Integra Completes Pre-Feasibility Study for DeLamar Project with Average Annual Production of 163,000 oz Au Eq for the First 8 Yrs, and Demonstrates Project Optionality with Phased Development Approach
1050 – 400 Burrard Street Vancouver, British Columbia, Canada V6C 3A6 Email: [email protected]
FOR IMMEDIATE RELEASE TSXV: ITR ; NYSE American: ITRG February 9, 2022 www.integraresources.com
INTEGRA COMPLETES PRE-FEASIBILITY STUDY FOR DELAMAR PROJECT WITH AVERAGE ANNUAL PRODUCTION OF 163,000 OZ AU EQ FOR THE FIRST 8 YRS, AND DEMONSTRATES PROJECT OPTIONALITY WITH PHASED DEVELOPMENT APPROACH
Key Pre-feasibility Study (“PFS”) Highlights:
- The Heap Leach and Mill PFS shows construction in two stages. The combined Stage 1 and 2 contemplates a 35,000 metric tonnes per day (“mtpd”) Heap Leach in Stage 1 that will process Oxide and Mixed ore from both the DeLamar and Florida Mountain Deposits, and a 6,000 mtpd Mill to be constructed in Stage 2 to process Non-Oxide ore:
- Heap Leach and Mill PFS after-tax NPV(5%) of US$412 million and 27% after-tax IRR at US$1,700/ounce (“oz”) Gold (“Au”) and US$21.50/oz Silver (“Ag”) (base case).
- Heap Leach and Mill PFS after-tax NPV(5%) of US$539 million and 33% after-tax IRR at Spot Prices (February 8, 2022) of US$1,826 /oz Au and US$23.00/oz Ag.
- Pre-production capital expenditures (“Capex”) of US$282 million, including contingency of 20% on processing, heap leach and tailing facilities (excluding working capital and assuming mobile mining equipment financing).
- Average annual production of 163,000 oz gold equivalent (“AuEq”)1 for first 8 years with Life of Mine (“LOM”) average annual production of 110,000 oz Au Eq over 16 years.
- LOM site level all-in sustaining costs of (“AISC”) of US$955/oz on an AuEq co-product basis.
- Strong leverage to silver; silver accounts for ~35% of revenue from production.
- Proven and Probable Mineral Reserves of 1.8 M oz Au (at 0.45 g/t Au) and 92.4 M oz Ag (at 23.27 g/t Ag).
- Total LOM Strip Ratio (waste to ore) of 2.21.
- Mill construction will commence in Year 1 at the discretion of the Company and is expected to be financed with internal cash flows. Mill construction in Stage 2 can be pushed out as necessary.
- Stage 1 Heap Leach Only: The Company contemplates beginning the project with Stage 1 Heap Leaching in year 1. Stage 1 includes a 35,000 mtpd Heap Leach of Oxide and Mixed ore. Stage 1 will permit Integra to commence development and operation of the project at lower cash costs and give the Company flexibility to proceed or not proceed with Stage 2 in year 1. Stage 1 offers a robust production profile while requiring significantly lower expansion capital than a combined Heap Leach and Milling development:
- Heap Leach Only (Stage 1) pre-production Capex of US$273 million (excluding working capital and assuming mobile mining equipment financing).
- LOM site level AISC of US$813 /oz on an AuEq co-product basis
- Average annual production of 136,000 oz AuEq over 7 years
1 Gold equivalent = oz Au + (oz Ag ÷ 79.07)
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- Total LOM Strip Ratio (waste to ore): 1.35
- Integra believes that a two-stage development reduces risk because of the greater flexibility to respond to the prevailing economic environment in connection with a decision to pursue Stage 2.
- The PFS includes multiple sustainability-driven initiatives to decrease the environmental footprint of the Project, including:
- Railveyor: The Project’s ore haulage system will utilize Railveyor’s light rail system to haul material between various pits and the processing location, replacing the equivalent of approximately 5 diesel haul trucks. Powered electrically, Railveyor will decrease the Project’s diesel usage and associated direct (Scope 1) greenhouse gas emissions. Downhill portions of the haul will generate power regeneratively, and ancillary benefits will include reduced noise and dust levels, and reduced water consumption for dust mitigation.
- Power Generation: The Company plans to power the Project through an onsite microgrid. A 12megawatt (“MW”) solar array will be installed on the historic tailing impoundment in conjunction with 4.5 MW-hours of batteries and a Liquified Natural Gas (“LNG”) power generation plant to be constructed on site, leased from, and maintained by a third-party provider through a longterm use-based lease agreement. Greenhouse gas emissions from this energy mix will be an estimated 13% lower than the current local utility grid mix. The microgrid levelized cost of energy (“LCOE”) is 63% lower than the local electric utility.
