Osisko Lynx 600 Stage Bulk Pattern Averages 65.5 g/t Au

169%

Reconciliation vs Grade

in Mineral Useful resource Estimate

10,135 ounces Gold and 4,378 ounces Silver Contained inside 4,809 tonnes

TORONTO, Oct. 27, 2022 (GLOBE NEWSWIRE) — Osisko Mining Inc. (OSK:TSX “Osisko” or the “Company”) is happy to supply new outcomes from the persevering with exploration program at its 100% owned Windfall gold challenge positioned within the Abitibi greenstone belt, City Township, Eeyou Istchee James Bay, Québec.

Highlights

Outcomes from processing 4,809 tonnes mined from Triple Lynx (the “bulk pattern”) introduced in Desk 1 and Desk 2, have exceeded technical expectations. The pattern produced a constructive reconciliation of 169%, returning a mean grade of 65.5 g/t Au, properly above the expected capped grade based mostly on the 12.5-metres infill mannequin utilizing the identical block mannequin parameters as the present mineral useful resource estimate “MRE” (technical report filed on SEDAR beneath Osisko’s issuer profile on September 14, 2022). Vital visible gold mineralization was encountered alongside the size of the mined stope. Highlights and full outcomes are introduced under, diagrams and sections could be discovered at www.osiskomining.com.

Desk

1:

Lynx

Bulk

Pattern

Reconciled Outcomes

Mill feed tonnages used within the pattern processing reconciliation have been offered by Northern Solar. Day and evening shift each day composite samples collected in the course of the processing of the majority pattern have been assayed by exterior impartial laboratories. Bulk pattern outcomes have been reconciled by Soutex Inc., an exterior impartial marketing consultant utilizing Bilmat.

Osisko Chairman and Chief Govt Officer John Burzynski commented: “On the again of our strongly constructive MRE introduced in late August and the numerous new high-grade down plunge intercepts in September (Osisko information launch dated September 27, 2022), at the moment’s bulk pattern outcomes underscore the potential for Windfall to develop into one of many largest and highest-grade underground gold deposits in Canada. The grade has – for the third time in as many bulk samples – considerably exceeded expectations based mostly on capped drilling block fashions. The empirical outcomes from our bulk samples have constantly returned robust constructive reconciliations, and provides robust assist to the prevailing geological mannequin. They’ve proved invaluable in growing our confidence within the grade, continuity and predictability of the mineralized zones at Windfall.”

Geology

The Triple Lynx wireframe 3161 bulk pattern is characterised by a West-South-West oriented mineralization hall reasonably dipping to the north, with a mean width of three.3 metres. Banded gray quartz veins comprise 5 – 15% pyrite, hint chalcopyrite and native seen gold. The mineralization is hosted inside a granodiorite dyke and gabbro, each displaying robust sericite and silica alteration.

Processing

A complete of 4,809 tonnes of mineralized materials have been processed in September 2022 on the Northern Solar Redstone concentrator, producing gravity and flotation concentrates. The reconciled head grade obtained from the processed pattern is 65.5 g/t Au and 28.3 g/t Ag. The pattern contained 10,135 oz Au and 4,378 oz Ag, with a complete of 9,439 oz Au and three,864 oz Ag recovered. Reconciled recoveries are 93.1% for gold and 88.2% for silver. The Windfall MRE metallurgical take a look at work thought-about a communition, gravity and leaching circuit course of flowsheet, giving a mean restoration of 96.4% for the Lynx zone. Check mill availability dictated using a mill with a communition, gravity and flotation flowsheet. The reconciled outcomes from the processing of the majority pattern materials are introduced in Desk 1.

Block

Mannequin

The majority pattern was taken from Triple Lynx mineralization wireframe 3161 of the Windfall MRE. The pattern space was infill drilled at 12.5-metres spacings and predicted to comprise 4,800 tonnes averaging 38.9 g/t Au, and 6,009 ounces of gold (Desk 2).

Desk

2:

Infill

Useful resource

Block

Mannequin

Predictions

vs. Processed Materials

Concentrates

Each the gravity concentrates and flotation focus produced from the pattern are thought-about high- grade. The gravity focus averaged 14,339 g/t Au (461.0 oz/t Au), whereas the flotation focus averaged 408.2 g/t Au (13.1 oz/t Au).

