Resolution Copper Mine — No. 9 Shaft Deepening project

Deposit is nearly 1.3 miles below the earth’s surface.

Deepest underground mine shafts in the US.

Anticipated production rate of 51,000 to 115,000 ore tpd.

Potential to supply 25% of the US copper demand.

Challenges

The Resolution copper deposit lies nearly 7,000 feet (or 1.3 miles) below the earth’s surface. It is one of the world's largest undeveloped copper deposits.
The most viable way to recover the resource is by going deep underground, and to do so, Resolution is using the block caving process—one of the most economical underground mining methods available for this type of large, deep deposit.
Originally constructed in 1971, the No. 9 mine shaft sat idle for nearly 20 years.
The No. 9 Shaft Deepening project will rehabilitate the shaft, sink it to approximately 7,000 feet, and link it with the newer No. 10 shaft, which was completed in 2014.
The main challenge at Resolution is the high rock temperature and water inflows, which can escalate to 140°F.

Following earlier study phases, was awarded the engineering, project and construction management (EPCM) contract to refurbish the existing No. 9 shaft and deepen it to the same level as the No. 10 shaft.
The No. 9 Shaft Deepening project consists of the rehabilitation of the shaft from the surface to 4,823 feet below surface and the deepening of the shaft by 2,022 feet, utilizing the blind sinking methodology. It includes the excavation of five stations, three levels, and two pump stations.
Reconfigured, strengthened, and upgraded the headframe and hoisting equipment.
Reconfigured and upgraded the underground ventilation system to support new demands and the efficient operation of both personnel and equipment.
Upgraded the mine dewatering system to meet the new demands.
Installed new diesel generators for back-up power.

Phase 2 of the project, the deepening works, will sink the shaft to a final depth of 6,845 feet below the collar.
The existing No. 10 Shaft at Resolution Mine is the deepest in the United States and the No. 9 Shaft will be at the same depth at completion.
Connecting the shafts will provide a second means of egress between the two shafts as well as improve ventilation.
Current life-of-mine studies are focusing on a production rate in the range of 51,000 to 115,000 ore tones per day at an anticipated ore grade of >1.5% copper.
Over 350,000 hours have been expended on this challenging work to-date without a Lost-Time Injury (LTI).

6,845 feet, final depth below the collar
4,750 feet of shaft rehabilitated
1,284 cubic yards of concrete placed at 15 old mine level stations to permanently seal them and sections of shaft liner that required repairs
450 shaft guide steel sets (950 tons) removed
145 ring set liner plates removed at old level stations

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