- The incorporation of these plans is not only crucial to lowering the Project’s greenhouse gas emissions, but they also importantly drive stronger economics for the Project, demonstrating how mining projects can benefit economically from taking steps towards sustainability.
- To view a 3D VRIFY presentation of the PFS results, click on the following link:
https://vrify.com/decks/10989?auth=74c8f3c4-fa11-4e7a-ab09-ccab72b99a5e
- To view a video of President and CEO George Salamis discussing the PFS, click on the following link: https://www.youtube.com/watch?v=2xJATH9niCc
Vancouver, British Columbia – Integra Resources Corp. (“Integra” or the “Company”) (TSX-V: ITR; NYSE American: ITRG) is pleased to announce the results of the Pre-feasibility Study (“PFS”) and Mineral Resource and Reserve Statement on its 100% owned DeLamar Project completed by Mine Development Associates, a division of RESPEC of Reno, Nevada, supported by M3 Engineering & Technology Corporation of Chandler, Arizona, McClelland Laboratories, Welsh Hagen Associates, and EM Strategies, a WestLand Resources, Inc, Company, all of Reno, Nevada, Warm Springs Consulting, LLC of Boise, Idaho, and Elbow Creek Engineering of Billings, Montana, for the DeLamar Project (“DeLamar” or the “Project”) located in southwestern Idaho.
George Salamis, Integra Resources President and CEO reports: “The completion of the DeLamar Prefeasibility study is a crowning achievement for the Company, representing the culmination of two years of work by the Integra team and its various consultants. Following on from the success of the 2019 preliminary economic assessment, this PFS is a materially different and larger scale Project, both in Heap Leaching and Milling, relative to the PEA. Despite inflationary pressure currently overhanging the mining industry from a capital and operating cost perspective, the Project continues to demonstrate strong positive economics and a high degree of optionality in terms of the scale, mining/processing scope and capital cost of gold/silver mines to be built at the Project. The two-stage Project contemplates a larger
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scale open pit mining scenario that combines Heap Leaching and Milling to achieve an average production level of 163,000 AuEq ozs per annum for the first 8 years, a mine life of 16 years, life of mine site level AISC of $955/oz (co-product basis) and with a clear path to future Non-Oxide processing enhancements and resource growth upside.” Mr. Salamis continues, “the staged approach to development also means that the Company starts production with Heap Leach only that can be developed with far lower capital and operating cost requirements, capable of producing an average of 136,000 AuEq ozs per annum at a site level AISC $813/oz (co-product basis). We believe that in an inflationary environment, such as the one that our shareholders and stakeholders are currently experiencing, having a multi-phase development stage is critically important, and demonstrates maximum flexibility and transparency. This study also outlines the potential for significant upside opportunities at the DeLamar Project, including increased gold and silver recoveries in the Non-Oxide ore through the use of Albion processing methods, a process that has much lower capital costs than traditional Oxidation plants and has yielded promising results in recent test work. Additionally, this study does not incorporate any of the high-grade gold-silver potential below the Florida Mountain resource envelope.”
Integra will host a call on February 10, 2022, at 8am PST/11am EST. To register for the webinar, click on the following link: https://us02web.zoom.us/webinar/register/WN_VUvizkuaSlykvDQGzaSWaQ
1. DeLamar Project Global (DeLamar + Florida Mountain) Gold and Silver Reserves
Mineral Resources
Table 1 shows the updated Mineral Resource estimate included in the PFS.
Table 1: Mineral Resource Estimate
Notes:
| (1) All estimates of Mineral Resources have been prepared in accordance with | NI 43-101. | ||
| (2) Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. | |||
| (3) Mineral Resources are reported inclusive of Mineral Reserves. | |||
| (4) Michael Gustin, MDA a division of RESPEC of Reno, Nevada, is a Qualified Person | as defined in NI 43-101, is | responsible for reporting | |
| Mineral Resources for the DeLamar Project. Mr. Gustin is independent of the Company. | |||
| (5) The DeLamar and Florida Mountain Deposit Mineral Resources have been constrained to lie within optimized pit shells created using | |||
| metal prices of US$1,800/ounce of gold and US $21/ounce of silver. |
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(6) Oxidize and Mixed Mineral Resources are reported at a 0.17 g AuEq/t cut-off in consideration of potential open-pit mining and Heap Leach processing. Non-Oxide Mineral Resources are reported at a 0.3 g AuEq/t cut-off at DeLamar in consideration of potential open pit mining and grinding, flotation, ultra-fine regrind of concentrates, and Albion cyanide-leach processing of the reground concentrates. Non-Oxide Mineral Resources at Florida Mountain are reported at a 0.2 g AuEq/t cut-off in consideration of potential open pit mining and grinding, flotation, ultra-fine regrind of concentrates, and agitated cyanide-leaching for the Non-Oxide materials.