Mining

and

Grade Management

The Triple Lynx bulk pattern was mined utilizing lengthy gap mining strategies. Two improvement drifts have been mined conventionally at 20 metres floor-to-floor vertical intervals between 580 and 600 metres under floor. Whereas mining the event drifts, sampling of the face was accomplished to check the width and grade of the mineralization. A V30 borehole was used within the slot increase and three-inch manufacturing holes have been drilled down and blasted. The blasted ore was retrieved utilizing a distant scoop tram, sampled, trucked to a floor stockpile, then trucked to the Northern Solar mill web site.

Earlier Bulk Samples

All three bulk samples accomplished by Osisko have reconciled positively. Desk 3 summarizes Windfall’s three bulk pattern outcomes, which have returned in combination 14,914 ounces gold and eight,004 ounces silver from a mixed 16,025 tonnes, or a mean of 0.93 ounces Au per tonne and 0.50 ounces Ag per tonne, with a mean gold restoration of 94.1 p.c, and common silver restoration of 90.8 p.c.

Desk

3:

Bulk Samples Accomplished at Windfall

*See Osisko information releases dated June 11, 2019, and December 11, 2019, respectively.

Certified Particular person

The scientific and technical content material of this information launch has been reviewed, ready and accredited by Kim-Quyên Nguyên, MBA., P.Eng. (OIQ 146014), Venture Director for Osisko, who’s a “certified individual” inside the which means of Nationwide Instrument 43-101 – Requirements of Disclosure for Mineral Tasks (“NI 43-101”). The block mannequin within the bulk space of the Triple Lynx zone, with an efficient date of February 3, 2022, was ready by Judith St-Laurent, P.Geo (OGQ #1023), Director of Mineral Useful resource Estimation of Osisko Mining, who’s a “certified individual” inside the which means of NI 43-101. The scientific and technical content material on this information launch has been reviewed and accredited by Mr. Mathieu Savard, P.Geo (OGQ #510), President of Osisko Mining, who’s a “certified individual” inside the which means of NI 43-101.

Technical Information, High quality Management and Reporting Protocols

Course of reconciliation was carried out utilizing Bilmat software program by Soutex Inc., an exterior marketing consultant. A reconciled stability was calculated for every day and evening shift in addition to for the general bulk pattern processing. Day and evening shift mill throughput was estimated utilizing the load cell on the Redstone main ball mill feed conveyor. Composite samples have been taken every day and evening shift on the streams required for the reconciliation. The entire amount of fabric processed was estimated based mostly on the Redstone Mill truck scale which has been calibrated earlier than the majority pattern processing. The flotation focus was bagged and weighed on the identical truck scale and drill samples have been taken from every bag. The gravity focus baggage have been weighed on a scale and every bag was drill sampled. The fabric remaining within the gear on the finish of the majority processing after the clean-up was collected in baggage, weighed, and sampled. All samples have been despatched out to an exterior impartial lab for preparation and assaying. All shift samples have been assayed for gold, silver, iron, sulfur, and moisture. The drill samples from the baggage have been assayed for gold, silver and moisture. Gold assay from all streams besides the rougher flotation feed and tails was obtained by screened metallics fireplace assay. Remaining course of cleansing baggage information was redistributed by way of the flotation focus.

About Windfall

The Windfall gold deposit is positioned between Val-d’Or and Chibougamau within the Abitibi area of Québec, Canada. The MRE for Windfall is supported by the technical report titled “NI 43-101 Technical Report, Mineral Useful resource Estimate for the Windfall Venture”, dated September 14, 2022 (with an efficient date of June 7, 2022), ready for the Company by BBA Inc. and PLR Assets Inc. (the “Windfall MRE (2022)”), and assuming a cut-off grade of three.50 g/t Au, includes 811,000 tonnes at 11.4 g/t Au (297,000 ounces) within the measured mineral useful resource class, 10,250,000 tonnes at 11.4 g/t Au (3,754,000 ounces) within the indicated mineral useful resource class and 12,287,000 tonnes at 8.4 g/t Au (3,337,000 ounces) within the inferred mineral useful resource class. The important thing assumptions, parameters and strategies used to estimate the MRE for Windfall are additional described within the Windfall MRE (2022), being the total technical report for this up to date MRE ready in accordance with NI 43-101 and is on the market on SEDAR (www.sedar.com) beneath Osisko’s issuer profile. The Windfall gold deposit is at present one of many highest-grade resource-stage gold tasks in Canada and has world-class scale. Mineralization happens in three principal areas: Lynx, Fundamental, and Underdog. Mineralization is usually comprised of sub-vertical lenses following intrusive porphyry contacts plunging to the northeast. The assets are outlined from floor to a depth of 1,600 metres, together with the Triple 8 (TP8) zone. The assets excluding TP8 are outlined from floor to a depth of 1,200 metres. The deposit stays open alongside strike and at depth. Mineralization has been recognized at floor in some areas and as deep as 2,625 metres in others with important potential to increase mineralization down-plunge and at depth.

