Slide 1: Haile Site Visit
HAILE SITE VISIT April 4, 2024 CARE | RESPECT | INTEGRITY PERFORMANCE | TEAMWORK
Slide 2: Cautionary Statements
CAUTIONARY STATEMENTS Cautionary Notes - Information Purposes Only The information contained in this presentation is provided by OceanaGold Corporation (“OGC”) for informational purposes only and does not constitute an offer to issue or arrange to issue, or the solicitation of an offer to issue, sec
Slide 3: Haile Management Team
3 HAILE MANAGEMENT TEAM Experienced and capable team David Londoño Emily Stephens Joe Lounsbery Kalend Muteb Glenda Parkman Sean Pearce Lee Chapman EVP Manager – Manager – Manager – Manager – Project Director - Manager – COO Americas Mine Open Pit Technical Services Commercial People & Culture Under
Slide 4: Health, Safety & Environment
4 HEALTH, SAFETY & ENVIRONMENT
Slide 5: Safety Performance
SAFETY PERFORMANCE 5 Focus on caring for our people and coaching to a higher standard of safety performance Supervisor Training TRIFR YTD & Proj. Year End 2.50 • Training on the rights and responsibilities of supervisors 2.39 o Federal Laws 2.16 o OceanaGold Values 2.00 o Code of Conduct 1.50 OurSaf
Slide 6: Conservation Stewardship
6 CONSERVATION STEWARDSHIP Contributing to the conservation and improvement of the regional environment outside of our gate In 2024 Haile will be restoring two Flat Creek tributary sites in Upper and Middle Flat Creek which are in the endangered Carolina Heelsplitter Mussels’ home range. The restora
Slide 7: Permitting Success at Haile
7 PERMITTING SUCCESS AT HAILE Strong in-house permitting capabilities and dialogue with regulators December 2022 2024 Received USACE1 permits Received approval for permit No new federal permits are modification for the reserves added needed to deliver LOM for Horseshoe Underground February 21, 2024
Slide 8: Site Overview
a) OCEANAGOLD SITE OVERVIEW
Slide 9: Haile Site Overview
TSF 9 Haile Site Overview Horseshoe Underground Infrastructure • Commenced development September 2022 Process & WTP • Production portal and two ventilation portals Facilities Admin Building • Surface facilities (truck shop, mine office, warehouse, batch plant, compressor station, service water suppl
Slide 10: Accessing Higher Grade Ore at Haile
10 ACCESSING HIGHER GRADE ORE AT HAILE Drives transformation in production & costs Horseshoe Underground Ledbetter Open Pit Palomino Underground • 83 kt of ore mined in 2023 • Increasing access to ore in Q2 2024 • Added 380 koz ounces to reserves • Ramp up to full run rate by mid-2024 • 2024 activit
Slide 11: Mining Operations: Open Pit
11 MINING OPERATIONS OPEN PIT 11
Slide 12: Surface Mining Operations
12 SURFACE MINING OPERATIONS • Primary mining fleet consists of: Surface Mining Physicals – 19 haul trucks (Komatsu 730E-8/10) 2020 2021 2022 2023 2024E1 – 3 Caterpillar 785 Trucks Material Moved Mt 40.3 46.0 41.2 38.0 41.8 – 2 Komatsu PC4000 shovels Material Mined Mt 38.3 43.5 38.1 33.0 36.4 – 1 Ko
Slide 13: Surface Operations – Open Pit Sequencing
13 SURFACE OPERATIONS – OPEN PIT SEQUENCING Total Tonnes Moved by Area 48Mt 50Mt 48Mt 49Mt Admin 42Mt 40Mt 25Mt 21Mt 19Mt 14Mt 6Mt West PAG East PAG 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 Total Ore Tonnes Mined by Area 5.9Mt 5.3Mt 5.0Mt 4.1Mt 3.4Mt 2.4Mt 2.2Mt 2.2Mt 2.1Mt 2.0Mt 1.1Mt
Slide 14: Surface Mining Production & Costs
14 SURFACE MINING PRODUCTION & COSTS LOM Surface Mining Costs (US$/t mined) Surface Mining LOM Tonnes Moved vs. Costs2 60 9.0 Driven by a ~19% increase in component 8.0 usage, and ~17% 50 inflation on costs 7.0 Largely maintenance components +$0.37/gallon in 40 6.0 ~44% increase of diesel price whic
Slide 15: Surface Contact Water Management
