The mining newspaper for Alaska and Canada's North
The mining newspaper for Alaska and Canada's North
North of 60 Mining News - February 14, 2023
This core from 2018 drilling shows the very high-grade silver mineralization often encountered at Hecla's Keno Hill project.
Map showing the location of the underground drilling completed at the Greens Creek silver mine in Alaska during the fourth quarter of 2022.
Map showing the three silver exploration targets drilled last year in relation to the Bermingham and Flame and Moth deposits within Hecla's newly acquired Keno Hill property in Canada's Yukon.
With the addition of the Keno Hill Mine in the Yukon, Hecla Mining Company now has more than 240 million ounces of silver in reserves, the highest in the company's 131-year history.
"Hecla's silver reserves are an all-time high," said Hecla Mining CEO Phillips Baker, Jr.
For more than a decade, it has become customary for Hecla's exploration team to find enough new ore at its operations to more than replace the reserves that have been mined each year, resulting in annual growth of silver reserves.
"In the past 15 years, we have replaced the 213 million ounces mined and yet have almost five times the reserves we had at the start of 2008," the Hecla CEO added. "That is over 400 million ounces of silver that we have replaced and grown."
While silver reserves at its Greens Creek and Lucky Shot mines in the United States are down slightly from last year, the 2022 buyout of Alexco Resource Corp. and that company's Keno Hill Mine project in Canada more than made up for the deficit by adding roughly 50 million oz of silver to Hecla reserves.
As a result, the Idaho-based mining company now has 240.9 million oz of silver, 2.56 million oz of gold, 944,020 tons of zinc, and 784,940 tons of lead in 36.83 million tons of reserves at its four operations in the U.S. and Canada.
"Hecla has the largest silver reserve in the United States, the highest grade and largest primary silver reserve in Canada, the best silver exploration potential in both countries, and we produce 40% of all the silver mined in the United States and expect to produce the same percentage of Canada's production next year," said Baker. "With silver's importance in the energy transition to renewables, Hecla is well positioned long into the future," Baker said.
With the September closing of its acquisition of Alexco, Hecla gained full ownership of the Keno Hill Silver District property in the Yukon.
Going into 2023, Keno Hill hosts 2.2 million tons of proven and probable reserves averaging 22.5 oz/t (49.7 million oz) silver, 0.01 oz/t (13,000 oz) gold, 2.2% (49,320 tons) zinc, and 2.4% (52,520 tons) lead.
This is a 33% increase over the reserves identified at the time of Hecla's acquisition of Alexco.
The increase is due primarily to infill drilling of Deep Northeast, a particularly high-grade zone of the Bermingham deposit that is expected to be part of the mine plan when Hecla resumes commercial operations at Keno later this year.
In addition to reserves, Keno Hill hosts 4.06 million tons of indicated resource averaging 8 oz/t (32.3 million oz) silver, 0.007 oz/t (29,000 oz) gold, 4% (160,130 tons) zinc, and 1% (39,540 tons) lead; plus 2.44 million tons of inferred resources averaging 10.4 oz/t (25.5 million oz) silver, 0.003 oz/t (8,000 oz) gold, 2.1% (51,000 tons) zinc, and 0.9% (22,380 tons) lead.
During the fourth quarter, Hecla had two surface drills confirming high-grade silver mineralization at three targets along the trend that hosts the reserves at Keno Hill – Silver King, Coral-Wigwam, and Hector-Calumet. (See map below for Keno Hill exploration target locations.)
Highlights from this drilling include:
• 3.6 meters averaging 19.6 oz/t silver, 0.2% zinc, and 0.9% lead in hole K-22-0810 (Silver King).
• 2.2 meters averaging 101 oz/t silver, 0.1% zinc, 0.1% lead, and 0.3% copper in hole K-22-0825 (Coral Wigwam).
• 7.5 meters averaging 5 oz/t silver, 0.5% zinc, and 1.1% lead in hole K-22-0829 (Hector Calumet).
• 3.4 meters averaging 10.5 oz/t silver, 4% zinc, and 1.1% lead in hole K-22-0837 (Hector Calumet).
"Keno Hill's 2022 exploration results are particularly remarkable with only three targets drilled that all resulted in three meaningful, high-grade discoveries," said Baker. "This reflects the quality of the land position and the knowledge of the long-standing team who have taken their experience at Bermingham and applied it to the new targets. These initial results exceed our already high expectations for the exploration potential of the district."
The 2023 drill program at Keno Hill is slated to include underground definition drilling of the Bear zone at Bermingham and the Lightening zone at the Flame & Moth deposit, along with surface exploration of the high-grade veins in the Hector-Calumet, Coral-Wigwam and Silver King target areas, as well as zones below Bermingham Northeast and untested zones above Bermingham Deep Northeast.
For the first time in several years, drilling did not replace the reserves mined at the Greens Creek Mine in Southeast Alaska during 2022.
