• Data Access
  • Your Email  
  • Your Email  
Keep me signed in.
Forgot your password?
Close
  • Forgot Your Password?
  • Enter the email you signed up with and we'll email it to you.
  • Your Email  
Close
Back
MDO
Mining Data Solutions
  • Home
  • Database
  • Subscribe
  • Sign In
  • Sign In
United States
Gunnison Project

This page is not tailored to
devices with screen width under 750 px.
 Location:
83 km E from Tucson, Arizona, United States

  Project Contacts:
Concord Place, Suite 300 - 2999 North 44th Street
Phoenix
Arizona, United States
85018
Phone  ...  Subscription required
EmailEmail
WebsiteWeb
Additional Resources for Suppliers & Investors
Drill results over 30 g/t Au
Stay on top of recent discoveries.
Search drill results by commodity and grade.
Largest mines in the Americas
Mining and mill throughput capaciites.
Full profiles of select mines and projects.
Deepest underground mines
Shaft depth and mill throughput data.
Full profiles of select mines and projects.
Heavy mobile equipment
HME type, model, size and quantity.
Full profiles of select mines and projects.
Permitting and construction projects
Projects at the permitting or construction stage. Full profiles of select projects.
Mines with remote camps
Camp size, mine location and contacts.
Full profiles of select mines and projects.
Mines & projects in United States
A list of country's mines and projects.
Full profiles of select mines and projects.
  • Overview
  • Owners
  • Geology
  • Mining
  • Processing
  • Production
  • Reserves
  • Costs & Financials
  • Fleet
  • Personnel
  • Filings & News

Thank you for browsing through mine profiles compiled by the Mining Data Online team.

Would you like to subcribe or schedule a Demo?
  • Name:
     
  • Company:
     
  • Position:
     
  • Phone:
  • Email:
  • Message:

Overview

StagePermitting
Mine TypeIn-Situ
Commodities
  • Copper
Mining Method
  • Solution mining
Mine Life24 years (as of Jan 1, 2022)
The Gunnison Project is a low-cost, environmentally friendly in-situ recovery copper extraction project that is permitted to 125 million pounds per year of copper cathode production. Excelsior announced the start of construction in December 2018, and the completion of the construction phase in December 2019, including the wellfield drilling and the supporting infrastructure. Upgrades to the adjacent Johnson Camp mine (“JCM”) Solvent Extraction and Electrowinning (“SX-EW”) plant were also completed in December 2019. The injection of mining fluids to the wellfield for copper production started on December 31, 2019 and the Company began the start-up and commissioning phase of the project in January 2020. On April 9, 2020 a decision was made to place the project on Care and Maintenance in response to the COVID-19 global pandemic. On August 12, 2020 the Company announced that a small-scale restart had commenced.


Owners

Source: p. 14
CompanyInterestOwnership
Excelsior Mining Corp. 100 % Indirect
Excelsior Mining Arizona, Inc. 100 % Direct
The Gunnison Project is held by Excelsior Mining Corp. through is wholly-owned subsidiaries Excelsior Mining Arizona, Inc. (Excelsior Arizona) and Excelsior Mining JCM, Inc. (Excelsior JCM).

Contractors

Subscription required - Subscription is required.


Deposit Type

  • Skarn


Summary:

The Gunnison Project (North Star) lies on the eastern edge of the Little Dragoon Mountains.

The North Star copper deposit is a classic copper skarn (Einaudi et al, 1980 and Meinert et al, 2005). Skarn deposits range in size from a few million to 500 million tonnes and are globally significant, particularly in the American Cordillera. They can be stand- alone copper skarns, which are generally small, or can be associated with porphyry copper deposits and tend to be very large. The North Star deposit is large, at the upper end of the range of size for skarn deposits, and is likely associated with a mineralized porphyry copper system that has not been discovered.

Copper skarns generally form in calcareous shales, dolomites and limestones peripheral or adjacent to the mineralized porphyry. Copper mineralizing hydrothermal fluids are focused along structurally complex and fractured rocks and convert the calcareous shales and limestones to andradite rich garnet assemblages near the intrusive body, and to pyroxene and wollastonite rich assemblages at areas more distal to the stock. Retrograde hydrothermal fluids produce actinolite-tremolite-talc-silica-epidote-chlorite assemblages that overprint earlier garnet and pyroxene. The mineralization is typically pyrite -chalcopyrite-magnetite proximal to the mineralizing porphyry and chalcopyrite-bornite more distally from the body. The copper-gold porphyry and skarn model by Sillitoe (1989) is being used as a conce ........