(7) Additional inputs for the pit-optimizations include: Mining - US$2.20/tonne mined; Heap Leaching - US$2.75/t for Oxide materials, US$3.75/t for Mixed materials at DeLamar and US$3.50/t at Florida Mountain; Non-Oxide Processing - US$15.65/t at DeLamar and US$9.45/t at Florida Mountain; G&A - US$0.40/t processed by Heap Leaching and $0.50/t for processing of Non-Oxide materials; Heap Leach Gold Recoveries – 85% / 45% for Au / Ag Oxide and 80% / 40% for Mixed at DeLamar, 90% / 65% for Au / Ag Oxide and 85% / 55% for Mixed at Florida Mountain; and Non Oxide Recoveries - 78% / 78% for Au / Ag at Glen Silver area of DeLamar, 87% / 87% for all other DeLamar areas, and 95% / 92% for Au / Ag at Florida Mountain.
(8) Gold equivalent grades are calculated using the formula g/t AuEq = g/t Au + (g/t Ag/Factor), with the factor reflecting the metal recoveries by oxidation and metal prices provided above. The gold equivalent grades were used solely in the application of the resource cut-offs.
(9) The effective date of the Mineral Resource estimate is March 1, 2021.
(10) Rounding as required by reporting guidelines may result in apparent discrepancies between tonnes, grades, and contained metal content.
(11) The estimate of Mineral Resources may be materially affected by geology, environment, permitting, legal, title, taxation, sociopolitical, marketing, or other relevant issues.
Mineral Reserves
Table 3 shows the proven and probable reserves for both Heap Leach and Mill ore by deposit. The reserves were estimated using block value calculated based on metal price and recoveries by area and oxidation. The cost to process the material was then used as a cut-off grade. The metal prices used to calculate the block values were $1,600 per ounce gold and $21.00 per ounce silver, though the final cashflow model used $1,700 per ounce gold and $21.50 per ounce silver. The block value calculation equation is shown in Equation 1 in the footnotes. The block value was calculated for both gold and silver and then each was added together to provide an overall value for each block.
Recoveries used for the block value calculations are shown in Table 2 and were provided by Jack McPartland a member of MMSA, with a special expertise in metallurgy/processing, of McClelland Laboratories of Reno, Nevada. The recoveries for Florida Mountain Non-Oxide material used grade dependent equations shown in Equations 2 and 3 in the footnotes for gold and silver respectively.
Table 2 – Reserve Gold and Silver Recoveries
Table 3: Mineral Reserves
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| Florida Mountain | Leach | Mill | Total | ||||||
| Proven | Probable | P&P | Proven | Probable | P&P | Proven | Probable | P&P | |
| K Tonnes g Au/t K Ozs Au g Ag/t K Ozs Ag Block Value | 5,789 0.50 94 16.02 2,981 $ 24.75 | 39,919 0.42 541 10.73 13,768 $ 20.18 | 45,708 0.43 635 11.40 16,749 $ 20.76 | 1,306 0.48 20 12.24 514 $ 26.72 | 9,249 0.54 160 12.27 3,648 $ 29.37 | 10,555 0.53 180 12.26 4,162 $ 29.04 | 7,095 0.50 114 15.32 3,495 25.12 | 49,168 0.44 701 11.02 17,417 21.91 | 56,263 0.45 815 11.56 20,911 $ 22.31 |
DeLamar Deposit
| K Tonnes | 5,247 | 41,285 | 46,533 | 6,016 | 14,672 | 20,688 | 11,263 | 55,958 | 67,221 |
| g Au/t | 0.41 | 0.35 | 0.36 | 0.69 | 0.63 | 0.65 | 0.56 | 0.43 | 0.45 |
| K Ozs Au | 69 | 471 | 540 | 133 | 299 | 432 | 202 | 770 | 972 |
| g Ag/t | 31.24 | 22.07 | 23.10 | 62.03 | 52.86 | 55.52 | 47.69 | 30.14 | 33.08 |
| K Ozs Ag | 5,270 | 29,290 | 34,560 | 11,998 | 24,934 | 36,931 | 17,268 | 54,223 | 71,491 |
Block Value $ 19.83 $ 16.19 $ 16.60 $ 42.07 $ 36.62 $ 38.20 31.71 21.54 $ 23.25
