Carroll, the company’s crusher foreman.

“The MVP 550X cone is indeed the heart of our new crushing plant,” Monger says. “I call it our ‘mega cone’ because it meets our volume requirements and keeps the system humming. It is the largest cone we found that is easily portable for our situation, and it meets roadway height and weight requirements.

“Most 500-hp cones are too heavy and would require additional axles or disassembly. The Cedarapids MVP 550X enables us to utilize a single cone in a high-production system that would otherwise require two cones with higher moving costs and maintenance of two machines instead of one. This new plant can produce 400,000 to 500,000 tpy, which is more than double the production of the old portable system it has replaced. We’ve been using the new system since June 2016, and all is working extremely well.”

Crusher performance

Typically when making asphalt aggregate, the system is currently producing about 200 tph, concrete aggregate at about 300 tph and road base at about 400 tph. Schedules of these three different modes are dictated by sales requirements, Monger says. Elam runs 10-hour shifts, with the crushing plant usually running eight-and-a-half hours.

These stockpiles include 1/2-in. chips (right) and 3/16-in. crusher fines from the tandem screen plant.

In a typical crushing and screening layout, 12-in.-minus bank material is fed into the jaw. The jaw sizes the bank run to 2 1/2-in. to 3-in.-minus rock, which is conveyed to the single 6-ft. x 20-ft. screen. The screen separates out 3/4-in.-minus naturals and produces sizes 3/4-in. to 3-in.-minus rock that is conveyed to the cone. The cone is closed on the tandem 6-ft. x 20-ft. screen combination and typically produces 5/8-in.-minus and 3/8-in.-minus rock and a 1/4-in.-minus crusher fine. These final products are used primarily for asphalt and concrete production. The 3/4-in. naturals normally would go to a separate washing plant for production of #67 rock and concrete sand. At some locations, the 3/4 in. naturals can be blended back into coarser road-base products.

Elam’s staff size varies during the year based on production requirements. The company had 247 employees at its peak season in 2016. In order to maintain a sustainable safety culture, each new employee must adhere to a strict training protocol based on standards of various agencies, some of which are Mine Safety & Health Administration, Occupational Safety & Health Administration, the 5S Program and Task Training (THINK Program).

Elam Construction is a community-minded company that is involved with many charitable organizations in the Grand Junction area, and the company has often donated materials for local and regional projects.

Carl Emigh of CME Creative Services Inc., Marion, Ohio, is a freelance writer and marketing communications specialist serving the aggregate, recycling and construction industries.