お知らせ • Jul 09
Sandfire Resources America Inc. Delivers Black Butte Copper Project Preliminary Feasibility Study Update with New Lowry Reserves and Enhanced Production Profile
Sandfire Resources America Inc. announced the results of an updated Preliminary Feasibility Study (PFS) for the Black Butte Copper Project that significantly enhances the Project’s long-term value through the inclusion of the nearby Lowry copper deposit in the mine plan. The updated PFS positions the Black Butte Copper Project as one of the highest-grade undeveloped underground copper projects in the United States. The Project is forecasted to generate USD 3,300 million in gross revenue and USD 1,300 million in pre-tax net cashflow during mine operations based on a copper price of USD 4.70/lb. The Project has a pre-tax NPV8% of USD 213 million (IRR 15.6%) and a post-tax NPV8% of USD 126 million (IRR 13.3%). At a copper price of USD 6.00/lb, pre-tax NPV8% increases to USD 707 million (IRR 30.4%) and post-tax NPV8% increases to USD 516 million (IRR 26.3%). The addition of the high-grade Lowry Deposit to the existing Johnny Lee Deposit is expected to lower unit operating costs by USD 2.28/tonne, extend mine life by four years through the use of a more cost-effective mechanized long-hole stoping mining method, and realize operational efficiencies through concurrent mining practices. The Project is forecasted to deliver post-tax cashflow of USD 476 million, an increase of USD 122 million over the life of mine. The Project underpins an improved 12-year mine life and is designed to produce 1,445,000 dry metric tonnes of copper concentrate containing 370,000 tonnes of copper metal over the mine lifespan. Average annual production is approximately 31,000 tonnes of contained copper metal at a direct operating cash cost of USD 2.68/lb. For the Johnny Lee Deposit, the Measured and Indicated Mineral Resource of 18.9 million tonnes at 2.4% copper for 462,000 tonnes of contained copper and Inferred Mineral Resource of 3.4 million tonnes at 1.9% copper for 64,000 tonnes of contained copper are maintained. Using a Net Smelter Return cut-off value of USD 110/t, Probable Mineral Reserves are reported at 9.5 million tonnes grading 2.9% copper for 270,000 tonnes of contained copper. For the Lowry Deposit, located approximately 3 km south-east of Johnny Lee, a Measured and Indicated Mineral Resource of 17.9 million tonnes at 1.4% copper for 248,000 tonnes of contained copper and an Inferred Mineral Resource of 13.7 million tonnes at 1.1% copper for 151,000 tonnes of contained copper have been defined. Probable Mineral Reserves are reported at 4.7 million tonnes grading 2.1% copper for 100,000 tonnes of contained copper. Development of the Lowry Deposit remains subject to permitting and regulatory approvals. The revised PFS confirms a significant milestone, increasing combined Probable Mineral Reserves to 14.3 million tonnes grading 2.6% copper, extending forecast mine life by 50% from eight to twelve years, and delivering stronger project economics through a higher-grade blended production profile. The Project maintains a construction capital cost estimate of USD 474 million, consistent with the January 2026 PFS. The PFS includes Mineral Resources and Mineral Reserves for the Johnny Lee Deposit and updated Mineral Resources and maiden Mineral Reserves for the Lowry Deposit and has been prepared in accordance with NI 43-101. The Project consists of 7,684 hectares of fee simple lands and 1,040 unpatented mining claims totaling 8,078 hectares. The Project is located in south-central Montana in Meagher County, approximately 27 km north of White Sulphur Springs. The Johnny Lee Deposit comprises the Upper Copper Zone at depths of 40–210 m and the Lower Copper Zone at depths of 340–520 m. A Mine Operating Plan application was submitted in December 2015. Following a full Environmental Impact Statement process, a positive MT DEQ Record of Decision was received on April 9, 2020, and on August 14, 2020, the MT DEQ approved bond posting and issued a final Mine Operating Permit permitting Phase I Development surface construction. The MOP proposes underground mining of the Johnny Lee Deposit using a drift-and-fill mining method and production of copper concentrate by milling and froth flotation. Mill tailings will be used for underground paste-fill support, with surplus deposited in a double-lined cemented tailings storage facility. The Lowry Deposit is primarily hosted in the Lowry Middle Copper Zone (MCZ) and Lowry Lower Copper Zone (LCZ). The deposit has not yet been permitted through the MT DEQ. A permitting plan and initial activities are ongoing, with permitting expected to be finalized within six years following commencement of the main Johnny Lee access decline. The Lowry Deposit is not scheduled to commence until seven years after commencement of the Jerry Zieg Decline. The economic analysis uses a copper price assumption of USD 4.70/lb. Initial capital costs are estimated at USD 474 million, sustaining capital at USD 180 million, cash costs at USD 2.68/lb, and life-of-mine all-in sustaining cost at USD 3.04/lb. Payback of start-up capital is achieved approximately four years from commissioning. Combined Probable Mineral Reserves are: Johnny Lee: 9.5 Mt at 2.9% Cu for 270,000 t copper, Lowry: 4.7 Mt at 2.1% Cu for 100,000 t copper, Combined: 14.3 Mt at 2.6% Cu for 370,000 t copper. The updated Lowry Mineral Resource includes 17.9 million tonnes Measured and Indicated at 1.4% copper for 248,000 tonnes copper and 13.7 million tonnes Inferred at 1.1% copper for 151,000 tonnes copper. The Lowry mine plan extracts ore from the MCZ and LCZ using mechanized longhole stoping. Material handling will use trackless underground equipment and 60-tonne haul trucks. All openings will be backfilled with paste backfill to allow complete extraction of the orebody. Metallurgical studies show copper recoveries of 91% copper with a 23% copper concentrate from the Lowry MCZ and 94% copper with a 27% copper concentrate from the Lowry LCZ. Locked-cycle test work indicated that the same flowsheet designed for Johnny Lee can recover copper concentrates grading 23%–28% copper with recoveries of 91%–94% copper. The capital cost estimate remains USD 474 million, including contingency. The breakdown comprises Mining USD 155 million, Process and Infrastructure USD 293 million, and Owner Costs USD 26 million. Development and infrastructure capital for the Lowry Deposit is classified as sustaining capital and does not change the initial capital estimate. Average underground mining operating costs are estimated at USD 70 million per annum, or USD 64/tonne ore mined, excluding capitalized pre-production costs. The updated PFS confirms stronger project economics, higher-grade blended production, extended mine life, and inclusion of the Lowry Deposit into the long-term development plan for the Black Butte Copper Project.