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 2018, the mine produced 130,647 ounces of gold at a cash cost, after by-product credits, per gold ounce of $800 (1). The mill throughput rate averaged 3,769 tons per day. The mine is expected to produce 150,000 ounces of gold in 2019 at a cash cost, after by-product credits, of $850 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 $39 million over 5.5 years. The project has an expected IRR of 90%, contributed 32,097 ounces in 2018, and is expected to produce about 30,000 ounces of gold until the end of the project.
Casa Berardi is an underground trackless mine accessed by declines and a shaft, which produced approximately 2,100 tonnes of ore per day in 2015. The mining methods are longhole transversal stoping in 10 metres or more mineralization width, and longitudinal retreat stoping in narrower ore bodies. The mineralized zones put in reserves are of varying thickness, ranging from a few tens of meters to 3 meters, which is the minimum mining width. Most of the hanging walls are sub-vertical (55° to 85°), with typically the graphitic Casa Berardi fault at the footwall.
The mine has produced approximately 1.9 million recovered gold ounces since commencing production in 1988, including about 931,244 recovered ounces since production recommenced in November 2006.
|(years ended December 31)|
|Cash cost per ounce of gold, after by-product credits, ($/oz) (1)||$826.35||$772.00||$764.00||$820.00||$800.00|
- (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, 2018 unless otherwise noted)|
|(000)||(oz/ton)||(oz/ton)||(%)||(%)||(000 oz)||(000 oz)||(Tons)||(Tons)|
|Proven Reserves (1,2)||6,790||–||0.08||–||–||–||563||–||–|
|Probable Reserves (1,2)||16,954||–||0.08||–||–||–||1,343||–||–|
|Proven and Probable Reserves (1,2)||23,743||–||0.08||–||–||–||1,907||–||–|
|Measured Resources (3)||1,952||–||0.15||–||–||–||299||–||–|
|Indicated Resources (3)||10,797||–||0.08||–||–||–||906||–||–|
|M&I Resources (3)||12,749||–||0.09||–||–||–||1,205||–||–|
|Inferred Resources (3)||6,222||–||0.10||–||–||–||652||–||–|
- (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 $1,200 gold and a US$/CAN$ exchange rate of 1:1.33. Reserve diluted to an average of 34.7% to minimum width of 9.8 feet (3 m).
Reserves at Casa Berardi were determined by Jonathan Archambault-Giroux, P. Geo., Que., Real Parent, P.Geo. Que., Sylvain Picard, P. Eng., Que. and Alain Quenneville, P. Eng., Que. unless otherwise stated.
Open pit mineral reserves of the Principal Mine were estimated in September 2018 by Hecla Quebec and Mine Development Associates based on $1225 gold and a US$/CAN$ exchange rate of 1:3.
Hecla Mining Company, Principal Deposit Open Pit Mining Study – 2018
September 1, 2018, by Mine Development Associates, Thomas L. Dyer, P.E.
Open pit mineral reserves of the 160 and 134 Zones were estimated in January 2018 by Hecla Quebec and Mine Development Associates based on $1225 gold and a US$/CAN$ exchange rate of 1.3.
Hecla Mining, Casa Berardi 160 and 134 Zones, Open Pit Mining Study – 2017
January 12, 2018, by Mine Development Associates, Thomas L. Dyer, P.E.
Open pit mineral reserves of the West Mine Crown Pillar were estimated in January 2019 by Hecla Quebec and Mine Development Associates based on $1225 gold and a US$/CAN$ exchange rate of 1.3.
Hecla Mining Company, West Mine Crown Pillar Deposit, Open Pit Mining Study – 2018
January 10, 2019, by Mine Development Associates, Thomas L. Dyer, P.E.
Open pit mineral reserves of the East Mine Crown Pillar Expansion were estimated in August 2018 by Hecla Quebec and Mine Development Associates based on $1225 gold and a US$/CAN$ exchange rate of 1.3.
Hecla Mining Company, East Mine Crown Pillar Expansion, Open Pit Mining Study – 2018
August 22, 2018, by Mine Development Associates, Thomas L. Dyer, P.E.
(3) Measured, indicated and inferred resources are based on $1,350 gold and a US$/CAN$ exchange rate of 1:1.33 Underground resources are reported at a minimum mining width of 6.6 to 9.8 feet (2 m to 3 m).
Resources at Casa Berardi were determined by Jonathan Archambault-Giroux, P. Geo., Que., Real Parent, P.Geo. Que., and Alain Quenneville, P. Eng., Que. unless otherwise stated.
