ABB commissions the most powerful gearless mill drives ever built

ABB (Baden, Switzerland; www.abb.com) has commissioned automation and power equipment that increases production at Boliden AB’s (Stockholm, Sweden; www.boliden.se) Aitik copper concentrator plant, located near Gällivare in northern Sweden. Aitik is Sweden’s largest mine and has now become a global industry benchmark in mine efficiency since its completion in August 2010. The new copper concentrator plant has completely replaced the old grinding plant, which will be closed down later this year. Two gearless mill drives (GMD) power two new 38-ft (11.6-m) autogenous grinding mills. At 22.5 MW each, the mill drives are the most powerful in the world. They drive mills each with a capacity to grind about 2,200 ton/h of ore, expanding production capacity to 36 million ton/yr of ore (from 18 million ton/yr). An autogenous mill uses large pieces of ore to grind down smaller pieces by impact in a large rotating drum. The autogenous mill and its GMD is not only one of the largest installations (the ring motor is almost 20-m high), it is also one of the pivotal applications in a concentrator plant, grinding the ore into small particles with a combination of brute strength and advanced technologies on both the mill and motor side. The…