United States

Hall (Liberty) Project

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Mine TypeOpen Pit
  • Molybdenum
  • Copper
Mining Method
  • Truck & Shovel / Loader
Mine Life... Lock
SnapshotThe Hall Mine Complex (formerly Liberty) is centered on a porphyry Cu-Mo system in the Western flanks of the San Antonio Mountains.

Pathfinder Tonopah’s current exploration work is focused on understanding the molybdenum (Mo), copper (Cu) and silver (Ag) resources and their upside potential, reviewing their technical aspects, and evaluating how to most beneficially unlock their value.

Pathfinder Tonopah's copper, molybdenum and silver mine will provide a domestic supply of critical minerals from a historic mining site. Pathfinder Tonopah's SmartMine™ process will utilize leading technologies to mine responsibly, using on-site generated solar energy and an emphasis on efficiently multitasking resources in the mine complex.


Pathfinder Development Corp. 100 % Indirect
About 30 minutes north of Tonopah sits the Liberty Mine Complex, which was acquired by a company called Pathfinder Development Corp. in 2022.

Pathfinder Development Corporation is developing a portfolio of integrated opportunities, including critical mineral development through Pathfinder Tonopah and renewable energy generation through Pathfinder Energy Developments.

Deposit type

  • Vein / narrow vein
  • Porphyry


Base metal mineralization in the Liberty deposit consists of molybdenite (MoS2), chalcopyrite (CuFeS2), chalcocite (Cu2S), galena (PbS), sphalerite (ZnS), tetrahedrite (Cu8Sb2S7), and pyrite (FeS2). Molybdenite occurs mainly in 0.1" to 1.2"-wide quartz veins and veinlets in amounts that range from 0.1% to more than 40% by volume, typically as a selvage on vein walls. Molybdenite is also found in wider (+1.2”) quartz veins, but these are much less common in occurrence. Chalcopyrite and pyrite also are common but lesser vein/veinlet constituents. Galena, sphalerite, and lesser tetrahedrite occur with quartz in separate generations of base metal veins and veinlets that were emplaced at the end of each mineralization pulse (Shaver, 1991).

In general, molybdenum-bearing quartz veins and veinlets are more concentrated along the margins of the Hall stock, forming an irregular shell or sleeve of higher grade mineralization around a lower grade core. However, the intensity of quartz veining does not correlate directly with higher grade molybdenum – barren quartz veins are common within the deposit. Disseminated molybdenite is rare, occurring only in a 100'- to 200'- thick portion of the North Hall stock as replacements in biotite and/or plagioclase sites (Shaver, 1991). In addition to quartz, minor gangue minerals present in the veins and veinlets include fluorite, scheelite, tourmaline, gearksutite, and creedite, with siderite, dolomite, and calcite occurring as vug fillings.

The average grade (0.080% Mo) of the quartz monzonite porphyry (Kqmp) is higher than the average grade (0.064% Mo) of the orthoclase-rich intrusive rocks (Kamp). Part of the reason for this may be that the Kamp is more prevalent in the interior portion of the stock, while Kqmp is the dominant rock type along this portion of the stock margins (particularly the west and southwest sides), where quartz-molybdenum veining is more

Although chalcopyrite can occur with molybdenite in minor amounts in veins and veinlets within the main body of molybdenum mineralization in the Hall stock, it is much more prevalent in quartz veins in the metasediments on the northeast and east sides of the stock. Here it occurs in the remnant of the copper-dominant shell that originally surrounded the Hall stock before it was tilted and disrupted by faulting. In addition to chalcopyrite, chalcocite occurs as disseminations and as secondary coatings on pyrite within a roughly horizontal blanket of secondary supergene copper enrichment just below the bottom of oxidation. Definition of this supergene copper blanket is based on a combination of reverse circulation and diamond core drill holes that penetrate this portion of the deposit and on pit bench exposures from mining by Equatorial in 2000 – 2002. The thickness of the supergene blanket ranges from a few feet to 170 ft, and averages approximately 85 ft. Although generally horizontal and laterally continuous, the supergene blanket is locally offset by post-mineral faulting, particularly towards the main body of molybdenum mineralization to west. Copper grades in the supergene zone range from 0.06% Cu to 1.71% Cu, and average around 0.31% Cu. Beneath the supergene blanket, the chalcopyrite content of the sulfide zone is generally very low.



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CommodityUnitsAvg. AnnualLOM
Copper M lbs 9.6308
All production numbers are expressed as payable metal.

Production Costs

Credits (by-product) Molybdenum USD -2.49 / lb *  USD
Site cash costs (produced) Molybdenum USD 8.78 / lb *  USD
Site cash costs (produced) Molybdenum USD 6.29 / lb * **  USD
Total cash costs Molybdenum USD 10.4 / lb *  USD
Total cash costs Molybdenum USD 7.94 / lb * **  USD
Assumed price Molybdenum USD 15 / lb *  USD
Assumed price Copper USD 3.25 / lb *  USD
* According to 2014 study / presentation.
** Net of By-Product.

Operating Costs

OP mining costs ($/t milled) USD 4.43 *  USD
Processing costs ($/t milled) USD  ....  Subscribe
G&A ($/t milled) USD  ....  Subscribe
Total operating costs ($/t milled) USD  ....  Subscribe
* According to 2014 study.

Project Costs

MetricsUnitsLOM Total
Initial CapEx $M USD  ......  Subscribe
Sustaining CapEx $M USD  ......  Subscribe
OP OpEx $M USD  ......  Subscribe
Processing OpEx $M USD 1,745
G&A costs $M USD 232.8
Total OpEx $M USD  ......  Subscribe
Income Taxes $M USD  ......  Subscribe
Royalty payments $M USD  ......  Subscribe
Net revenue (LOM) $M USD  ......  Subscribe
After-tax Cash Flow (LOM) $M USD  ......  Subscribe
After-tax NPV @ 10% $M USD  ......  Subscribe
After-tax NPV @ 8% $M USD  ......  Subscribe
After-tax IRR, %  ......  Subscribe
After-tax payback period, years  ......  Subscribe

Heavy Mobile Equipment


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Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Dec 11, 2023


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