Wallbridge Mining Company Limited press release
Radisson Announces Positive Preliminary Economic Assessment for O'Brien Gold Project
TSX - Toronto Stock Exchange · Gold · Canada
C$532M After-Tax NPV5%, C$175M Initial Capital, Adjacent to Multiple Mills, Still Growing
Rouyn-Noranda, Quebec--(Newsfile Corp. - July 9, 2025) - Radisson Mining Resources Inc. (TSXV: RDS) (OTCQB: RMRDF) ("Radisson" or the "Company") is pleased to announce a positive Preliminary Economic Assessment (the "PEA") for the O'Brien Gold Project ("O'Brien" or the "Project") located in the Abitibi region of Québec. Highlights are as follows (all figures are in Canadian dollars and troy ounces unless noted):
Basis of Study:
Assumes off-site toll milling based on the results of a recent milling assessment and metallurgical study that demonstrated the potential compatibility of the nearby Doyon gold mill, part of IAMGOLD Corporation's ("IAMGOLD") Westwood Mine Complex1. Off-site milling reduces capital costs, development risk, and project footprint. Utilizes existing Mineral Resource Estimate ("MRE"), re-blocked with an updated cut-off yielding more ounces in more tonnes with good continuity at a lower average grade. Presents a base case "snap-shot" study that excludes recent drilling successes outside the existing MRE and below historic mine workings, with a 50-60,000 metre (m) fully funded drill program ongoing.
Value:
After-tax Net Present Value at a 5% discount rate ("NPV5%") of $532 million ("M"), Internal Rate of Return ("IRR") of 48%, and payback of 2.0 yearsat US$2,550/oz gold ("Au"). After-tax NPV5%of $871M, IRR of 74%, and payback of 1.1 yearsat US$3,300/oz Au.
Cost:
Initial Capital Cost ("Capex") of $175Mand Life-of-Mine Sustaining Capital of $173M Cash Cost2of US$861/ozand All-In Sustaining Cost1("AISC") of US$1,059/oz including conceptual 30% toll milling margin on processing and G&A costs. Extremely capital efficient with after-tax NPV5%to Initial Capital Cost ratio of 3.0at US$2,550/oz Au and 5.0at a spot gold price of US$3,300/oz Au.
Production Profile:
11-Year Mine Life with 740 kozmined and 647 kozrecovered at 87%average recovery with a gravity-flotation-regrind-leach flowsheet. 70 koz/annumaverage steady-state gold production (Years 2-8) at an average annual after-tax Free Cash Flow ("FCF") of $97M. Underground mining with long-hole stoping and minimal surface facilities.
Radisson will host a technical webinar on the O'Brien PEA on Wednesday July 9, 2025 at 11am ET (8am PT). Participants may register here. A recording will be available following the webinar.
Matt Manson, President & CEO, commented: "We are pleased to be reporting today the first modern mining study for the O'Brien Gold Project. This PEA builds upon the milling assessment completed earlier this year that demonstrated the potential viability of processing O'Brien mined material at a neighbouring mill. The result is a low cost and high value project should a beneficial milling arrangement be secured. By taking advantage of existing infrastructure in the region, the study surfaces considerable value for O'Brien while minimizing its environmental impact. The extremely high NPV5%to cost ratio demonstrates the efficient allocation of capital that this approach offers.
"Rather than high-grading the deposit, as was the case with the historic O'Brien Mine, the PEA is developed from the existing MRE with a lower cut-off, yielding more ounces, more tonnes and better mining continuity at lower average grades. From that starting point, we are presenting a fully underground mine plan, right sized at 1,200 tonnes per day ("tpd") and optimized at a cautious US$2,000/oz gold price assumption, delivering 740,000 ounces of gold to the mill at high margins over an 11-year life. The O'Brien Gold Project's legacy of high grades and visible gold continues to be an attribute of the current mine design and the ongoing exploration."
Pierre Beaudoin, Chairman of the Board of Directors, commented:_"The PEA announced today is a significant step forward for Radisson. The study outlines a credible mine plan and development strategy for O'Brien, offering shareholders significant value even on the existing mineral resources. This is also just a snap-shot of a project that is continuing to grow. The ongoing drill program is demonstrating impressive new gold mineralization outside the scope of this initial mine design. On the basis upon which the PEA is developed, we believe a significantly larger mineral inventory exists to our exploration horizon of 2,000 m depth. Recent drill results are supporting this thesis."_
Matt Manson continued_: "We see in O'Brien a broad system of mineralization with significant scale potential. Our current focus at Radisson is to maximize this potential through the recently expanded drill program and our strong treasury. Today's PEA, however, establishes a project development path that is practical and highly rewarding. We intend to further pursue this path with environmental baseline studies, additional engineering and mine plan optimization, community consultation, and dialog with potential processing partners."_
VIDEO: President & CEO Matt Manson comments on today's news
O'Brien Gold Project Preliminary Economic Assessment
The PEA was completed by Ausenco Engineering Canada ULC ("Ausenco") as lead consultant with specific responsibility for metallurgy, processing design, infrastructure and financial modelling. InnovExplo (a member of Norda Stelo Inc.; "Norda Stelo") completed the mine design and mine scheduling, BBA Inc. were responsible for water management, surface facilities, and a review of the Project's environmental assessment procedure and permitting requirements, and SLR Consulting (Canada) Ltd. ("SLR") were responsible for the MRE.
