# i-80 Gold Announces Positive Feasibility Study and Initial Mineral Reserves for Granite Creek Underground; After-Tax NPV\(5%\) of $118 Million at $2,750/oz Au Increasing to $598 Million at $4,500/oz Au Canonical Atlas analysis: https://atlas-extractions.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--df64229e-8429-4dcb-92e8-10100965eff1 Original source: https://www.newswire.ca/news-releases/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for-granite-creek-underground-after-tax-npv-5-of-118-million-at-2-750-oz-au-increasing-to-598-million-at-4-500-oz-au-845034358.html Publisher: cnw Original announcement: 2026-09-21T23:45:52.963Z Analysis by Minestarters Atlas Atlas analysis published: Unknown date Atlas analysis updated: Unknown date - Company: i-80 Gold - Ticker: IAUX - Exchange: Unavailable - Region: Nevada - Primary commodity: Gold - Secondary commodities: None reported - Document categories: Economic study, Resource update, Metallurgy - Extracted: 2026-09-21 23:48:37 UTC Narrative sentiment: 0.80 · Bullish ## Minestarters Atlas summary i-80 Gold announced positive results from a Feasibility Study for its Granite Creek Underground gold project, outlining an after-tax NPV\(5%\) of $118 million at a $2,750/oz gold price. The study reports initial Proven and Probable Mineral Reserves of 2.20 Mt grading 7.87 g/t Au for 556,500 oz, and a 229% increase in Measured and Indicated Resources to 3.73 Mt grading 7.17 g/t Au for 859,500 oz. The project has an 8.5-year mine life with average annual gold production of 75,000 oz \(2028-2032\) and LOM AISC of $2,273/oz \(excluding Lone Tree refurbishment capital\), supported by an optimized processing strategy at the company's Lone Tree Plant. Reasoning: The document announces positive results from a Feasibility Study for the Granite Creek Underground gold project, including robust economics, a significant increase in Measured and Indicated resources, and an initial Mineral Reserve estimate. The study outlines a clear path to production with an optimized processing strategy. While the base case gold price is high, the overall results are very positive for the company. - Positive factor: Positive Feasibility Study results with robust economics at base case gold price. - Positive factor: Significant increase in Measured and Indicated Mineral Resources. - Positive factor: Initial Mineral Reserve estimate provides a solid foundation for mine life. - Positive factor: Optimized processing strategy with planned commissioning of wholly-owned Lone Tree Plant expected to reduce costs. - Negative factor: Inferred Mineral Resources decreased, indicating conversion but also a reduction in speculative upside. - Negative factor: Study relies on a gold price of $2,750/oz, which is above current spot prices, though sensitivities are provided. Low confidence — this extraction should be reviewed alongside the original source. Facts used in scoring: 5 ## Classification and evidence **DFS Bankable** Polarity: positive Definition: AACE Class 2-1 study complete and within the staleness window. Why it applies: The document announces the results of a feasibility study prepared under NI 43-101, which constitutes a feasibility study \(FS\). Evidence · text > The results announced in this press release are supported by two technical reports prepared for Granite Creek Underground: \(1\) a technical report prepared under National Instrument 43-101 – Standards of Disclosure for Mineral Projects \("NI 43-101"\) which, in the opinion of the qualified persons, constitutes a feasibility study under NI 43-101 \(the "NI 43-101 FS" or the "FS"\) **High IRR** Polarity: positive Definition: Post-tax real unlevered IRR in the strong tier or better. Why it applies: The after-tax NPV\(5%\) of $118 Million at $2,750/oz Au is a strong economic indicator for the project. Evidence · text > After-Tax NPV\(5%\) of $118 Million at $2,750/oz Au **Long Reserve Life** Polarity: positive Definition: Reserve life index in the top tier of the single ladder. Why it applies: The mine life is approximately 8.5 years, which is considered adequate. Evidence · table > 8.5 Context: Mine Life **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: The Mineral Reserves were estimated by Anton Chan, a Qualified Person under NI 43-101 and S-K 1300. Evidence · text > The Mineral Reserves were estimated by Anton Chan, B.Eng, M.Sc., P.Eng, MMSAQP \(\#01546 QP \) of SRK Consulting, U.S. \(Inc.\), a Qualified Person under NI 43-101 and S-K 1300. **JORC Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with JORC Code \(Australia\) — high reporting standard. Why it applies: The resource estimate was prepared in compliance with NI 43-101 and S-K 1300. Evidence · text > a Qualified Person under NI 43-101 and S-K 1300. **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: The resource estimate was prepared in compliance with NI 43-101 and S-K 1300. Evidence · text > a Qualified Person under NI 43-101 and S-K 1300. **Measured Resource** Polarity: positive Definition: Highest confidence category — tonnage, grade, shape well-established from closely-spaced drilling. Basis for Proven Reserves. Why it applies: The resource estimate includes a Measured category. Evidence · table > Measured Context: Measured **Indicated Resource** Polarity: positive