Total DeLamar Project
| K Tonnes | 11,036 | 81,205 | 92,241 | 7,321 | 23,921 | 31,243 | 18,358 105,126 123,483 | ||
| g Au/t | 0.46 | 0.39 | 0.40 | 0.65 | 0.60 | 0.61 | 0.54 | 0.44 | 0.45 |
| K Ozs Au | 163 | 1,012 | 1,175 | 153 | 459 | 612 | 316 | 1,471 | 1,787 |
| g Ag/t | 23.25 | 16.49 | 17.30 | 53.15 | 37.16 | 40.91 | 35.18 | 21.20 | 23.27 |
| K Ozs Ag | 8,251 | 43,058 | 51,310 | 12,511 | 28,582 | 41,093 | 20,763 | 71,640 | 92,403 |
| Block Value | 22.41 | 18.15 $ | |||||||
| 18.66 | 39.33 | 33.81 $ | |||||||
| 35.11 | 29.16 | 21.71 $ |
22.82
Notes:
| (1) All estimates of Mineral Reserves have been prepared in accordance with | National Instrument 43 - 101 – Standards of Disclosure for | |||
| Mineral Projects (“NI 43-101”). | ||||
| (2) Thomas L. Dyer, PE, MDA a division of RESPEC of Reno, Nevada, is a Qualified Person | as defined in NI 43-101, is | responsible for reporting | ||
| Proven and Probable Mineral Reserves for the DeLamar Project. Mr. Dyer is independent of the Company. | ||||
| (3) Mineral Reserves are based on prices of $1,650 per ounce Au and $21.00 per ounce Ag. The reserves were defined based on pit designs | ||||
| that were created to follow optimized pit shells created in Whittle. Pit designs followed pit slow recommendations provided by RESPEC. | ||||
| (4) Reserves are reported using block value cut-off grades representing the cost of processing: |
Florida Mountain Oxide Leach cut-off grade of used is $3.55/t.
Florida Mountain Mixed Leach cut-off grade of used is $4.20/t.
Florida Mountain Non-Oxide Mill cut-off grade of used is $10.35/t.
DeLamar Oxide Leach cut-off grade of used is $3.65/t DeLamar Mixed Leach cut-off grade of used is $4.65/t.
DeLamar Non-Oxide Mill cut-off grade of used is $15.00/t.
(5) The Mineral Reserves point of reference is the point where is material is fed into the crusher.
(6) The effective date of the Mineral Reserves estimate is January 24, 2022.
(7) All ounces reported herein represent troy ounces; “g Au/t” represents grams of gold per tonne and “g Ag/t” represents grams of silver per tonne.
(8) Columns may not sum due to rounding.
(9) The estimate of Mineral Reserves may be materially affected by geology, environment, permitting, legal, title, taxation, sociopolitical, marketing, or other relevant issues
(10) Energy prices of US$2.50 per gallon of diesel and US$0.065 per kWh were used.
(11) Additional supporting details regarding the information in this news release will be provided in the pre-feasibility study to be available on SEDAR within 45 days of this news release.
(12) Additional supporting details regarding the information in this news release will be provided in the pre-feasibility study to be available on SEDAR within 45 days of this news release.
𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵= 𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑔𝑔/𝑡𝑡∗𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃
(13) Equation 1: Block value calculation:
31.10348 ∗𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅𝑅∗(1 −𝑟𝑟𝑟𝑟𝑟𝑟%)
(14) Equation 2: Florida Mountain Non-Oxide Gold Recovery (Where the maximum gold recovery = 87%)
(15) Equation 3: Florida Mountain Non-Oxide Silver Recovery (Where the maximum silver recovery = 77%)
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𝐴𝐴𝐴𝐴𝑟𝑟𝑟𝑟𝑟𝑟= � 100 �∗0.88 13.021∗ln�𝐴𝐴𝐴𝐴𝑔𝑔𝑔𝑔𝑔𝑔�+48.447 The resources are supported by 258,318 meters of drilling, 131,271 meters at the DeLamar Deposit and 127,047 meters at the Florida Mountain Deposit. This drilling is a combination of historical drilling and drilling completed by Integra Resources.
