The Siemens Drive Technologies Division has received an order from ThyssenKrupp Robins (Greenwood Village, Colorado, USA) to supply the gearless drive system for the overland conveyor system in the Las Bambas copper mine in Peru. The owner of the mine is Xstrata Copper (Brisbane, Australia). Las Bambas will be the second Xstrata Copper mine in Peru to use gearless drives from Siemens on its overland conveyors. The first Peruvian copper mine that is utilizing Gearless Drives is the Antapaccay Mine, which began commercial operations at the beginning of November 2012. When compared to conventional drive systems, gearless drives not only have higher efficiency, availability, and reliability, but also lower maintenance requirements. Start-up of the new conveyor system at Las Bambas is scheduled for 2014.
The overland conveyors at Xstrata's Las Bambas copper mine are being designed and supplied by ThyssenKrupp. Each of the two overland conveyors is approximately 2.5 kilometers long and will transport ore from the mine to the processing plant. The belts will be 1,830 millimeters wide, travel at 6.5 meters per second, and are designed to transport approximately 9,400 tons of material per hour. The Siemens drive systems for each of the two overland conveyors comprise two low-speed synchronous motors – each with a total power of 4,400 kilowatts – and the associated Sinamics SL150 cycloconverters. This gearless drive solution has a number of advantages over the combination of high speed motor and gearbox drives usually used on conveyor systems. The size of the motor is not limited by the size of gearbox available, thus eliminating the necessity to install multi-motor drives. The power required to drive a belt can be provided by just one drive per belt pulley. This enables the size of the electrical room to be reduced, thus saving space and weight. The elimination of a whole series of mechanical and electrical components increases the reliability.