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 in 2018, the 1,375,718 tons processed at the mill contained approximately 162,744 ounces of gold, with 744,952 tons (54%) of the milled tonnage coming from underground and 630,776 tons (46%) of the milled tonnage coming from the East Mine Crown Pillar (EMCP) open pit. Gold reserves increased approximately 28% to 1.91 million ounces and reserve tonnage at Casa Berardi increased 71% to 23.7 million tons over 2017. Depletion decreased underground reserve ounces in the 104 (Lower Inter), 113, 118, 123 and 124 zones. This was offset by reserve additions in the west extension of the EMCP as well as 134 and 160 pits. Substantial reserve increases occurred in the proposed West Mine Crown Pillar (WMCP) and Principal pits where some underground reserves were incorporated into an expanded pit. There was an overall reduction in underground reserves of 176,400 gold ounces and an increase of open pit reserves of 589,600 gold ounces compared to 2017.
Measured and indicated gold resources decreased 12% from 2017 levels as gains from underground drilling of the 119 and 123 zones and 134 and 160 open pits were offset by decreases at the 107 (South West), 108 (Inter), 111, 113, 115, 117, 118, 121, 124, and 160 underground. The largest decreases were a result of incorporation of the 107 (South West) and 160 underground to open pit reserves. Inferred gold resources decreased 9% from 2017 levels as increases at the 105, 116, 124, 134, 146, 157, and 160 (underground and open pit) zones were offset by losses to inferred resources in the 107 (South West) 108 (Inter) 118, 119, 121, 123, 148, and 160 underground and open pit zones by conversion to indicated resources. Significant losses to inferred resources in the 107 and 108 zones were due to resource upgrades and incorporation into the new WMCP pit. A new NI-43-101 Technical Report is expected in the second quarter of 2019.
During the fourth quarter of 2018, up to six underground drills were used to refine stope designs, expand reserves and resources in the 118, 121, 123, 124, 125, and 128 zones and confirm further potential at depth and to the east and west. Up to four drills on surface completed in-fill and exploration drilling at the West Mine Crown Pillar (WMCP), the 128-129 zones east of the Principal pit and near the proposed 160 pit. The WMCP pit represents the latest in a series of existing and proposed open pits along the Casa Berardi Fault or Deformation Zone.
At the Lower 118 Zone, drilling confirmed the continuity of multiple mineralized lenses to the west and at depth outside the current resource boundary. Recent intersections continue to expand this resource, including 0.63 oz/ton gold over 13.1 feet and 2.69 oz/ton gold over 2.6 feet. This drilling suggests the zone is open at depth below the 1200-level and to the west. Near the top of the 123 Zone, step-out drilling to the east show the continuity of high-grade mineralization down plunge for 400 feet from surface. Drilling from the 710-790 levels have extended gold mineralization at depth and further to the west with intersections of 0.39 oz/ton gold over 10.8 feet and 0.35 oz/ton gold over 8.9 feet. Drilling from the 970 level, at the bottom of the mine, confirmed multiple lenses and suggests these mineralized lenses plunge east at depth and remain open for exploration.
High in the mine, drilling has targeted the east extension of the 124 Zone that is down-plunge of the Principal pit mineralization. Drilling below the 290-level continues to show the down-dip potential of the 124 lenses to depth. Further east, drilling of the 128-129 zones is defining a high-grade, steeply-plunging series of lenses that have been defined vertically for 600 feet and may extend below the 290 level. Recent drill intersections include 0.35 oz/ton gold over 10.2 feet and 1.25 oz/ton gold over 1.6 feet.
Definition drilling has commenced at the 300-level of the East Mine to refine the depth extensions of the 160 Zone below the pit shells. Drilling has defined broad intervals of mineralization including 0.21 oz/ton gold over 20.3 feet and 0.16 oz/ton gold over 19.9 feet. This mineralization is steeply plunging to the west and is open to depth. Drilling of the WMCP to evaluate open pit potential west of the West Shaft has upgraded the current inferred resource to reserves that are part of a newly defined open pit reserve. The recent results below show that the near-surface, mineralized structures extends both beyond the western extent of the WMCP pit.
In the first quarter of 2019, underground drilling is expected to expand and refine the 118 and 123 zones lower in the mine and the 124-128 zones closer to surface. Underground exploration drilling is planned to evaluate the lower extension of the 113 Zone and the 128 Zone. Surface drilling programs are planned at the western extension of the WMCP and the 128-129 zones to define and expand underground mining potential east of the Principal area along the Casa Berardi Fault.
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)