| 2. Stage 1 and 2 Development: PFS Overview - Heap Leach and Mill | |
| The PFS contemplates an open pit mine with on-site treatment of Oxide and Mixed ores via a 35,000 mtpd | |
| Heap Leach facility at 80% passing 12.7 mm (0.5 inch), and treatment of a portion of the Non-Oxide | |
| mineralization through a 6,000 mtpd Mill utilizing conventional grind, flotation, re-grinding and | |
| cyanidation of the concentrate. In year 1, Heap Leaching of Florida Mountain ore will commence, with | |
| Mill construction beginning in year 1 and production starting in year 3. In year 2, Oxide and Mixed ore | |
| from the DeLamar Deposit will be mined with the Non-Oxide ore being accessed from the DeLamar and | |
| Florida Mountain Deposits starting in year 3. In total, the Project will process 123,483,000 tonnes of ore | |
| over a 16-year mine life producing 1,154,431 oz Au and 49,995,640 oz Ag (1,786,729 oz AuEq). The strip | |
| ratio over LOM, waste-to-ore, is 2.21. | |
| The PFS is derived from the Company’s pit-constrained Mineral Reserve estimate with an effective date | |
| of January 24, 2022 and does not include results from drilling completed in 2021. The effective date of | |
| the PFS is January 24, 2022 and a technical report will be filed on the Company’s website and SEDAR within | |
| 45 days of this news release. | |
| DeLamar Project Heap Leach and Mill PFS Highlights: |
- Year 1 to Year 8 average annual production of 121,000 0 oz Au and 3.3 million oz Ag (163,000 oz AuEq).
- LOM (Year 1 to Year 16) average annual production of 71,000 oz Au and 3.1 million oz Ag (110,000 oz AuEq).
- After-tax IRR of 27%.
- After-tax NPV (5%) of US$412 million.
- US$695 million after-tax LOM cumulative cash flow.
- 35,000 mtpd open pit/Heap Leach production rate with an initial mine life of 16 years, sourcing Oxide and Mixed ore from both the Florida Mountain and DeLamar Deposits.
- 6,000 mtpd Mill, commencing in Year 3, primarily sourcing Non-Oxide ore from the Florida Mountain Deposit and then from the DeLamar Deposit over a 15-year period.
- LOM site level AISC of US$547/oz net of silver by-product or US$955/oz on an Au Eq co-product basis.
- LOM strip ratio of 2.21 (Waste: Ore).
- Low pre-production Capex of US$282 million (excluding working capital/bonding; assuming mobile equipment financing).
- LOM capital expenditures (pre-production + expansion/sustaining capital) of US$576 million
- After-tax payback period of 3.3 years.
- Mill expansion capital expected to be financed with internal cash flows.
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Table 4: DeLamar Project Heap Leach and Mill PFS Detailed Assumptions:
| Contained Metals | |
|---|---|
| Contained Gold ounces (000's oz) | 1,787 |
| Contained Silver ounces (000's oz) | 92,403 |
| Contained AuEq ounces (000's oz) | 2,955 |
| Mining | |
| Mine Life | 16 years |
| Strip Ratio (Waste: Ore) | 2.21 |
| Total Tonnage Mined (000's mt) | 396,701 |
| Total Ore Mined (000's mt) | 123,483 |
| Processing | |
| Processing Throughput: Heap-Leaching/Milling | 35,000 mtpd / 6,000 mtpd |
| Average Diluted Gold Grade (g/t) - HL | 0.40 |
| Average Diluted Silver Grade (g/t) - HL | 17.30 |
| Average Diluted AuEq Grade (g/t) - HL | 0.62 |
| Average Diluted Gold Grade (g/t) - Milling | 0.61 |
| Average Diluted Silver Grade (g/t) - Milling | 40.91 |
| Average Diluted AuEq Grade (g/t) - Milling | 1.13 |
| Production | |
| Heap Leach Recovery | |
| Florida Heap Leach Recovery (%) - Gold | 76% |
| DeLamar Heap Leach Recovery (%) - Gold | 66% |