Going into 2023, Greens Creek hosted 10.68 million tons of proven and probable reserves averaging 10.9 oz/t (116.9 million oz) silver, 0.09 oz/t (935,000 oz) gold, 6.5% (695,160 tons) zinc, and 2.5% (264,750 tons) lead.
This marks a 7% drop in silver reserves compared to the reserves going into 2022. Hecla attributes much of this drop to the removal of lower-margin material and material adjacent to historically mined areas with unknown backfill conditions.
While reserves dropped at Greens Creek, the company reports a slight increase in resources.
Exclusive of reserves, Greens Creek hosts 8.4 million tons of indicated resource averaging 12.9 oz/t (108.7 million oz) silver, 0.1% (810,000 oz) of gold, 8% (675,740 tons) zinc, and 2.9% (245,990 tons) lead; plus 2.8 million tons of inferred resource averaging 12.1 oz/t (28.9 million oz) silver, 0.07 oz/t (178,000 oz) gold, 6.9% (164,080 tons) zinc, and 2.8% (67,400 tons) lead.
During the fourth quarter, four underground rigs at Greens Creek carried out resource conversion drilling in the 200 South, East, Gallagher, and West ore zones as well as exploration on the southern extension of the West and Gallagher Fault Block zones.
Assay results were received for the Southwest Bench, 200 South, East, West, and Upper Plate areas, and results continue to confirm and expand mineral zones but were not yet included in the reserve calculation.
Hecla also carried out helicopter-supported surface drilling at the Upper Plate Zone and targets northwest of the area currently being mined at Greens Creek.
The 2023 underground drill program at Greens Creek will include underground definition drilling at seven zones, underground exploration, and surface exploration in the immediate mining area and at Lil'Sore.
The 2022 drill program replaced the silver reserves mined last year at Hecla's iconic Lucky Friday Mine in Idaho.
Going into 2023, Lucky Friday hosted 5.57 million tons of proven and probable reserves averaging 13.4 oz/t (74.6 million oz) silver, 3.6% (199,530 tons) zinc, and 8.4% (467,670 tons) lead.
While reserves held steady, the resources dropped.
Exclusive of reserves, Lucky Friday entered 2023 with 7.43 million tons of measured and indicated resources averaging 7.8 oz/t (58,132 oz) silver, 2.5% (187,200 tons) zinc, and 5.4% (400,240 tons) lead; plus 3.59 tons of inferred resource averaging 8.7 oz/t (31.3 million oz) silver, 2.4% (84,700 tons) zinc, and 6.3% (224,670 tons) lead.
This marks a roughly 27% decrease in silver reporting to the measured and indicated categories and 25% drop in silver reporting to the inferred category compared to the resources going into 2022.
Hecla attributes the fall in measured and indicated resources are due to upgrading roughly 49 million oz of silver to reserves, along with increased cut-off grades removing some material.
The decrease in inferred resource is due primarily to increased cut-off grades along the edges of the resources and at the higher elevations of the 30 Vein, along with some inferred resources on the 30 Vein being upgraded to higher resource and reserve categories.
Hecla did not report any results from fourth-quarter drilling at Lucky Friday or plans to carry out any exploration or resource definition programs at the Idaho mine during 2023.
At the Casa Berardi Mine in Quebec, Hecla's only primary gold operation, reserves dropped by 10% last year.
Going into 2023, Casa Berardi hosted 16.84 million tons of open pit mineable proven and probable reserves averaging 0.08 oz/t (1.35 million oz) gold, plus 1.54 million tons of underground proven and probable reserves averaging 0.17 oz/t (261,000 oz) gold.
Hecla attributes the drop in reserves primarily to increased costs and cut-off grades.
While reserves dropped, all resource categories increased at the Quebec mine.
Exclusive of reserves, Casa Berardi went into 2023 with 1.81 million tons of open pit mineable measured and indicated resources averaging 0.04 oz/t (67,000 oz) gold; 6.31 million tons of underground measured and indicated resources averaging 0.19 oz/t (1.19 million oz) gold; 7.83 million tons of open pit inferred resource averaging 0.05 oz/t (389,000 oz) gold; and 2.44 million tons of underground inferred resource averaging 0.19 oz/t (430,000 oz) gold.
This marks a 19% increase in gold reporting to measured and indicated resource and a 4% rise in gold in the inferred resource category.
The sharp rise in measured and indicated resources is primarily due to a downgrade of some reserves, and the bump in inferred resource is from exploration drilling.
At Casa Berardi, up to six underground core drills and two surface core drills were focused on definition and exploration drilling in multiple zones and targets in the West Mine, Principal Mine, and East Mine areas.
Hecla plans to carry out additional underground definition drilling, along with exploration drilling focused on high-grade extensions of several zones at Casa Berardi.
Regional surface exploration will test anomalies identified during previous sonic drilling in the east and west blocks of the Quebec mine.
Over his more than 16 years of covering mining and mineral exploration, Shane has become renowned for his ability to report on the sector in a way that is technically sound enough to inform industry insiders while being easy to understand by a wider audience.
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