|Lundin Mining’s $400 million Eagle Ni-Cu project in upper Michigan includes the underground mine and surface facilities shown here, and a 2,000-t/d concentrator. (Photos courtesy of Lundin Mining)|
Lundin Mining said in mid-July that it had reached the final stages of construction and mine startup at the Eagle nickel-copper project in Michigan’s Upper Peninsula. The project includes the underground Eagle mine, 53 km northwest of Marquette, Michigan; and the Humboldt mill, 60 km west of Marquette. The mill is a former iron-ore processing facility that is being converted to a concentrator that will process 2,000 metric tons per day (mt/d) of Eagle ore.
Eagle ore is trucked 105 km from the mine to the mill. The ore-haulage route passes through the city of Marquette. The Marquette City Commission approved an ore-haulage route agreement in May. Ore shipments to the mill began in early July.
The Eagle project is scheduled to produce its first concentrates early in the fourth quarter of 2014 and to reach full commercial production during the second quarter of 2015. Annual production over the first three full years of operation is planned at about 23,000 mt/y of nickel and 20,000 mt/y of copper in separate concentrates, plus precious metals and cobalt by-product credits. Life-of-mine production of metal in concentrates over an eight-year mine life is expected to average about 17,000 mt/y each for nickel and copper at an average cash cost of $2.50/lb of nickel. Sales agreements are in place for a significant portion of the production.
Construction of surface facilities at the Eagle mine site was 100% complete as of mid-July, and underground development was on schedule to allow production to rampup as planned. Mill site construction was more than 90% complete, and commissioning with first ore feed was expected to start within eight weeks. Staff recruitment was 100% complete.
The total capital cost forecast for the Eagle project remains at $400 million, with Lundin expecting final costs to be at or slightly under budget.
Eagle is a relatively shallow underground mine, with access via a ramp. The mine employs transverse bench-and-fill stoping, using both cemented and uncemented rockfill.
|The Eagle project’s Humboldt mill is a former iron-ore processing facility converted to a concentrator. It will process ore trucked 105 km from the mine.|
Two ventilation shafts are in place, with the downcast shaft also equipped for emergency egress. Ore from the mine is stored in a covered coarse ore stockpile prior to transport to the Humboldt mill site.
The Eagle deposit is a high-grade magmatic sulphide deposit containing nickel and copper mineralization and minor amounts of cobalt, gold and platinum group metals. The economic minerals associated with the deposit are predominately pentlandite and chalcopyrite.
In-fill and step-out exploration work is ongoing from the Eagle underground mine. Surface drilling also is in progress on near-mine targets, with priority being given to step-out drilling on the Eagle East deposit, an ultramafic intrusion 1 km east of the Eagle mine.
Lundin acquired the Eagle project from Rio Tinto for $350 million in cash in a transaction that closed in July 2013.