(Updated February 4th, 2021)
The past-producing Wind Mountain gold/silver project is located approximately 160km northeast of Reno, Nevada in a sparsely populated region with excellent logistics, including county-maintained road access and a power line to the property. A previous owner, AMAX Gold recovered nearly 300,000 ounces of gold and over 1,700,000 ounces of silver between 1989 and 1999 from two small open pits and a heap-leach operation (based on files obtained from Kinross Gold, successor in interest to AMAX Gold). Rio Fortuna Exploration (U.S.) Inc., a wholly owned US subsidiary of Bravada Gold Corporation, acquired 100% of the property through an earn-in agreement with Agnico-Eagle (USA) Limited, a subsidiary of Agnico-Eagle Mines Limited, which retains a 2% NSR royalty interest, of which 1% may be purchased.
For a 10 minute detailed video presentation on Wind Mountain, click here
A Technical Report for an independent Preliminary Economic Assessment (PEA) and resource estimate was conducted by Mine Development Associates (MDA) of Reno. The PEA assumes open-pit, contract mining with conventional trucks and shovels, run-of-mine leaching, and a base-case price of US$1,300 per ounce of gold and $24.42 per ounce of silver. The base-case economic model (1) is summarized below in US dollars and Imperial units (some values rounded):
Resource inside the pits = 42.1 million short tons of Indicated Resource @ 0.011 oz Au/t & 0.26 oz Ag/t, and 2.2 million short tons of Inferred Resource @ 0.008 oz Au/t & 0.18 oz Ag/t, both utilizing a 0.006 oz Au/t cutoff
Gold & Silver Ounces mined = 465,000 oz Au & 11,198,000 oz Ag (516,000 oz Au-eq(2))
Gold & Silver Ounces produced = 288,000 oz Au & 1,680,000 oz Ag (320,000 oz Au-eq(2))
Waste: Ore Strip ratio = 0.71:1
Capital = Initial capital of $45.4 million with $18.4 million sustaining capital
Mine Life = approximately 7 years of mining with 2 additional years of residual leaching & rinsing
Payback Period = 2.2 years
Life-of-mine cash cost(3) = $859 per ounce Au
Total Pre-Tax cost(3) = $1,080 per ounce Au
Pre-Tax IRR = 29%; After-Tax IRR = 21%
Pre-tax NVP@5% = $42.9 million; After-Tax NPV@5% = 26.5 million
(1) Canadian NI 43-101 guidelines define a PEA as follows: “A preliminary economic assessment is preliminary in nature and it includes inferred mineral resources that are considered too speculative geologically to have the economic considerations applied that would enable them to be classified as mineral reserves, and there is no certainty that the preliminary assessment will be realized. Mineral resources that are not mineral reserves do not have demonstrated economic viability.”
(2) Expected recoveries were incorporated to convert silver to gold equivalent (Au-eq) at 220Ag:1Au ($1,300 x 62% divided by $24.42 x 15%)
(3) Pre-tax costs include estimated Nevada Net Proceeds taxes, but not corporate income tax. After tax includes corporate taxes, silver is treated as a by-product credit.
Sensitivity studies by MDA indicate that gold and silver prices 30% higher in the same modeled pit and at the same recovery rates ($1,690/oz Au and $31.75/oz Ag) would increase the IRR to 74% and the NPV@5% to $136.2 million. Gold and silver prices that are 20% lower ($1,040/oz Au and $19.54/oz Ag) would result in the model being uneconomic at an NPV@5%. Sensitivities of the model to capital and operating costs are also provided. MDA notes that additional studies such as additional metallurgical studies to evaluate crushing higher-grade portions of the deposit and grid drilling to delineate economic portions of the previously mined “waste rock”, which are given no value in the current model, could further enhance the economics of known mineralization. Approximately 43% of the pre-mining strip in the PEA model consists of “waste rock”, and MDA is optimistic that with further drilling and sampling a portion of this material’s grade and tons could be quantified for economic evaluation.
Mine Development Associates compiled the technical report. Thomas Dyer, P.E. is a Senior Engineer for MDA and is responsible for sections of the technical report involving mine designs and the economic evaluation, and Steven Ristorcelli, C.P.G., is a Principal Geologist for MDA and is responsible for the sections involving the Mineral Resource estimate. These are the Qualified Persons of the technical report for the purpose of Canadian NI 43-101, Standards of Disclosure for Economic Analyses of Mineral Projects.
Exploration continues for additional mineralization on the Property. The Feeder target is interpreted as the likely source of gold/silver-bearing hydrothermal fluids that deposited disseminated gold/silver previously mined in open pits by Amax Gold, as well as the remaining Resources defined by Bravada. Evidence for the target concept is from Amax’s shallow condemnation drill holes and from Bravada’s geological mapping, geochemical sampling, magnetic geophysics, and nearby 2017/18 deep drill holes. Disseminated gold and silver mineralization on the Wind Mountain property is exposed over a strike length of more than 6km, indicating a robust gold system that spread laterally over a large area within permeable host sediments; however, a high-grade “feeder” zone has not been discovered to date and that is the objective of recent drilling.