The PEA is a companion study to a recently completed milling assessment for the Project in which a metallurgical program was conducted with representative samples of mineralized core from O'Brien. The samples were tested based on a series of flow sheet options which would conceptually be compatible with the nearby Doyon gold mill, part of IAMGOLD's Westwood Mine Complex, with minimal adjustment to the existing Doyon mill configuration. The milling assessment was conducted under a Memorandum of Understanding ("MOU") with IAMGOLD (Radisson news release dated September 9, 2024).The MOU is non-binding and non-exclusive and contains no specific terms around potential commercial arrangements between the parties. The PEA has been completed independently by Radisson and establishes criteria for the development of O'Brien based on processing and tailings management at an existing off-site facility under a toll milling arrangement.
Cautionary statement: Readers are cautioned that the PEA is preliminary in nature, it includes inferred mineral resources that are considered too speculative geologically to have economic considerations applied to them that would enable them to be categorized as mineral reserves, and there is no certainty that the PEA will be realized.
Table 1: Summary of Key Results and Assumptions in the PEA
| Production Data_note 1_ | Values | Units | | | | Life-of-Mine | 11 | Years | | | Total Resource Mined | 4,575 | kt | | | Total Waste Mined | 3,314 | kt | | | Average Head Grade | 5.0 | g/t Au | | | Contained Gold | 740 | koz | | | Recovered Gold | 647 | koz | | | Average Gold Recovery | 87% | | | Years 2-8: Steady State Run-Ratenote2 | Average Production Mining Rate | 1,160 | tpd | | Average Annual Gold Production | 70 | koz | | | Average Head Grade | 4.9 | g/t Au | | | Annual Average After-Tax Free Cash Flow | $97 | C$M | | | Capital Costs_note 1_ | Values | Units | | | | Initial Capital | $175 | C$M | | | Sustaining Capital (Excluding Closure) | $173 | C$M | | | Capital Intensity (Initial Capital/oz milled) | $172 | US$/oz | | Life-of-Mine Operating Costs_notes 1_,3 | Values | Units | | | | Mining_note 3_ | $76 | C$/t milled | | | Processing | $38 | C$/t milled | | | G&A | $31 | C$/t milled | | | 30% Processing Toll_note 4_ | $19 | C$/t milled | | | Total Operating Cost | $163 | C$/t milled | | | Refining & Transport | $6 | US$/oz | | | Royalties | $10 | C$M | | | Total Cash Cost | $861 | US$/oz | | | All-In Sustaining Cost_note 5_ | $1,059 | US$/oz | | Financial Analysis_note 1_ | Values | Units | | | | Gold Price for Financial Analysis | $2,550 | US$/oz | | | US$:C$ Exchange | $0.73 | | | | Pre-Tax NPV5% | $782 | C$M | | | Pre-Tax IRR | 65% | | | | Pre-Tax Payback | 1.4 | years | | | After-Tax NPV5% | $532 | C$M | | | After-Tax IRR | 48% | | | | After-Tax Payback | 2.0 | years | | | Mine Revenue | $2,258 | C$M | | | EBITDA | $1,496 | C$M | | | EBITDA Margin | 66% | | | | Pre-Tax Unlevered Free Cash Flow | $1,146 | C$M | | | After-Tax Unlevered Free Cash Flow | $803 | C$M |
Notes:
1. Denotes a "specified financial measure" within the meaning of NI 52-112. See note on "Non-IFRS Financial Measures". 2. Represents full calendar years 3. LOM operating costs includes cash operating costs during the initial capital period. Mining operating costs exclude waste development costs and mobile equipment costs which are captured as sustaining capital items 4. Processing toll milling charges are conceptual and have been estimated by Ausenco based on recent industry precedent 5. AISC includes Royalties, Total Cash Costs and Sustaining Capital, including closure costs. Excludes corporate G&A.