| Florida Heap Leach Recovery (%) - Silver | 47% |
| DeLamar Heap Leach Recovery (%) - Silver | 32% |
| Mill Recovery | |
| Florida Mill Recovery (%) - Gold | 83% |
| DeLamar Mill Recovery (%) - Gold | 37% |
| Florida Mill Recovery (%) - Silver | 72% |
| DeLamar Mill Recovery (%) - Silver | 75% |
| Payable Metals | |
| LOM Payable Gold ounces (000's oz) | 1,149 |
| LOM Payable Silver ounces (000's oz) | 49,746 |
| LOM Payable AuEq ounces (000's oz) | 1,778 |
| Years 1-8 Avg Annual Production - Gold (000's oz) | 121 |
| Years 1-8 Avg Annual Production - Silver (000's oz) | 3,312 |
| Years 1-8 Avg Annual Production - AuEq (000's oz) | 163 |
| Years 1-16 Avg. Annual Production - Gold (000's oz) | 71 |
| Years 1-16 Avg. Annual Production - Silver (000's oz) | 3,085 |
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| Years 1-16 Avg. Annual Production - AuEq (000's oz) | 110 | ||
| Costs per Tonne | |||
| Mining Costs ($/t mined) | $1.89 | ||
| Mining Costs ($/t processed) | $6.08 | ||
| Processing Costs ($/t heap leached) – HL | $3.74 | ||
| Processing Costs ($/t milled) – Milling | $12.57 | ||
| Processing Costs ($/t processed) – Combined | $5.99 | ||
| G&A Costs ($/t processed) | $0.86 | ||
| Total Site Operating Cost ($/t processed) | $12.92 | ||
| Cash Costs1 | |||
| LOM Cash Cost ($/oz) Au, net-of-silver by-product | $497 | ||
| LOM Cash Cost ($/oz) AuEq, co-product | $923 | ||
| LOM Site Level AISC ($/oz) Au, net-of-silver by-product | $547 | ||
| LOM Site Level AISC ($/oz) AuEq, co-product | $955 | ||
| Capital Expenditures | |||
| Initial Capital Expenditures ($ MM)2 | $281.9 | ||
| Working Capital / Reclamation Bond ($ MM)3 | $25.6 | ||
| Non-Ox Mill (Plant & Tailing LOM) ($ MM) | $194.6 | ||
| Other Sustaining Capex / Equipment Financing Pmts ($ MM) | $99.9 | ||
| Reclamation Cost ($ MM) | $30.8 | ||
| Salvage Value ($ MM) | ($23.7) | ||
| Economic Assumptions | |||
| Gold Price | $1,700 | ||
| Silver Price | $21.50 | ||
| Exchange Rate (US$/C$) | 1.25 | ||
| Economics4 | |||
| After-Tax IRR | 27% | ||
| NPV (5%) (US$ million) | $412.3 | ||
| NPV (5%) (C$ million) | $515.4 | ||
| Payback period | 3.33 | ||
| Average Annual net free cash flow (US$ million) | $60.2 | ||
| LOM net after-tax free cash flow (US$ million) | $695.0 | ||
| Notes: | |||
| (1) Cash costs and AISC are non-GAAP measures. See reference below regarding non-GAAP measures. | |||
| (2) Assumes equipment financing for primary equipment only (10% cash deposit) | |||
| (3) Working capital and reclamation bonding returned in year 17. Reclamation bond assumes 20% cash collateral. | |||
| (4) Free cash flow is a non-GAAP measure. See references below regarding non-GAAP measures. |
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Gold Equivalent Production Profile (breakdown by processing method):
Au Eq Production Profile (by Processing Method)
250,000
200,000
150,000
100,000
50,000
Yr1 Yr2 Yr3 Yr4 Yr5 Yr6 Yr7 Yr8 Yr9 Yr10 Yr11 Yr12 Yr13 Yr14 Yr15 Yr16 Year
Au Eq Production - Heap Leach Au Eq Production - Mill
Gold Equivalent Production Profile (breakdown by metals):
Au Eq Production Profile (by Metals)
250,000
200,000
150,000
100,000
50,000
Yr1 Yr2 Yr3 Yr4 Yr5 Yr6 Yr7 Yr8 Yr9 Yr10 Yr11 Yr12 Yr13 Yr14 Yr15 Yr16 Year
Au Production Ag Production (Au Eq)
Sensitivities to Gold and Silver Prices:
The table below illustrates a range of metal pricing scenarios on an after-tax basis to evaluate the economics of the Project. As shown, the Project remains very viable in the downside commodity price scenario and as well, is extremely robust in the upside case.
