Hecla’s 100% owned Casa Berardi mine, is an underground gold mine located in western Quebec, a politically stable and mining friendly region, with good geology and infrastructure. In 2019, the mine produced 134,409 ounces of gold at a cash cost, after by-product credits, per gold ounce of $1,051 (1). The mill throughput rate averaged 3,775 tons per day. The mine is expected to produce 135,000 to 140,000 ounces of gold in 2020 at a cash cost, after by-product credits, of $875 – $900 per ounce (1).
(1) Cash cost, after by-product credits, per gold ounce represents a non-GAAP measurement, a reconciliation of which to cost of sales and other direct production costs and depreciation, depletion and amortization (GAAP) can be found in the legal page of this website.
The Casa Berardi mine is situated 95 kilometres north of La Sarre, Quebec and straddles a 37 kilometre section of the Casa Berardi fault.
The Casa Berardi gold deposits are located along a five kilometre east-west mineralized corridor. They include the East and West mines, and the Principal Zones. The Casa Berardi gold deposits can be classified as an Archean sedimentary-hosted lode gold deposit. The gold mineralization is superimposed on a continuous graphitic mudrock unit corresponding to the Casa Berardi Fault plane. Gold occurs mainly south of the Casa Berardi Fault, and occasionally on both sides of the fault.
The West Mine shaft deepening project, which included construction of loading pockets and other related infrastructure, was completed in the fourth quarter of 2014, and is improving mine operations by providing additional access to the 118 and 123 zones for transporting ore and waste from underground. Excavation of the 985 drift (previously referred to as 1010) from the deepened shaft is underway. This drift is expected to improve ventilation and material handling and also provide a platform for deeper exploration drilling.
The Company is now producing ore from the East Mine Crown Pillar (EMCP) pit. Located near the East mine, the capital for this shallow pit project is expected to be $39 million over 5.5 years. The project has an expected IRR of 90%, contributed 27,588 ounces in 2019, and is expected to produce about 30,000 ounces of gold until the end of the project.
Casa Berardi is an underground trackless mine accessed by declines and a shaft, which produced approximately 2,100 tonnes of ore per day in 2015. The mining methods are longhole transversal stoping in 10 metres or more mineralization width, and longitudinal retreat stoping in narrower ore bodies. The mineralized zones put in reserves are of varying thickness, ranging from a few tens of meters to 3 meters, which is the minimum mining width. Most of the hanging walls are sub-vertical (55° to 85°), with typically the graphitic Casa Berardi fault at the footwall.
The mine has produced approximately 1.9 million recovered gold ounces since commencing production in 1988, including about 931,244 recovered ounces since production recommenced in November 2006.
|(years ended December 31)|
|Cash cost per ounce of gold, after by-product credits, ($/oz) (1)||$772.00||$764.00||$820.00||$800.00||$1,051.00|
- (footnotes)(1) Cash cost, after by-product credits, per silver or gold ounce is a non-GAAP measurement. A reconciliation of cash cost, after by-product credits, per silver or gold ounce to cost of sales and other direct production costs and depreciation, depletion and amortization (GAAP) can be found in the legal page of this website.
Information with respect to proven and probable ore reserves, measured, and inferred resources is set forth below.
|(As of December 31, 2019 unless otherwise noted)|
|(000)||(oz/ton)||(oz/ton)||(%)||(%)||(000 oz)||(000 oz)||(Tons)||(Tons)|
|Open Pit -|
|Proven Reserves (1,2)||5,873||–||0.08||–||–||–||447||–||–|
|Probable Reserves (1,2)||11,802||–||0.07||–||–||–||809||–||–|
|Proven and Probable Reserves (1,2)||17,675||–||0.07||–||–||–||1,257||–||–|
|Proven Reserves (1,2)||974||-||0.16||-||-||-||256||-||-|
|Probable Reserves (1,2)||1,978||-||0.15||-||-||-||305||-||-|
|Proven and Probable Reserves (1,2)||2,952||-||0.15||-||-||-||461||-||-|
|Open Pit -|
|Measured Resources (3)||193||–||0.02||–||–||–||4||–||–|
|Indicated Resources (3)||3,341||–||0.05||–||–||–||155||–||–|
|M&I Resources (3)||3,534||–||0.04||–||–||–||158||–||–|
|Measured Resources (3)||1,841||-||0.15||-||-||-||273||-||-|
|Indicated Resources (3)||4,463||-||0.14||-||-||-||631||-||-|
|M&I Resources (3)||6,304||-||0.14||-||-||-||904||-||-|
|Open Pit -|
|Inferred Resources (3)||11,724||–||0.04||–||–||–||498||–||–|
|Inferred Resources (3)||2,485||-||0.19||-||-||-||471||-||-|
- (footnotes)Note: All estimates are in-situ. Resources are exclusive of reserves. Totals may not represent the sum of parts due to rounding.