Mineral Resources
The MRE for the Project was originally disclosed in March 2023 (Radisson news release dated March 2, 2023) based on 325,509 m of drilling completed to the end of 2022 and authored by SLR. Indicated Mineral Resources were estimated at 0.50 million ounces (1.52 million tonnes at 10.26 g/t Au) with additional Inferred Mineral Resources of 0.45 million ounces (1.60 million tonnes at 8.66 g/t Au). The 2023 study utilized a 4.5 g/t Au cut-off at US$1,600/oz Au with certain assumptions for minimum mining width, mining costs, C$:US$ exchange and metallurgical recovery. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
For the purposes of the PEA, the 2023 block model was re-blocked by SLR in the Z-direction to 5 m to allow for more flexible underground mine design, and an updated cut-off and set of economic criteria were applied consistent with Deswick Stope Optimizer ("DSO") parameters used for the optimization of the underground mine schedule and the Project's recent milling assessment. The MRE now utilizes a cut-off of 2.2 g/t Au at US$2,000/oz Au. No other changes were made. This has the effect of increasing tonnage and ounces and decreasing average grade compared to the previous estimate (Table 2).
Table 2: Mineral Resource Estimate Using a 2.2 g/t Au Cut-Off and US$2,000/oz Gold Price (Numbers in Italics Represent Changes from the MRE based on a 4.5 g/t Au Cut-Off and US$1,600/oz Gold Price.)
| Category | Tonnes (kt) | Grade (g/t Au) | Oz (koz Au) | | | | | Indicated | 2,204 | +45% | 8.2 | -20% | 582 | +16% | | Inferred | 6,671 | +317% | 4.4 | -50% | 932 | +109% |
Notes:
1. Prepared in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Definition Standards (2014) and Best Practice Guidelines of Mineral Resources and Reserves (2019). 2. Mineral Resources are reported above a cut-off grade of 2.2 g/t Au based on a C$172.5/t operating cost. 3. Mineral Resources are estimated using a long-term gold price of US$2,000/oz Au, a US$:C$ exchange rate of 1:1.33, and a metallurgical recovery of 90%. 4. Wireframes were modelled at a minimum width of 1.2 m. 5. Bulk density varies by deposit and lithology and ranges from 2.00 t/m³ to 2.82 t/m³. 6. Full length composites were capped 40 g/t Au. 7. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. 8. Numbers may not add due to rounding.
Between the end of 2022 and the present, Radisson completed approximately 50,000 m of additional drilling at the Project. Drilling that was completed within the volume of the MRE is assessed to have no material impact on the overall contained mineral resource, such that the MRE is appropriate in SLR's opinion for mine planning. Drilling that was completed outside the volume of the MRE, including below the level of the historic mine workings at O'Brien, has indicated the presence of significant additional gold mineralization that is not incorporated in the current conceptual mine plan. Radisson expects to complete a further 50,000-60,000 m of drilling in 2025 and 2026, at which time the Company expects to complete an updated MRE.
Mining
The PEA describes an 11-year mine life based on the mining of 4.57 Mt of mineralized material and 3.31 Mt of waste rock (Table 3). Mining will be fully underground with long-hole stoping and a cemented rock backfill. Stope design is benefitted by good spatial continuity of reported resource blocks at the lower cut-off grade. Minimum and average stope widths are 2.2 m and 2.7 m respectively, including 0.7 m of planned dilution. The mine will be accessed by way of twin 4.5 m by 4.5 m ramps from surface to a depth of 950 m with 86 kilometres (km) of development. Mining equipment includes 20 tonne trucks with rock haulage assisted by vertical conveyors delivering mined material from the 300 m level to a surface run-of-mine pad. The underground mine design does not incorporate any infrastructure from the historic O'Brien Mine. A shaft at the historic Kewagama Mine site east of O'Brien will be reused for ventilation. Mined material will be trucked by road for processing.
Table 3: Mined Material
| Material | Tonnes (kt) | Oz (koz Au) | Head Grade (g/t Au) | | Production Stopes | 3,146 | 588 | 5.8 | | Marginal Stopes | 169 | 16 | 2.9 | | Development | 469 | 91 | 6.0 | | Low-Grade Development | 790 | 45 | 1.8 | | Total Mineralized Mined Material | 4,575 | 740 | 5.0 | | Waste | 3,314 | n/a | n/a |
[](https://images.newsfilecorp.com/files/10977/258183_1e2a85bb743ed9d7_002full.jpg)
Figure 1:Annual Average Production Schedule
To view an enhanced version of this graphic, please visit: https://images.newsfilecorp.com/files/10977/258183_1e2a85bb743ed9d7_002full.jpg
The underground mine was designed and production scheduled on the basis of a DSO optimization at US$2,000 Au and production cut-off grades of 3.05 g/t Au and 3.11 g/t Au depending on the royalty to be considered. "Mined Material" is categorized as Production Stope Material, Marginal Stope Material, Development Material, Low-Grade Development Material and Waste. In Years 2-8 during which the Project maintains steady-state operation, production from stopes averages 1,160 tpd. However, the PEA contemplates up to 2,000 tpd of mill capacity. Consequently, all mineralized mined material is scheduled for processing (Figure 1), resulting in an average head grade of 5.0 g/t Au, delivering an average of 1,410 tonnes of mined material daily to the mill, and eliminating the requirement for a low-grade stockpile.
