The Keno Hill Silver District has a rich history as one of the world’s highest-grade silver districts. It is located 350 km north of Whitehorse, in Canada’s Yukon Territory, within the traditional territory of the First Nation of Na-Cho Nyak Dun and comprises 233 square km characterized by numerous mineral occurrences and more than 35 mine sites with a history of past production. The District has year-round access via highway from Whitehorse to Mayo and is connected to the national power grid.
According to the Yukon government’s Minefile database, between 1913 and 1989 the District produced in excess of 200 Moz silver from over 5.3 Mt of ore with average grades of 44 oz/t, making it the second-largest historical silver producer in Canada. Keno Hill continues to boast significant Mineral Resources at grades far higher than most of the world’s primary silver producers.
In 1989, with falling metal prices and increased environmental standards, the former owners of Keno Hill, United Keno Hill Mines Limited, terminated their mining activities in the District.
Alexco owns the majority of the District and has been actively developing it since 2006 under a unique contractual arrangement with the Government of Canada whereby Alexco can produce from historic and newly discovered deposits within the District while also undertaking reclamation activities to remediate historic environmental impacts. The District’s quartz mining claims and quartz mining leases are held by one of two wholly owned subsidiaries of Alexco: Elsa Reclamation & Development Company Ltd. or Alexco Keno Hill Mining Corp.
Alexco built and operated the Bellekeno silver mine, one of the world’s highest-grade silver mines with a production grade of up to 1,000 g/t silver. Bellekeno commenced commercial production at the beginning of 2011 and was Canada’s only operating primary silver mine from 2011 to 2013. The opening of Bellekeno marked the rebirth and rejuvenation of one of Canada’s most famous and prolific historic mining districts.
Following suspension of operations at Bellekeno in 2013 and subsequent discovery of two new high-grade silver deposits, Alexco published the Keno Hill PFS. The PFS anticipates sequential production from four high-grade silver deposits (Bermingham, Flame & Moth, Bellekeno and Lucky Queen) over an eight-year mine life, producing 1.18 Mt of ore with an average silver grade of 805 g/t, 2.98% lead and 4.13% zinc. Silver production is anticipated to be approximately 4 Moz per year. All deposits are characterized by high-grades and variable vein widths and will be mined by mechanized underground mining methods of MCF and LH with cemented rock fill and unconsolidated rock fill.
In June 2020 Alexco received the final permits and made a positive decision to move forward to renew silver production at Keno Hill. The Company expects to begin concentrate production and sales in Q4 2020.
Keno Hill PFS(1) Highlights
|Mine life||8 years|
|Mine plan||1.18 Mt at average 805 g/t silver|
|Mining operation||Underground mining – cut and fill/longhole|
|Annual Ag production||~4 Moz silver per year|
|Processing rate||400 tpd; increasing to 550 tpd in year 3/4|
|All-in Sustaining Costs2||~US$11.94/oz Ag (net of by-product credits)|
|Pre-production Capex||$17.9 M|
|Working Capital||$5.3 M|
|Average LOM net smelter return||$554/tonne of ore|
|Direct operating costs||$321/tonne of ore|
|After tax NPV||$101.3 M|
|After Tax IRR||74%|
1 Refer to news release dated March 28, 2019 entitled “Alexco Announces Positive Pre-Feasibility Study for Expanded Silver Production at Keno Hill Silver District
2 AISC is a non-GAAP measure calculated on a produced (contained) basis net of by-products, as defined by the World Gold Council. Calculated using the following Average Prices: Ag US$ 17.91/oz, Au US$ 1,325/oz, Pb US$ 1.00/lb, Zn US$ 1.22/lb. and US$/CDN$ FX of $0.76.