15 SURFACE CONTACT WATER MANAGEMENT Significant reduction in contact water with new water treatment plant May 23 Expanded water treatment Contact Water Management: plant on-line • Surface water build-up through periods of increased historical precipitation • In-pit water storage has historically act
Slide 16: Resource Reconciliation
16 RESOURCE RECONCILIATION Positive reconciliation over the last six years • 2023 resource model reconciliation of -5% contained Au ounces driven by mid-year shortfall in Mill Zone pit • Horseshoe UG reconciliation to-date positive1 (+5% tonnes, +2% grade for +7% contained gold) based on first produ
Slide 17: Mining Operations: Underground
17 MINING OPERATIONS UNDERGROUND 17
Slide 18: Underground Operations - Surface Infrastructure
UNDERGROUND OPERATIONS - SURFACE 18 INFRASTRUCTURE
Slide 19: Horseshoe Underground Development
19 HORSESHOE UNDERGROUND DEVELOPMENT First ore in 2023, ramping up to full mining rates by mid 2024 • Accessed via a decline from ~80m below the natural 2023 Underground Mining Physicals surface at Snake Pit Activity Unit Value Ore Mined kt 83 • Two ventilation portals are established on an open be
Slide 20: Underground Life of Mine Plan
20 UNDERGROUND LIFE OF MINE PLAN Horseshoe & Palomino combine to extend the current UG mine life LOM Combined Underground Production Schedule Horseshoe Waste Horsehoe Ore Palomino Waste Palomino Ore Au Grade Ore Tonnes Mined (kt) 1,400 5.00 1,200 4.00 Au Grade (g/t) 1,000 800 3.00 600 2.00 400 1.00
Slide 21: Underground Capital Schedule
21 UNDERGROUND CAPITAL SCHEDULE Capital infrastructure shared between Horseshoe & Palomino • Horseshoe developed to current bottom stoping horizon by 2027 • Current design for Palomino includes ~3,000 meters of capital development o Capital development for underground magazine, shop, and laydown o I
Slide 22: Underground Mining Costs
22 UNDERGROUND MINING COSTS Inflation, consumables & labour resulting in unit cost increases LOM Underground Mining Costs (US$/t mined) Underground Mining LOM Tonnes Moved vs Costs2 +54% Electricity cost UG Waste Mined UG Ore Mined Increases are largely related to With 26% related to 1.4 120 increas
Slide 23: Horseshoe Grade Control Drilling
23 HORSESHOE GRADE CONTROL DRILLING Optimizing the sampling strategy to the orebody Four sample types used: 1) Resource Definition drilling – diamond core, collared from surface and some from UG development. 2) Grade Control drilling – diamond core, horizontal and gently inclined up-holes collared f
Slide 24: Ledbetter Phase 4 Underground Potential
24 LEDBETTER PHASE 4 UNDERGROUND POTENTIAL Evaluating the potential to mine Ledbetter Phase 4 from underground • Current technical report has Ledbetter Phase 4 being mined from surface • Initial study on-going which is evaluating the potential to mine Ledbetter Phase 4 from underground Ledbetter Pha
Slide 25: Process Plant
25 PROCESS PLANT 2525 25
Slide 26: Plant Operations
26 PLANT OPERATIONS Crushing Grinding Control Room Flotation Fine Grinding Carbon in Leach Strip and Refinery Reagents Water Treatment Plant CN Destruct
Slide 27: Processing Physicals
27 PROCESSING PHYSICALS Increased ore understanding has contributed to stabilized recovery across ore types • Conventional flotation and cyanide leaching flow Processing Physicals sheet 2020 2021 2022 2023 2024E1 • Successful debottlenecking upgrade to Gold Production koz 137 190 176 152 214 3.8Mtpa
Slide 28: Ore Hardness
28 ORE HARDNESS Horseshoe Underground ore hardness in-line with expectations • Denver Ore-hardness (quantitative & Ore Hardness at Haile defined by a BWi1) a measure energy • BWi ranges from 9 kWh/t – 15 kWh/t: required for breakage • Mohs Scale (qualitative) showing scratch – Medium soft: Red Hill,