Mineral Resources not included in the mine plan are those considered too isolated or too marginal at a US$2,000/oz DSO optimization. The mine design also excludes Mineral Resources located in the former Thompson Cadillac mine area or in areas considered too close to the historic workings. The quantity of mineralized mined material in the mine design is highly sensitive to the gold price assumption, with the DSO optimization delivering significantly more mined material in both existing production stopes and development areas, as well new stopes and development areas, at higher gold prices.
Infrastructure and Site Facilities
The Project is located adjacent to the Trans-Canada Highway 117 and has existing road access to the historic O'Brien mine site. The PEA contemplates twin underground mine portals located 2 km to the east of the historic site, with new haul roads, a waste rock pad, a run-of-mine pad, laydown areas, the surface installation of a vertical conveyor, trenches and sumps for water management, and a waste-water treatment plant. The PEA does not contemplate a mill, tailings deposition, accommodation camp, or major maintenance facilities. Small vehicle maintenance and site offices/mine dry will be provided from existing facilities or temporary modules. A new substation will derive power from the adjacent 112 kV high voltage transmission line operated by Hydro-Québec.
Processing_(See footnote 1)_
The PEA contemplates processing and tailings deposition at an off-site facility. To assess the viability of this scenario, Radisson conducted a metallurgical study and milling assessment under the auspices of an MOU with IAMGOLD to assess the design criteria for processing O'Brien mined material at the nearby Doyon gold mill, the processing facility for IAMGOLD's Westwood Mine Complex. The Doyon mill is located 21 km west of O'Brien and directly accessible along Trans-Canada Highway 117.
The metallurgical results of this milling assessment were previously reported (see Radisson news release dated February 3, 2025) and are incorporated into the PEA. Gold recoveries of between 86% and 96% were obtained based on a series of flow sheet options, all of which are compatible with the Doyon mill with minimal or modest additional capital. The metallurgical program was undertaken at the Lakefield, Ontario facilities of SGS Canada Inc. under the supervision of Ausenco.
The Doyon mill currently operates at approximately 3,000 tpd with a conventional cyanidation process. Mined material is processed with a primary crusher and a two-stage semi-autogenous SAG mill/Ball mill grinding at 75 µm (P80). Leaching is by way of two stage Carbon-in-Leach and Carbon-in-Pulp circuits. The PEA contemplates a Gravity-Flotation-Regrind-Leach flow sheet and assumes Radisson deploying $21M of capital to upgrade the gravity and flotation circuits at Doyon that have been used previously but are currently inactive.
The Doyon mill currently processes approximately 1,000 tpd from the underground Westwood mine and approximately 2,000 tpd from the nearby Grand Duc open pit. Processing of Grand Duc material is estimated to be completed in early 2027, as outlined in the Westwood Mine Complex technical report dated September 30, 2024. Hence, the PEA envisions up to 2,000 tpd of mill capacity available for O'Brien at Doyon, allowing for the direct shipment of both production material _and_lower grade development material at an average of 1,400 tpd. The PEA does not anticipate the stockpiling of low-grade mined material at the O'Brien site, resulting in a significant cost saving.
Life-of-mine average gold recovery with the Gravity-Flotation-Regrind-Leach flowsheet is estimated at 87%. This is based on 90% recovery for the O'Brien metallurgical sample at an average grade of 6.3 g/t Au and the application of a grade-recovery model to the average head-grade expected in the PEA of 5.0 g/t Au after the processing of low-grade development materials.
O'Brien gold mineralization is associated with pyrite and arsenopyrite. The metallurgical program determined average arsenic values of 0.4% to 0.5% in whole rock, relevant if material is being sent to tailings deposition on-site, and 4.6% in flotation concentrate, relevant if a concentrate is being sold to an off-take agent. These values are consistent with precedent projects in Québec's Abitibi and offtake threshold limits for concentrates of high-grade gold projects. The PEA contemplates tailings deposition after leach without a segregated tailings impoundment. If one is required, additional capital expenses would be incurred.
The PEA contains estimates of operating and capital costs for trucking, processing, tailings management and G&A developed by Ausenco from first principles based on the metallurgical results and precedent projects. These costs correspond well to recently reported operating results from the Doyon facility. The PEA's financial results reflect an additional 30% charge on processing and G&A costs, corresponding to approximately $19/t, to reflect the impact of a potential toll milling charge. The MOU between Radisson and IAMGOLD contains no specific terms around potential commercial arrangements between the Parties, including the use of the Doyon mill or the terms of potential toll-milling. There is no certainty that any arrangement between the Parties will result from their dealings pursuant to the MOU, which is non-binding and non-exclusive.