Overview
| Stage | Preliminary Economic Assessment |
| Mine Type | Open Pit |
| Commodities |
|
| Mining Method |
|
| Mine Life | 7 years (as of Jan 1, 2020) |
Source:
The Property comprises 3,315 contiguous quartz mineral claims that are 100% owned by ATAC, totaling 665.9 km2 (66,590 ha).
On July 11, 2023, Hecla Mining Company (NYSE:HL) (the “Company”) announced, that the Company, through its wholly-owned subsidiary Alexco Resource Corporation (“Alexco”), has completed the acquisition of all the issued and outstanding shares of ATAC Resources Ltd. (“ATAC”) and it has also invested CAD$2 million in seed capital, equal to 19.9% interest, for a new exploration company Cascadia Minerals Ltd. (“Cascadia”), which was spun-out to ATAC’s shareholders as part of the transaction (the “Arrangement”).
ATAC is now a wholly-owned indirect subsidiary of Hecla.
Contractors
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Deposit Type
- Sediment-hosted
- Carbonate replacement
- Vein / narrow vein
Summary:
Several types of mineralization are known to occur on the Property including:
1. sediment-hosted replacement-style gold
2. zinc ± silver ± lead ± gold ± bismuth in limonite-rich veins and replacement bodies
3. scheelite in tremolite skarns
4. pyrrhotite ± scheelite ± chalcopyrite in actinolite-diopside ± garnet skarns
5. wolframite ± tantalite in granite
6. gold bearing quartz-boulangerite veins
7. pyrite-sphalerite-galena in carbonate replacement deposits.
Sediment-hosted replacement style gold mineralization is the most significant economic mineralization explored on the Property to date. Known showings of this type include the Tiger Deposit.
The Tiger Deposit is located 3 km west-northwest of the Rackla Pluton in a moderate to steep walled valley. It consists of a thick northwesterly trending body of carbonate replacement style gold mineralization hosted by a variably northeast dipping horizon. It has been delineated for about 900m along strike and about 400m in dip extent. The mineralization occurs in multiple zones over an aggregate thickness of up to about 150m. Mineralization is developed within and adjacent to a regionally extensive corridor of highly strained rocks that are manifested as a 40 to 150 m wide zone of small-scale folding and shearing. The geometry of the mineralized system is defined by a series of stacked and folded carbonate horizons intercalated with locally extensive mafic flows and volcanicla ........
Summary:
The open pit mine will utilize a conventional truck-and-excavator fleet. Based on the geotechnical recommendations provided by Golder(2016),blasting will be performed on non-oxide rock only, while oxide material will be excavated directlyby a hydraulic excavator.
Pit optimization and production scheduling were completed using the Measured, Indicated and Inferred Oxide and SulphideMineral Resources. The Project’s LOM is approximately seven years, including one year of pre-stripping followed by six years of mill production. Over the seven-year LOM, the pit will produce 2.7 Mt of mineralized material and 14.4 Mt of waste rock. The overall LOM average gold grade of oxide and sulphide material is 3.82 g/t. The LOM stripping ratio (defined as waste material mined divided by mineralized material mined) is 5.3.
Mining operations will be performed using leased mining equipment. Small mining equipment with operating flexibility was selected to match the pit production schedule and the nature of site. The equipment selection, sizing, and fleet requirements were based on anticipated site operating conditions, haulage profiles, cycle times, and overall equipment utilization. In determining the number of units for major equipment such as drills, excavators, and trucks, annual operating hours were calculated and compared to the available hours for the equipment. Mine support equipment, such as track dozers, motor graders, water/sanding trucks, etc., was matched with t ........
Source:
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Flow Sheet:
Summary:
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Projected Production:
| Commodity | Units | Avg. Annual | LOM |
|
Gold
|
koz
| 44 | 267 |
All production numbers are expressed as metal in doré.
Operational Metrics:
| Metrics | |
|
Daily processing capacity
| 1,500 t * |
|
Annual processing capacity
| 547,500 t * |
|
Stripping / waste ratio
| 5.3 * |
|
Waste tonnes, LOM
| 14,378 kt * |
|
Ore tonnes mined, LOM
| 2,711 kt * |
|
Total tonnes mined, LOM
| 17,088 kt * |
|
Tonnes processed, LOM
| 2,711 kt * |
* According to 2020 study.
Reserves at January 3, 2020:
Mineral Resources are reported at a 0.75g Au/t cut-off for open pit material and a 1.5g Au/t cut-off in underground material.
| Category | Tonnage | Commodity | Grade | Contained Metal |
|
Measured & Indicated
|
4,526,000 t
|
Gold
|
3.19 g/t
|
464 koz
|
|
Measured & Indicated
|
4,526,000 t
|
Tungsten
|
221 ppm
|
1,000 t
|
|
Inferred
|
165,000 t
|
Gold
|
2.17 g/t
|
11.5 koz
|
|
Inferred
|
165,000 t
|
Tungsten
|
109 ppm
|
18 t
|
Corporate Filings & Presentations:
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