Slide 29: Processing Costs
29 PROCESSING COSTS Cost increases primarily related to inflationary impacts LOM Processing Unit Costs (US$/t milled) LOM Ore Milled vs Processing Unit Cost1 Total Ore Milled Processing Unit Cost ~+25% in reagent ~+61% in Energy of 4.5 20 costs offset by ~8% decrease in reagent which ~54% rise in co
Slide 30: Capital Projects & Continuous Improvement
30 CAPITAL PROJECTS & CONTINUOUS IMPROVEMENT 30 3 0
Slide 31: Continuous Improvement & Cost Savings
31 CONTINUOUS IMPROVEMENT & COST SAVINGS WiredUp is enabling improvement at Haile through Critical Few Initiatives Continuous Improvement Core Success Ingredients 1 Understand our baseline & constraints Alignment on our Critical Few Improvement starts with understanding constraints and aligning 2 Id
Slide 32: Capital Projects
32 CAPITAL PROJECTS LOM Capital Cost Profile1 Capital Projects 200 • West PAG (US$40M): Capacity for current LOM • Stage 1: ~10Mt - planned Q1 2024 180 • Stage 2: ~20Mt - planned Q4 2024 160 • Stage 3: ~40Mt - scheduled for Q4 2026 140 • Tailings Storage Facility (US$93M) 120 • Lift 4 to be complete
Slide 33: Exploration & Drilling
33 LUNCH EXPLORATION & DRILLING 33 33
Slide 34: Underground Exploration Success
34 UNDERGROUND EXPLORATION SUCCESS A A' Reserve: 0.52 Moz @ 4.23 g/t Au2 Horseshoe M&I: 0.67 Moz @ 5.48 g/t Au1,2 Inferred: 0.2 Moz @ 4.1 g/t Au2 Palomino Reserve: 0.38 Moz @ 2.91 g/t Au2 Horseshoe M&I: 0.45 Moz @ 3.10 g/t Au1,2 Inferred: 0.1 Moz @ 2.2 g/t Au2 Extension 16.8 m @ 2.83 g/t Au 7.6 m @
Slide 35: Haile Exploration in 2024
35 HAILE EXPLORATION IN 2024 Resource conversion and new target generation Horseshoe Underground Drilling 2024 Resource Conversion & Growth Portal Portal Portal • $5 million and ~21,600 metres of drilling • Targeting growth at Horseshoe Extension • Targeting conversion of Ledbetter Inferred New Targ
Slide 36: New Exploration Targets
36 NEW EXPLORATION TARGETS Focus on near mine expansion targets Buckskin Horseshoe Ledbetter Conv. HEX Horseshoe Ledbetter Lower Pisces Mill Zone Palomino Palomino Ext.
Slide 37: Appendix
)) OCEANA APPENDIX
Slide 38: Reserves
38 RESERVES As at December 31, 2023 Proven Probable Proven & Probable Area Mt Au g/t Ag g/t Cu % Mt Au g/t Ag g/t Cu % Mt Au g/t Ag g/t Cu % Au Moz Ag Moz Cu Mt Horseshoe Underground 0.10 4.53 2.0 . 3.7 4.23 1.7 . 3.8 4.23 1.7 . 0.52 0.2 . Palomino Underground . . . . 4.0 2.91 2.7 . 4.0 2.91 2.7 . 0
Slide 39: Measured & Indicated Resources
39 MEASURED & INDICATED RESOURCES As at December 31, 2023 Measured Indicated Measured & Indicated Area Mt Au g/t Ag g/t Cu % Mt Au g/t Ag g/t Cu % Mt Au g/t Ag g/t Cu % Au Moz Ag Moz Cu Mt Horseshoe Underground 0.1 5.04 2.0 . 3.7 5.49 2.3 . 3.8 5.48 2.3 . 0.67 0.3 . Palomino Underground . . . . 4.5
Slide 40: Inferred Resources
40 INFERRED RESOURCES As at December 31, 2023 Inferred Area Mt Au g/t Ag g/t Cu % Au Moz Ag Moz Cu Mt Horseshoe Underground 1.8 4.1 2.1 . 0.2 0.13 . Palomino Underground 0.8 2.2 2.0 . 0.1 0.05 . Open Pits 2.8 0.9 . . 0.1 . . Haile Total 5.4 2.2 0.4 0.2 Didipio Underground 12 0.8 1.3 0.3 0.3 0.5 0.03
Slide 41: Technical Disclosure
TECHNICAL DISCLOSURE Qualified Persons Except as otherwise stated herein, David Londono, Executive Vice President, Chief Operating Officer Americas has reviewed and approved the disclosure of all scientific and technical information related to operational matters contained in this presentation. Crai
Slide 42: Contact Details
400 400Burrard Street Burrard #1020 #1020 Street Vancouver, Vancouver,British Columbia British Columbia V6C 3B7 V6C 3B7 Canada Canada T: +1 604 678-4123 +1 604 678-4123 ir@oceanagold.com ir@oceanagold.com oceanagold.com oceanagold.com