The copper concentrator was designed and built by Fluor at a cost of $50 million. The concentrator has a capacity to process 33,000 tons of ore per day. The grinding mills convert the ore into approximately 230,000 tons annually of copper concentrate and 1,800 tons of molybdenum concentrate.
Island Copper's six autogenous grinding mills, each 32 feet in diameter and 14 feet in length, comprised the largest totally autogenous grinding circuit in the copper industry at the time.
An autogenous mill separates the mineral from the ore without rods, balls or other grinding media characteristics of conventional mills.