Trilogy Metals has announced the updated results of its Feasibility Study (2023 FS) for the Arctic copper-zinc-lead-silver-gold project (Arctic Project) in the Ambler mining district in north-western Alaska.
The Arctic project is held by Ambler Metals, a 50-50 joint venture between Trilogy and a wholly-owned subsidiary of Australian mining and metals company South32.
The Canadian mining company said that the 2023 FS results are updated in response to its regulatory requirements, and neither South32 nor Ambler Metals reviewed them.
Trilogy has contracted Wood Canada to complete the mineral resources and mineral reserve estimation and mine planning services for the project.
In addition, SRK Consulting was hired to complete pit geotechnics and hydrogeology, tailings and waste design, hydrology and water management studies, and Brown and Caldwell for the water treatment facility.
Trilogy Metals president and chief executive officer Tony Giardini said: “Arctic continues to be an extremely robust project even in a high inflationary environment.
“We have updated the capital and operating costs to reflect high-inflation and supply-chain challenges and yet the economics continue to stand out.”
According to the updated FS results, Arctic is viable for establishing a conventional 10000t/d capacity copper/zinc/lead/silver/gold mine and mill complex, with over 13 years of mine life.
It estimates average annual production of 149 million pounds of copper, 173 million pounds of zinc, 26 million pounds of lead, 32,538 ounces of gold and 2.8 million ounces of silver.
The 2023 FS uses long-term metal prices of $3.65/lb for copper, $1.15/lb for zinc, $1.00/lb for lead, $1,650/oz for gold and $21.00/oz for silver in its economic analysis.
This increases the operating costs by 18% from the 2020 feasibility study to $59.83/t milled, and initial capital expenditure from $905.6m in 2020 to $1.18bn.
The average recoveries are expected to be 92.1% for copper, 88.5% for zinc and 61.3% for lead, based on the metallurgical work on the sulphide mineralisation.
