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Mining 101

Geology

The Eagle deposit was formed during the Midcontinent Rift tectonic event 1.1 billion years ago. This rifting, or breaking apart, separating, and thinning of the Earth’s crust allowed magma deep within the Earth to rise up through the crust and cool as igneous bodies. The Eagle deposit was the result of at least three different intrusions of magma rich in metals. As the magma cooled, nickel and copper minerals crystallized into a solid ore body. The bottom of the ore body sits roughly 1,000 feet deep and measures to be roughly 6 acres in size. Eagle has two ore types; massive and semi-massive sulfide. Massive sulfide is about 6.5 percent nickel and 3.8 percent copper. Semi-massive contains about 1 percent nickel and 1 percent copper. The Eagle deposit is high-grade nickel and copper, but also contains trace amounts of cobalt, platinum, palladium, silver, and gold.

Mining

At Eagle Mine, underground mining employs long-hole stoping techniques to recover the ore. The deposit is accessed via a 1-mile long decline tunnel measuring about 18 feet in diameter. Ore is transported to the above ground Coarse Ore Storage Area (COSA) by low-profile, 45-ton loaders. Inside the COSA, a front-end loader will fill road haul trucks with ore on average 18-24 inches in size. Truckloads are covered before passing through the truck wash and continuing off-site to travel approximately 66 miles to the Humboldt Mill. Eagle will be mined from the bottom –up and backfilled with a mix of rock, aggregate, and cement as the levels are mined.

Blast

Muck

Backfill

Milling

Drill

A stope is a section of the ore deposit that is going to be mined for minerals. The face of the stope is prepped and drill holes are strategically placed. Stopes are roughly 90 feet tall, 30 feet wide, and the depth depends on the area of the ore body.

Crush

Three stages of crushing reduce the ore from 18 inches, to four inches, and finally to less than half inch. Crushed ore is stored in three fine ore bins, each having a capacity of 2,000 tons, before being sent to the grinding circuit.

Grind

Float

Press

Transportation

Health & Safety

Safety is not about numbers – it’s about people. Our goal is an injury-free workplace where everyone goes home safe each and every day. Our approach begins with an effort to eliminate hazards from our operations. We spend a significant amount of time training our employees and contractors to stay safe and healthy on the job site. While on-site, we ensure everyone wears proper Personal Protective Equipment (PPE) to guard them against any hazards that they may come in contact with. We’ve built a culture where employees and contractors consider their own safety as well as the safety of those around them. We work every day to maintain our goal of zero harm.

The Products We Produce

Nickel

From medical equipment to transportation, nickel is found in many of the products that make modern life possible. Manufacturers often prefer to use nickel alloys over other materials because they are more resistant to corrosion, tolerant of high and low temperatures, strong and contain magnetic and electronic properties. At the end of their useful life, about 25 to 35 years, nickel products are easily recycled for future use. In fact, about half of the nickel in modern stainless steel products comes from recycled sources. Eagle will produce 360 million pounds of nickel.

Copper

Today copper can be found in many of the products that we use every day including home appliances, vehicle parts, and electrical components. Copper can easily be shaped, molded, rolled into sheets, or drawn into thin wire. It does not easily rust and is an excellent conductor of electricity and heat. In many respects, modern life would not be possible without copper. Eagle will produce 295 million pounds of copper.