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| $/oz Au | $/oz Ag | NPV (5%) | NPV (8%) | NPV (10%) | IRR | Payback |
|---|---|---|---|---|---|---|
| $ 1,500 | $ 18.97 | $203.4 | $127.4 | $87.9 | 16% | 4.26 |
| $ 1,550 | $ 19.60 | $255.8 | $171.2 | $127.1 | 19% | 3.92 |
| $ 1,600 | $ 20.24 | $308.5 | $215.1 | $166.3 | 22% | 3.69 |
| $ 1,650 | $ 20.87 | $360.3 | $258.1 | $204.7 | 25% | 3.50 |
| $ 1,700 | $ 21.50 | $412.3 | $301.5 | $243.4 | 27% | 3.33 |
| $ 1,750 | $ 22.13 | $464.0 | $344.5 | $281.8 | 30% | 3.17 |
| $ 1,800 | $ 22.76 | $514.8 | $386.7 | $319.4 | 32% | 3.03 |
| $ 1,850 | $ 23.40 | $565.5 | $428.8 | $357.0 | 34% | 2.92 |
| $ 1,900 | $ 24.03 | $616.3 | $471.0 | $394.6 | 37% | 2.82 |
| $ 1,950 | $ 24.66 | $667.1 | $513.3 | $432.4 | 39% | 2.72 |
| $ 2,000 | $ 25.29 | $718.1 | $555.7 | $470.2 | 41% | 2.63 |
| Operations | ||||||
| Over 300 mining, processing, maintenance, and general administrative people will be employed directly | ||||||
| by the Project in peak years making it a significant contributor to the economy of Owyhee County, located | ||||||
| in southwest Idaho. The PFS does not contemplate the need for an expanded mining camp facility during | ||||||
| development and operation as it is expected that a significant portion of the employee base will be hired | ||||||
| from Owyhee County and Malheur County, Oregon. | ||||||
| Mining | ||||||
| The Company expects to finance the mining equipment for the operation. The primary fleet consists of | ||||||
| two 23 m3 hydraulic shovels, sixteen 136 tonne haul trucks, five production drills and ancillary support | ||||||
| equipment. In addition, the Railveyor system will provide the majority of ore hauling from pit to | ||||||
| processing, replacing approximately 5 haul trucks. | ||||||
| Metallurgy |
The process flowsheets for both the Heap Leach and Milling circuits have been designed around historical test work from the 2019 PEA and metallurgical studies completed in 2020 and 2021.
The most recent program was designed to confirm and optimize the 2019 PEA flowsheets and incorporate the DeLamar Non-Oxide mineralization. The work was completed by McClelland Laboratories, Inc. (MLI) in Sparks, Nevada.
The Florida Mountain and DeLamar Deposits are distinctly different metallurgically, both in the Heap Leach ores (Oxide and Mixed) and the Mill ore (Non-Oxide). Separate mirrored metallurgical test programs were run for Heap and Mill feeds from both ore bodies.
Heap Leach Test Work The Florida Mountain Heap Leach testing comprised of 47 variability Bottle Roll Tests ("BRTs”) plus 7 additional BRTs on Non-Oxidized material, while 38 composites were created for DeLamar. These composites were selected to cover the deposit spatially, by depth, by grade, and by lithology. In general, six meter (20 ft) intervals were used to mimic the expected bench height. These tests showed little variability for the Florida Mountain Heap Leach feed; while the DeLamar Heap Leach ores showed significant variability by zone.
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This Column Leach Test (“CLT”) program included 11 composites for Florida Mountain and 12 for DeLamar selected based on results from the BRT variability program. Kinetic BRTs were performed on each composite. Multiple composites from each deposit were run at both 50mm (2 inches) and 12.7mm (0.5 inch), and a Florida Mountain Mixed master composite was crushed to 9.5mm (0.375 inch) using a single pass through a high-pressure grinding rolls (HPGR), and column leached for size sensitivity analysis.
Economic analysis of the results from these programs, in conjunction with the PEA metallurgical testing, yielded a 12.7mm (0.5 inch) crush size selection. This is down from 50mm (2 inches) for Florida Mountain in the PEA, but confirmed the PEA crush size for DeLamar. Load-permeability testing on 12.7mm (0.5 inch) column residues resulted in no agglomeration requirements for Florida Mountain and agglomeration for 45% of DeLamar ore.
Milling Test Work Mill testing was completed on seven composites from Florida Mountain and twelve composites from DeLamar. Kinetic mill/cyanidation whole ore leach BRT’s were completed on each Florida Mountain composite at 1.7mm (10 Mesh (M)) and 75µm (200M). DeLamar and Florida Mountain composites were also used for flotation variability testing.