About Osisko Mining Inc.

Osisko is a mineral exploration firm centered on the acquisition, exploration, and improvement of treasured steel useful resource properties in Canada. Osisko holds a 100% curiosity within the high-grade Windfall gold deposit positioned between Val-d’Or and Chibougamau in Québec and holds a 100% undivided curiosity in a big space of claims within the surrounding the City Barry space and close by Quévillon space (over 2,400 sq. kilometres).

Cautionary Notice Relating to Ahead-Wanting Info

This information launch incorporates “forward-looking data” inside the which means of the relevant Canadian securities laws that’s based mostly on expectations, estimates, projections and interpretations as on the date of this information launch. The data on this information launch concerning the potential for Windfall to develop into one of many largest and highest-grade underground deposits in Canada; the Windfall gold deposit being one of many highest grade resource-stage gold tasks in Canada; the importance of the outcomes from the majority pattern described on this information launch; the majority pattern having the next than anticipated grade; any prediction arising from the majority pattern; the common grade of the majority pattern having any predictive worth; the MRE for Windfall being presumably conservative on the grade of the deposit; the geology of the majority pattern; the deposit remaining open alongside strike and at depth; potential depth extensions of the mineralized zones down-plunge and at depth; potential mineralization; the flexibility to comprehend upon any mineralization in a fashion that’s financial; the flexibility to finish any proposed exploration actions and the outcomes of such actions, together with the continuity or extension of any mineralization; and some other data herein that’s not a historic reality could also be “forward-looking data”. Any assertion that includes discussions with respect to predictions, expectations, interpretations, beliefs, plans, projections, goals, assumptions, future occasions or efficiency (usually however not at all times utilizing phrases comparable to “expects”, or “doesn’t anticipate”, “is predicted”, “interpreted”, “administration’s view”, “anticipates” or “doesn’t anticipate”, “plans”, “finances”, “scheduled”, “forecasts”, “estimates”, “believes” or “intends” or variations of such phrases and phrases or stating that sure actions, occasions or outcomes “could” or “might”, “would”, “would possibly” or “will” be taken to happen or be achieved) usually are not statements of historic reality and could also be forward-looking data and are supposed to establish forward-looking data. This forward- wanting data relies on cheap assumptions and estimates of administration of the Company on the time such assumptions and estimates have been made, and includes recognized and unknown dangers, uncertainties and different elements which can trigger the precise outcomes, efficiency or achievements of Osisko to be materially completely different from any future outcomes, efficiency or achievements expressed or implied by such forward-looking data. Such elements embody, amongst others, dangers referring to the flexibility of exploration actions (together with drill outcomes and bulk samples) to precisely predict mineralization; errors in administration’s geological modelling; the flexibility of Osisko to finish additional exploration actions, together with drilling; property pursuits within the Windfall challenge; the flexibility of the Company to acquire required approvals and full transactions on phrases introduced; the outcomes of exploration actions; dangers referring to mining actions; the worldwide financial local weather; steel costs; dilution; environmental dangers; and neighborhood and non-governmental actions. Though the forward-looking data contained on this information launch relies upon what administration believes, or believed on the time, to be cheap assumptions. Osisko can not guarantee shareholders and potential purchasers of securities of the Company that precise outcomes will probably be in step with such forward-looking data, as there could also be different elements that trigger outcomes to not be as anticipated, estimated or supposed, and neither Osisko nor some other individual assumes duty for the accuracy and completeness of any such forward-looking data, Osisko doesn’t undertake, and assumes no obligation, to replace or revise any such forward-looking statements or forward-looking data contained herein to mirror new occasions or circumstances, besides as could also be required by regulation.

For additional data please contact:

John Burzynski Chairman and Chief Govt Officer Phone: (416) 363-8653