Hudbay’s US properties are the Rosemont project, located in Arizona, and the Mason project, located in Nevada.

The Mason deposit, acquired in late 2018, is one of the largest undeveloped copper resources in the Americas. It is similar in scale to Constancia and Rosemont.

In production, the Rosemont project will be one of the largest copper mines in the United States, with an expected mine life of 19 years.

The copper at Rosemont will support a cleaner, interconnected economy by supplying critical materials in accordance with some of the world’s most stringent labour and environmental standards.

In July 2019, the US District Court for Arizona issued a ruling that vacated the Final Record of Decision (FROD) issued by the US Forest Service. As a result, our ability to move ahead with building Rosemont is suspended for the time being. Simply put, the judge ruled that the decision to issue the FROD was based on an incorrect interpretation of mining claims.

We have appealed the ruling. Hudbay believes that the Court misinterpreted federal mining laws and Forest Service regulations as they apply to Rosemont.

The metal from Rosemont will be a vital part of technology in daily life, the green economy and Arizona’s future.

Utilizing leading-edge mining technologies, Rosemont will help define safe and sustainable 21st-century mining practices that will support America’s clean energy economy. Rosemont is striving to raise the bar for what it means to safely and sustainably mine copper and other essential minerals – to minimize impacts to the landscape and water and to enrich partner communities in ways that outlast the course of mining operations.

Number of Employees Expected During Operation


Expected Mine Life

Rosemont: 19-year mine life


Rosemont will use the dry-stack method of tailings storage. Dry stack eliminates storage ponds, uses 50% to 60% less water than similarly sized mines, and extracts about 85% of the water that is used, for use again.

Key Production Metrics

$1.921 billion capital cost
15.5% after-tax unlevered IRR at $3.00/pound copper
127,000 tonnes of annual copper production in first 10 years
Cash cost of $1.14/pound net of by-product credits, in first 10 years


In production, water consumption at the Rosemont mine will be among the lowest in the world per pound of copper produced. Rosemont will replace all the water used at the operation and has already purchased and stored approximately 45,000 acre-feet of water, equivalent to the amount Rosemont will use in its first eight years. This water will be returned to the Rosemont-area aquifer through recharge of the Central Arizona Project (CAP), a water replenishment program. Additionally, as part of the project, we expect to contribute $28 million toward building an eight-mile pipeline and water recharge facility that will bring CAP water to the region.

Of water used for the operation of Rosemont will be replaced


We are part of the communities in which we operate. The permitting and public comment period for Rosemont provided us with a greater understanding of nearby communities’ priorities, and these are reflected in Rosemont’s numerous commitments to contribute to the region’s long-term economic prosperity and well-being. Once the mine is in operation, a $25 million trust will be dedicated to conservation, recreation, cultural and environmental projects and education. Additionally, an annual contribution of $500,000 for 25 years (a total of $12.5 million) will be made to support community giving. A total of $12.5 million will be prioritized to support education, social services, job training, and organizations that support military personnel and veterans.

$25 million
For conservation, recreation, cultural and environmental projects and education
$12.5 million
For community giving over 25 years


Navigable Waters of the U.S.


After a construction decision is approved, Rosemont will prioritize hiring from within local communities and will require up to 2,500 workers during the peak construction period. We continue to engage with local businesses, organizations and universities to identify resources, local talent pools and opportunities to build a pipeline of potential future employees. In production, Rosemont is expected to directly create over 500 full-time jobs. Annual wages for direct employees are expected to average more than twice the current median annual income in Pima County.

Jobs expected during the peak of construction at Rosemont
Full-time jobs once production begins and for the duration of the estimated 19-year mine life

Reserves and resources - Rosemont

Rosemont Project

Mineral Reserve Estimates - January 1, 2020(1)(2)(3)
Tonnes Cu
Proven 426,100,000 0.48 0.012 4.96
Probable 111,000,000 0.31 0.010 3.09
Total proven and probable 537,100,000 0.45 0.012 4.58

Note: totals may not add up correctly due to rounding.
1 Blocks were classified as Proven or Probable in accordance with CIM Definition Standards 2014
2 Mineral resources are constrained within a computer generated pit using the Lerchs-Grossman algorithm. Metal prices of US$3.15 per pound copper, US$11.00 per pound molybdenum and US$18.00 per ounce of silver were used. Metallurgical recoveries of 90% copper, 63% molybdenum and 75.5% silver were applied. No metallurgical recovery of molybdenum and silver from oxide ore is projected.
3 Based on 100% ownership of the Rosemont project.

Mineral Resource Estimates(1)(2)(3) Tonnes Cu
Measured 161,300,000 0.38 0.009 2.72
Indicated 374,900,000 0.25 0.011 2.60
Total Measured & Indicated 536,200,000 0.29 0.011 2.64
Total Inferred 62,300,000 0.30 0.010 1.58

1 Mineral resources that are not mineral reserves do not have demonstrated economic viability. Please refer to Schedule A “Glossary of Mining Terms” in our Annual Information form dated March 29, 2020.
2 Mineral resources are constrained within a computer generated pit using the Lerchs-Grossman algorithm. Estimates of mineral resources are based on the following long-term metals prices: $3.15 per pound of copper; $11.00 per pound of molybdenum; and $18.00 per ounce of silver. Metallurgical recoveries of 85% copper, 60% molybdenum and 75% silver were applied to sulfide material. Metallurgical recoveries of 40% copper, 30% molybdenum and 40% silver were applied to mixed material. A metallurgical recovery of 65% for copper was applied to oxide material. NSR was calculated for every model block and is an estimate of recovered economic value of copper, molybdenum, and silver combined. Cut-off grades were set in terms of NSR based on current estimates of process recoveries, total processing and general and administrative operating costs of $5.70 per ton for oxide, mixed and sulfide material.
3 Based on 100% ownership of the Rosemont project.

Reserves and resources - Mason

Mineral Resource Estimates - January 1, 20211,2,3 Tonnes Cu Grade(%) Mo Grade(%) Au Grade(g/t) Ag Grade(g/t)
Measured 1,417,000,000 0.29 59 0.66 0.006
Indicated 801,000,000 0.30 80 0.57 0.008
Total Measured and Indicated 2,219,000,000 0.29 67 0.63 0.007
Inferred 237,000,000 0.24 78 0.73 0.008

1 Mineral resource estimates that are not mineral reserves do not have demonstrated economic viability. Mineral resource estimates do not include factors for mining recovery or dilution.
2 Metal prices of $3.10 per pound copper, $11.00 per pound molybdenum, $1,500 per ounce gold, and $18.00 per ounce silver were used to estimate mineral resources.
3 Mineral resource estimates are reported as 20 metres by 20 metres by 15 meters blocks above cut-off using a minimum NSR per tonne of $6.25 and a cut-off grade of 0.20% copper.