Definition: Reasonable geological confidence based on adequate drilling; continuity can be assumed. Basis for Probable Reserves. Why it applies: The resource estimate includes an Indicated category. Evidence · table > Indicated Context: Indicated **Proven Reserve** Polarity: positive Definition: Measured Resource with demonstrated economic viability after applying modifying factors. Why it applies: The reserve estimate includes a Proven category. Evidence · table > Proven Context: Proven **Probable Reserve** Polarity: positive Definition: Indicated Resource with demonstrated economic viability after applying modifying factors. Why it applies: The reserve estimate includes a Probable category. Evidence · table > Probable Context: Probable **Inferred Resource** Polarity: negative Definition: Speculative category — limited drilling, geological continuity assumed but not confirmed. Cannot support economic studies alone. Why it applies: The resource estimate includes an Inferred category. Evidence · table > Inferred Context: Inferred **Category Upgrade** Polarity: positive Definition: Resource confidence improved — Inferred upgraded to Indicated, or Indicated to Measured. De-risking signal. Why it applies: Measured and Indicated underground Mineral Resources increased by 229% and Inferred Mineral Resources decreased by 38% as material was converted into higher classification categories. Evidence · text > Measured and Indicated underground Mineral Resources increased by 229% to 3.73 Mt grading 7.17 g/t Au containing 859,500 oz Au, compared to the PEA \(1\) ; Inferred Mineral Resources decreased by 38% to 0.89 Mt grading 7.06 g/t Au containing 202,800 oz Au as the infill program converted a portion of Inferred Mineral Resources into the higher classification categories. **High Recovery** Polarity: positive Definition: Recovery at or above the exceptional band for the commodity and processing route. Why it applies: The average gold recovery is 87%, which is strong for gold processing. Evidence · table > 87 % Context: Average Gold Recovery **Refractory Ore** Polarity: negative Definition: Ore requires oxidation/pressure treatment before recovery — a processing and recovery risk. Why it applies: The metallurgical testing demonstrated that the ore contains predominantly single refractory material requiring an oxidation process. Evidence · text > Metallurgical testing has demonstrated that the Ogee, Otto and South Pacific zones at Granite Creek Underground contain predominantly single refractory material and require an oxidation process to increase gold extraction using cyanidation. **Mill Route** Polarity: neutral Definition: Processing via mill or concentrator \(CIL, CIP, tank leach, flotation\). Why it applies: The processing strategy involves the Lone Tree autoclave and carbon-in-leach \(CIL\) plant. Evidence · text > Lone Tree autoclave and carbon-in-leach plant **POX/BIOX Route** Polarity: neutral Definition: Pressure or bio-oxidation for refractory ore — high CAPEX and OPEX. Why it applies: The processing involves an acid pressure oxidation \(POX\) process. Evidence · text > acid pressure oxidation \("POX"\) conditions **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: A current resource fact retains the disclosed cut-off grade **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: The source explicitly discloses a revised resource estimate Evidence · text > Updated Mineral Resource Estimate **Gravity Route** Polarity: neutral Definition: Gravity separation forms a material part of the flowsheet. Why it applies: the document describes a gravity route \("gravity"\) ## Extracted facts Stored fact records: 3. Some facts used in scoring do not have a stored record. ## Resource Estimates (2) ### proven [Link to this fact](https://atlas-extractions.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--df64229e-8429-4dcb-92e8-10100965eff1#fact-resource-facts-2) Granite Creek Underground · gold #### Identity - Project: Granite Creek Underground - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: IAUX #### Resource scope - Estimate type: reserve - Effective date: 2026-03-31T00:00:00.000Z - Reporting standards: ni\_43\_101, sec\_sk1300 - QP Signed: Yes - Qualified person names: Anton Chan - Resource group id: resource:51bf406f6b1ef3faa4f2 - Deposit or zone: South Pacific - Mining method: underground - Resource basis: attributable #### Resource Data - Category: proven - Tonnes: 40000 - Grade: 11.21 - Grade Unit: g/t - Contained Metal: 14.5 - Contained Unit: koz - Cutoff Grade: 4.42 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2026-03-31 #### Lab - Laboratory: SRK Consulting, U.S. \(Inc.\) #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2026-09-21T00:00:00.000Z Reasoning: The South Pacific zone contributes a high-grade Proven Reserve, showcasing the quality of mineralization in this area, despite a smaller tonnage. - Positive factor: Very high-grade Proven Reserve in the South Pacific zone, indicating rich mineralization. #### Tags used in scoring **Proven Reserve** Polarity: positive Definition: Measured Resource with demonstrated economic viability after applying modifying factors. Why it applies: category is "proven" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ### measured [Link to this fact](https://atlas-extractions.