Mesa Verde Enterprises, based in Alamogordo, N.M., owns and operates a 160-acre quarry and is the largest asphalt supplier in Otero County. It operates a pair of ready-mix plants, a construction and demolition debris landfill, and a construction business. MVE has more than 150 employees.

The company recently installed a Cemco V-Twin 160 Turbo vertical-shaft impactor. This was in answer to increased demand. Over the last five years, demand for aggregate in the Alamogordo area has grown to such a degree that an upgrade on the main crushing operation became priority one, says Jeff Rabon, the firm's operations manager.

“A combination of factors, including a steady influx of retirees, has resulted in a huge upturn in development,” Rabon says. “One of the components which was sorely in need of an upgrade was our VSI. An older unit, it was starting to suffer downtime issues and cause something of a bottleneck for us. We have very little natural sand occurring in this area, so manufactured sand — used in support of our concrete and asphalt operations — is one of our key products. A VSI produces a cubical particle, much better suited for manufactured sand than the elongated particle common to cones.” Rabon says the new VSI has increased production by 30%.

MVE's material is pulled from the pit floor, fed into a hopper and run past a rock kicker that removes material larger than 6 inches in diameter. Custom-built 100-foot Excel over land conveyors take the material up to the crushing plant where it is first fed into a Terex Cedarapids 20-× 6- × 3-foot triple-deck screen.

“We have a capability of creating better than 40 different products which allows us to supply material both for our own companies and for others in the area,” Rabon says. “So aggregate sizes out of that screen can be modified to meet our demand. Material headed off the screen and into the VSI will be anywhere from ½ inch to 6 inch going in and, generally, a 1-inch minus base course coming out. That product is then taken by loader and fed into the wash plant.”

MVE's wash operation includes a Cedarapids 6-× 16-foot wet plant that sits atop an Eagle 36-inch double screw. That plant works with a second wash plant.

“If material from our pit has one shortcoming, it's that it has a high clay content,” Rabon says. “Material exiting the first wash plant is still too dirty, so we do a secondary wash through a Kolberg-Pioneer with a 36-inch sand screw, which gets the product clean enough to meet the ASTM C-33 specs.”

Despite having to deal with additional bottlenecks in the conveyor facet of the operation, MVE has seen throughputs increase to more than 450 tons per hour. After those issues are resolved, Rabon hopes to see rates around 650 tons per hour. The VSI is rated for 900 to 1,000 tons per hour. MVE will generate between 400,000 and 500,000 tons of product this year. That includes base course, structural fill, sand and other aggregate products.