Mining Methods

  • Solution mining


Summary:

Excelsior proposes to use the In-Situ Recovery (ISR) method to extract copper from oxide mineralization located within the North Star deposit. ISR was chosen based on the fractured nature of the host rock, the presence of water saturated joints and fractures within the ore body, copper mineralization that preferentially occurs along fracture surfaces, the ability to operate in the vicinity of Interstate 10, and to avoid the challenges of open pit mining in an area with alluvium overburden thickness ranging from approximately 300 feet to 800 feet.

In the ISR process, a low pH raffinate solution (“lixiviant”) is injected into the ore body via a series of injection wells. As the lixiviant migrates through the joints and fractures within the mineralized bedrock, copper is dissolved. This pregnant leach solution (PLS) is recovered by a series of recovery wells that surround each respective injection well.

The PLS is pumped to the surface where the copper is stripped from the solution using the solvent extraction/electrowinning (SX-EW) process. The SX-EW process begins with the SX plant extracting and concentrating the dissolved copper from the PLS, after which the EW plant reduces the concentrated copper to copper cathode. Once the copper is recovered by SX, the barren solution is re-acidified with sulfuric acid to create new lixiviant which is pumped back to the well field and re-injected. The total volume of lixiviant injected and PLS extracted will remain ........


Crushing and Grinding


Processing

Flow Sheet: Subscription required

Summary:

- subscription is required.


Projected Production:

CommodityUnitsAvg. AnnualLOM
Copper M lbs 1252,154
All production numbers are expressed as cathode.

Operational Metrics:

Metrics
Annual production capacity  ......  Subscription required
* According to 2022 study.
Subscription required - Subscription is required.

Reserves at October 1, 2016:
The Mineral Resources are estimated at a 0.05% TCu cut-off for oxide and transitional, 0.30% TCu cut-off for sulfide.

The Mineral Reserve are estimated at a 0.50% TCu cut-off.

CategoryTonnage CommodityGradeContained Metal
Probable 782.2 M tons Copper 0.29 % 4,505 M lbs
Measured 200.7 M tons Copper 0.36 % 1,439 M lbs
Indicated 710.8 M tons Copper 0.27 % 3,875 M lbs
Measured & Indicated 911.6 M tons Copper 0.29 % 5,315 M lbs
Inferred 240.9 M tons Copper 0.22 % 1,070 M lbs

Commodity Production Costs:

CommodityUnitsAverage
Cash costs Copper USD  ......  Subscription required&nbs
Total cash costs Copper USD  ......  Subscription required&nbs
Assumed price Copper USD  ......  Subscription required&nbs
* According to 2022 study / presentation.
Subscription required - Subscription is required.

2022 Study Costs and Valuation Metrics :

MetricsUnitsLOM Total
Initial CapEx $M USD  ......  Subscription required
Sustaining CapEx $M USD  ......  Subscription required
Closure costs $M USD  ......  Subscription required
Total CapEx $M USD  ......  Subscription required
Well Field OpEx $M USD  ......  Subscription required
G&A costs $M USD 199.5
Total OpEx $M USD  ......  Subscription required
Income Taxes $M USD  ......  Subscription required
Royalty payments $M USD  ......  Subscription required
Gross revenue (LOM) $M USD  ......  Subscription required
Net revenue (LOM) $M USD  ......  Subscription required
Pre-tax Cash Flow (LOM) $M USD  ......  Subscription required
After-tax Cash Flow (LOM) $M USD  ......  Subscription required
Pre-tax NPV @ 10% $M USD  ......  Subscription required
Pre-tax NPV @ 7.5% $M USD  ......  Subscription required
After-tax NPV @ 10% $M USD  ......  Subscription required
After-tax NPV @ 7.5% $M USD  ......  Subscription required
Pre-tax IRR, %  ......  Subscription required
After-tax IRR, %  ......  Subscription required
Pre-tax payback period, years  ......  Subscription required
After-tax payback period, years  ......  Subscription required
Subscription required - Subscription is required.


Proposed Heavy Mobile Equipment as of March 11, 2022:
HME TypeSizeQuantity
Deck & Boom Trucks ....................... Subscription required
....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required
Subscription required - Subscription is required.

Mine Management:

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Jan 9, 2023
Subscription required - Subscription is required.


Corporate Filings & Presentations:

DocumentYear
Annual Information Form 2022
Corporate Presentation 2022
Corporate Presentation 2022
Management Discussion & Analysis 2022
Pre-Feasibility Study Report 2022
Pre-Feasibility Study Report 2022
................................... Subscription required 2021
Feasibility Study Report 2017
Pre-Feasibility Study Report 2016
Subscription required - Subscription is required.

Subscription required - Subscription is required.

Terms of Use Privacy Policy © 2017-2023 MDO Data Online Inc.