As Siemens Drive Technologies Division celebrates 500 years of gearless mill drive operation (combined total of installations) it is delivering the gearless drive technology for two new mills for the Toromocho mine in the Peruvian province of Yauli. The order comes from Minera Chinalco Perú, a subsidiary of Aluminum Corp of China (CHINALCO).

In future, two gearless mill drives will be used in the new production line with one SAG mill and one ball mill. Thus, 1 Mt of copper concentrate, 10,000 t of molybdenum and 4 Moz of silver oxide can be produced annually.

The Toromocho mine in Morococha lies at an altitude of around 4,600 m above mean sea level and is situated just less than 150 km from the capital city of Lima. Minera Chinalco Perú is aiming to boost the mine’s productivity with a new production line. At this high altitude, special requirements were applied to the mill drives. Not only must they be able to cope with the rugged mine environment, they must also fulfill the special requirements of the remote, difficult to access mine site topography.

Siemens will be delivering two gearless mill drives to meet these special Toromocho requirements. In future, the 36’ SAG mill of the new production line will be operated with a 13.5-MW. A further gearless mill drive with 22 MW output will ensure equally efficient and reliable driving of a ball mill with an inner diameter of 28’. Gearless drive systems are distinguished by their high efficiency of up to 4% better than conventional drives, low maintenance effort and a high availability of over 99%. Complex maintenance operations at an altitude of 4,600 m can thus be avoided, which affords time and cost savings.