ABB announced that it recently won a contract from Kinross Gold for the delivery of three gearless mill drive (GMD) systems to be installed at the Tasiast gold mine. Tasiast is an open-pit operation located in north-western Mauritania, Africa, and is situated approximately 300 km north of the capital Nouakchott.

The three ABB GMDs are part of an expansion project that is scheduled to go into commercial

operation in early 2014. The Tasiast open-pit mine will feed both an existing 8,000 metric-ton-per-day (mt/d) plant and a new 60,000-mt/d plant. The existing Tasiast mine began commercial operations in 2008. The expansion plant is a conventional gold cyanidation plant, consisting of primary crushing, grinding, gravity separation, carbon-in-leach cyanidation and cyanide destruction.

ABB’s scope of supply consists of three complete GMD systems including transformers, ring motors and E-house. One 26 megawatt GMD system will be installed for a 40-foot diameter SAG mill, while two 20.5 megawatt GMD systems will be installed to drive two 27-foot diameter ball mills. In addition, Kinross ordered the new ABB GAP-Watch for each system. GAP-Watch is a unique rotating air gap monitoring system for ring motors. This latest ABB GMD innovation is designed to constantly measure the distance between a rotor pole and the stator of the ring motor (air gap) while the mill is rotating. The measurements provide a real-time picture of the air gap along the complete circumference of the motor, leading to increased reliability of the GMD system.