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--df64229e-8429-4dcb-92e8-10100965eff1#fact-resource-facts-3) Granite Creek Underground · gold #### Identity - Project: Granite Creek Underground - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: IAUX #### Resource scope - Estimate type: resource - Effective date: 2026-03-31T00:00:00.000Z - Reporting standards: ni\_43\_101, sec\_sk1300 - QP Signed: Yes - Qualified person names: Benjamin Parsons - Resource group id: resource:fa91e1284023c8939dca - Deposit or zone: South Pacific - Mining method: underground - Resource basis: attributable #### Resource Data - Category: measured - Tonnes: 65000 - Grade: 9.85 - Grade Unit: g/t - Contained Metal: 20.7 - Contained Unit: koz - Cutoff Grade: 3.75 - Cutoff Unit: g/t #### Prior Estimate - Resource Date: 2026-03-31 #### Lab - Laboratory: SRK Consulting, U.S. \(Inc.\) #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2026-09-21T00:00:00.000Z Reasoning: The South Pacific zone contributes a high-grade Measured Resource, highlighting the quality of mineralization in this area with high confidence. - Positive factor: Very high-grade Measured Resource in the South Pacific zone, indicating excellent mineralization quality. #### Tags used in scoring **Measured Resource** Polarity: positive Definition: Highest confidence category — tonnage, grade, shape well-established from closely-spaced drilling. Basis for Proven Reserves. Why it applies: category is "measured" **Cut-off Disclosed** Polarity: positive Definition: Cut-off grade used for resource reporting is clearly stated, enabling like-for-like comparison. Why it applies: cutoff\_grade is stated **QP/CP Signed** Polarity: positive Definition: Qualified Person \(QP\) or Competent Person \(CP\) named and signed off — a member of a recognized professional association \(e.g., AusIMM, SME, AIG, P.Geo\) with relevant experience. Why it applies: qp\_signed is true **NI 43-101 Compliant** Polarity: positive Definition: Resource estimate prepared in compliance with NI 43-101 \(Canada\) — high reporting standard. Why it applies: reporting\_standards includes ni\_43\_101 **Resource Update** Polarity: neutral Definition: Revised estimate for an existing resource — compare to prior to assess progress. Why it applies: the release compares against a previous estimate **PEA-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Preliminary Economic Assessment — early-stage study. Why it applies: the release names the study this estimate supports **PFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Pre-Feasibility Study — requires adequate M&I component. Why it applies: the release names the study this estimate supports **DFS-Supporting** Polarity: neutral Definition: Resource estimate prepared to support a Definitive Feasibility Study — requires high M&I confidence. Why it applies: the release names the study this estimate supports ## Metallurgical Results (1) ### autoclave [Link to this fact](https://atlas-extractions.minestarters.com/news/i-80-gold-announces-positive-feasibility-study-and-initial-mineral-reserves-for--df64229e-8429-4dcb-92e8-10100965eff1#fact-metallurgical-facts-4) Granite Creek Underground · gold #### Identity - Project: Granite Creek Underground - Commodity: gold - Region: usa\_nv - Reported Region: Nevada - Ticker: IAUX #### Test Work - Program Status: detailed - Test Type: autoclave - Processing Route: acid pressure oxidation \(POX\) and carbon-in-leach \(CIL\) #### Recovery - Recovery: 87 % - Recovery Basis: actual\_test - Head Grade: 7.87 - Head Grade Unit: g/t Au #### Lab - Laboratory: SRK Consulting, U.S. \(Inc.\) - Consultant: SRK Consulting, U.S. \(Inc.\) #### Review - Needs Review: No - Historical: No #### Dates - Event date: 2026-09-21T00:00:00.000Z Reasoning: The metallurgical results show a high average gold recovery, which is a strong positive for the project's economics. The optimized processing strategy, including the use of the Lone Tree Plant, is expected to improve cost efficiency, despite the refractory nature of the ore. - Positive factor: High average gold recovery of 87% for the LOM, indicating efficient processing. - Positive factor: Processing strategy optimized to use the company's wholly-owned Lone Tree Plant, reducing reliance on third-party processing. - Negative factor: Ore is predominantly single refractory material, requiring an oxidation process. #### Tags used in scoring **Mill Route** Polarity: neutral Definition: Processing via mill or concentrator \(CIL, CIP, tank leach, flotation\). Why it applies: processing\_route matches the mill\_cil signal **POX/BIOX Route** Polarity: neutral Definition: Pressure or bio-oxidation for refractory ore — high CAPEX and OPEX. Why it applies: processing\_route matches the pox\_biox signal ## How Atlas produces this analysis Minestarters Atlas uses automated extraction to summarize mining announcements, identify reported measurements, and classify supporting evidence. Sentiment reflects the extracted narrative and classification rules; it is an interpretation, not a reported measurement. Evidence quotes and context are provided where available. Missing data, low-confidence results, and review flags indicate limitations. Check the original publisher announcement before relying on an interpretation.