(1) The term “reserve” means that part of a mineral deposit that can be economically and legally extracted or produced at the time of the reserve determination. The term “economically,” as used in the definition of reserve, means that profitable extraction or production has been established or analytically demonstrated to be viable and justifiable under reasonable investment and market assumptions. The term “legally,” as used in the definition of reserve, does not imply that all permits needed for mining and processing have been obtained or that other legal issues have been completely resolved. However, for a reserve to exist, Hecla must have a justifiable expectation, based on applicable laws and regulations, that issuance of permits or resolution of legal issues necessary for mining and processing at a particular deposit will be accomplished in the ordinary course and in a timeframe consistent with Hecla’s current mine plans.
(2) Mineral reserves are based on $1300 gold and a US$/CAN$ exchange rate of 1:1.35 Reserve diluted to an average of 34.7% to minimum width of 9.8 feet (3 m). The average cut-off grades at Casa Berardi are 0.105 oz/ton gold (3.49 g/tonne) for underground mineral reserves and 0.025 oz/ton gold (0.85 g/tonne) for open pit mineral reserves.
(3) Measured, indicated and inferred resources are based on $1,500 gold and a US$/CAN$ exchange rate of 1:1.35 Underground resources are reported at a minimum mining width of 6.6 to 9.8 feet (2 m to 3 m). The average cut-off grades at Casa Berardi are 0.105 oz/ton gold (3.49 g/tonne) for underground mineral resources and 0.025 oz/ton gold (0.85 g/tonne) for open pit mineral resources.
Reporting requirements in the United States for disclosure of mineral properties are governed by the SEC and included in the SEC’s Securities Act Industry Guide 7, entitled “Description of Property by Issuers Engaged or to be Engaged in Significant Mining Operations” (Guide 7). However, the Company is also a “reporting issuer” under Canadian securities laws, which require estimates of mineral resources and reserves to be prepared in accordance with Canadian National Instrument 43-101 (NI 43-101). NI 43-101 requires all disclosure of estimates of potential mineral resources and reserves to be disclosed in accordance with its requirements. Such Canadian information is being included here to satisfy the Company’s “public disclosure” obligations under Regulation FD of the SEC and to provide U.S. holders with ready access to information publicly available in Canada.
Reporting requirements in the United States for disclosure of mineral properties under Guide 7 and the requirements in Canada under NI 43-101 standards are substantially different. This website contains a summary of certain estimates of the Company, not only of proven and probable reserves within the meaning of Guide 7, which requires the preparation of a “final” or “bankable” feasibility study demonstrating the economic feasibility of mining and processing the mineralization using the three-year historical average price for any reserve or cash flow analysis to designate reserves and that the primary environmental analysis or report be filed with the appropriate governmental authority, but also of mineral resource and mineral reserve estimates estimated in accordance with the definitional standards of the Canadian Institute of Mining, Metallurgy and Petroleum referred to in NI 43-101. The terms “measured resources”, “indicated resources,” and “inferred resources” are Canadian mining terms as defined in accordance with NI 43-101. These terms are not defined under Guide 7 and are not normally permitted to be used in reports and registration statements filed with the SEC in the United States, except where required to be disclosed by foreign law. The term “resource” does not equate to the term “reserve”. Under Guide 7, the material described herein as “indicated resources” and “measured resources” would be characterized as “mineralized material” and is permitted to be disclosed in tonnage and grade only, not ounces. The category of “inferred resources” is not recognized by Guide 7. Investors are cautioned not to assume that any part or all of the mineral deposits in such categories will ever be converted into proven or probable reserves. “Resources” have a great amount of uncertainty as to their existence, and great uncertainty as to their economic and legal feasibility. It cannot be assumed that all or any part of such a “resource” will ever be upgraded to a higher category or will ever be economically extracted. Investors are cautioned not to assume that all or any part of a “resource” exists or is economically or legally mineable. Investors are also especially cautioned that the mere fact that such resources may be referred to in ounces of silver and/or gold, rather than in tons of mineralization and grades of silver and/or gold estimated per ton, is not an indication that such material will ever result in mined ore which is processed into commercial silver or gold.
