A new Lokotrack ST2.8 mobile scalping screen from Metso Minerals is helping a technologically advanced cement plant to produce a clean additive for its production process, resulting in significant cost savings. GCC America requires a very clean 1- x 4-inch limestone product for the cement additive at its large Rio Grande plant in Colorado which has its own limestone quarry on site. To efficiently and economically do this, the company consulted with the local Metso dealer, Wagner Equipment, and arranged a demonstration of the new Lokotrack ST2.8 mobile scalping screen at the plant. The operators moved the ST2.8 into the plant’s quarry and fed it 8-inch minus blasted material to make the required 4-inch clean end-product.
Adding extended hopper wings to the ST2.8 allowed the operators to feed the screen from the rear using a large Caterpillar 980 wheel loader, which also helped to increase productivity.
Results are impressive
“The ST2.8 has been a pleasant surprise,” says Damian Flores, quarry manager, GCC America. “The quick setup and simple controls allow the operator to start work quickly. The tonnage we have achieved with this screen has exceeded my expectations.”
The ST2.8 has been able to produce approximately 500 tons per hour of the limestone additive. By producing the additive themselves, rather than buying it from an outside source, the company is saving more than $20 a ton.
With this type of application, fines have typically been a huge bottleneck to production. “But the ST2.8 has a larger throw than most of other machines in its class,” says Greg Jones, crushing and screening manager, Wagner Equipment, “which allows it to produce a cleaner material.”
The ST2.8 also has more screening area on the second deck compared to other mobile screens in the same size range and this large screening area helps to improve fines separation. The unit’s powerful 75-kW (100-hp) Caterpillar C4.4 diesel engine meets the latest emissions regulations, and a new hydraulic system allows for lower fuel consumption compared to similar screens.
“Metso has done an amazing job of engineering this plant,” says Jones. “It is extremely simple, which takes very advanced engineering to pull off. There is excellent access to all of the hydraulic lines. The engine compartment is very roomy, the controls are extremely simple, and setup took us three or four minutes.”
GCC America is happy with the new Lokotrack ST2.8. “They have used scalping screens from different manufacturers in the past,” says Jones, “but when they tried the ST2.8, they said it was the best scalping screen they’ve ever operated and immediately asked about buying it.”