Florida Mountain master composites were created for whole ore flotation versus gravity concentration with flotation of the gravity tailing comparison at various grind sizes. Flotation tailing leach tests were also completed on these composites. Rougher flotation at a P80 of 150µm gave equivalent results to gravity concentration with flotation of the tailing. Finer grind sizes yielded no appreciable flotation recovery improvements for either ore body. Leaching of the flotation tailing proved uneconomic due largely to the very high flotation recoveries of gold and silver to the concentrate. Flotation optimization on DeLamar master composites confirmed the grind size selection of 150µm.
Overall master composites were created for bulk flotation to produce concentrate for leach testing and optimization, primarily regrind size. A regrind target P80 of 20µm was selected for both deposits. Solid liquid separation testing was completed on the Florida Mountain flotation tailing and is planned for the concentrate leach tailing, and both flotation tailing and concentrate leach tailing from DeLamar. Cyanide Detox testing is also planned for the concentrate leach tailing streams.
All Florida Mountain composites and two DeLamar composites underwent Bond Ball Mill Work Index and Abrasion Index testing. Crusher Work Index testing was completed on various composites.
Two composite flotation concentrate samples from DeLamar were sent for scoping level Albion Process testing at SGS Lakefield. The proprietary Albion Process employs ultra-fine grinding + atmospheric oxidation followed by agitated cyanidation. Results showed significant gold and silver recovery improvements from the concentrates compared to ultra-fine regrind-cyanide leach. Flotation with Albion processing of the flotation concentrate indicated over 80% total recovery for both gold and silver from Sullivan Gulch material and over 70% total recovery for both gold and silver from the Glen Silver material. Future test work is planned for further investigation into the Albion Process.
Minerology Head splits of certain composites were submitted to Vidence, Inc. (“Vidence”) in Burnaby, British Columbia, for mineralogical and textural characterization. Vidence uses QEMSCAN technology for modal mineralogy and texture. More detailed gold and silver deportment QEMSCAN type mineralogical analyses
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and diagnostic lech tests were conducted on select (5) DeLamar Non-Oxide composites by BV Minerals, in Richmond, British Columbia.
Process Design
Heap Leaching Process Despite the differences between the 2 deposits, the most economic processing of each requires essentially the same flowsheets.
Crushing will be done in three stages with a primary gyratory crusher, one secondary crusher in open circuit fed from the Heap Leach Coarse Ore stockpile via three reclaim feeders, and two closed circuit tertiary cone crushers to a nominal P80 of 12.7mm (0.5 inch). The primary crusher is sized to handle both Heap Leach and Mill throughputs.
Ore will be placed on the pads primarily by overland conveying, grasshopper conveyors, and a radial stacker. An agglomeration drum will be added to the process for year 2 production when DeLamar ores are introduced. There are three phases of pad construction, starting on the Jacob’s Ridge Pad, then building out 2 phases of the Valley Pad. Each will have dedicated pregnant solution collection ponds and event storage.
Recovery of gold and silver will be via Merrill-Crowe, and an onsite laboratory will support Heap Leach and Milling operations.
Milling Process The Mill circuit will utilize the same primary crusher as the Heap Leach circuit. Crushed ore from the Non- Oxide Coarse Ore Stockpile with be delivered via two reclaim feeders to a 6.7m x 4.6m (22ft x 15ft) 2985 kW (4000 HP) SAG Mill with pebble recycle. SAG screen undersize will report to a 4.6m x 9.1m (15ft x 30ft) 2985 kW (4000 HP) Ball Mill in closed circuit with cyclones to produce a P80 of 150µm for rougher flotation. Concentrate will be reground to a P80 of 20µm via a 1120 kW (1500 HP) IsaMill.
Concentrate will be leached in 6 agitated tanks utilizing gravity flow with a residence time of 24 hours. Leached slurry will then report to a tank and cyclone CCD circuit for pregnant solution separation, which will report to the Heap Leach Merrill-Crowe circuit.
Non-cyanide contacted flotation tailing will be stored in a separate facility from the leached concentrate. After detoxification, concentrate leach tailing will be blended at a 1:1 ratio with coarser flotation tailing to aid in settling. The concentrate leach tailing storage facility will also act as emergency heap leach solution storage.
To view the Heap Leach Flow Sheet, click on the following link:
https://integraresources.com/site/assets/files/2572/heap_leach_fs_pfs.pdf To view the Mill Flow Sheet, click on the following link:
https://integraresources.com/site/assets/files/2572/mill_fs_pfs.pdf To view a Project site map, click on the following link:
https://integraresources.com/site/assets/files/2572/site_map_pfs.pdf