At Casa Berardi, the 1,378,065 tons processed at the mill contained approximately 165,368 ounces of gold, with 57% of the milled tonnage coming from underground and 43% of the milled tonnage coming from the East Mine Crown Pillar (EMCP) Pit. Proven and probable gold reserves decreased approximately 10% to 1.72 million ounces and reserve tonnage at Casa Berardi decreased 4% to 20.6 million tons over 2018. There was an overall reduction in underground reserves of 105,600 gold ounces and a decrease of open pit reserves of 83,100 gold ounces compared to 2018. Most of these decreases were due to mining depletion. Hecla has mined over 1 million ounces of gold at Casa Berardi since acquisition in 2013.
Measured and indicated gold resources decreased 12% from 2018 levels as gains from underground drilling were offset by decreases in the Pit areas. The largest decreases were a result of conversion to underground reserves of the 148 Zone and reclassification of some resources to Inferred below the 160 Pit. Inferred gold resources increased 49% from 2018 levels.
During the fourth quarter of 2019, up to seven underground drills were used to refine stope designs, expand reserves and resources in the 113, 118, 119, 124, 128 and 148 zones and confirm further potential at depth and to the east and west. One drill on surface completed in-fill and exploration drilling within and near the proposed 160 Pit (Figure 5) and continues to confirm continuity with the pit outline and expand resource outside of the current pit design.
Drilling in the East Mine focused on defining continuity and expanding mineralization in the high-grade 148 Zone and open pit mineralization within and outside the proposed 160 Pit. Within the 148-01 lens in the 148 Zone, high-grade intersections include 0.48 oz/ton gold over 11.8 feet, 0.89 oz/ton gold over 14.8 feet and 0.47 oz/ton gold over 29.8 feet confirming continuity within the lens. Drilling in the 160 Zone within and below the current pit outline continues to define broad intervals of mineralization and adding resources with recent intersections including 0.11 oz/ton gold over 113.2 feet and 0.13 oz/ton gold over 68.6 feet.
In the West Mine area, drilling in the 113 and 118 zones targeted multiple lenses along the Casa Berardi Fault in order to extend known mineralization at depth and to the east outside of the current resources. Recent intersections including 0.11 oz/ton gold over 26.2 feet suggest this zone continues to be open at depth. High in the mine, drilling targeted the eastern extension of the stacked 119 Zone ore lenses at the contact between the sediments and volcanics associated with pyritic chert and stacked quartz veins south of the Casa Berardi Fault. Recent intersections include 0.25 oz/ton gold over 29.5 feet including 0.42 oz/ton gold over 5.9 feet and 0.12 oz/ton gold over 37.1 feet.
In the first quarter of 2020, underground drilling is expected to expand and refine resources in 123 Zone in the West Mine and the high-grade 148 Zone in the East Mine. Underground exploration drilling during the year is planned to evaluate the lower extension of the 113-118 and 128 zones in the West Mine and the 146, 148, and 152 zones in the East Mine.
The Company began producing gold from the first surface pit in 2016. Once the EMCP is exhausted, it is expected that the Principal pit will begin operating to maintain the 2,900 tonnes per day throughput.
125 Years of Mining (French)