TECHNICAL REPORT SUMMARY OF
THE SIBANYE-STILLWATER US PGM OPERATIONS
SITUATED IN THE
MONTANA, UNITED STATES
Report Date: 13 December 2023
Effective Date: 31 December 2021
Prepared by:
Qualified Persons at Sibanye-Stillwater US PGM Operations
Important Notices
Description of Amendments to Previously Filed Technical Report Summary
This Technical Report Summary (TRS) for the US PGM Operations of Sibanye-Stillwater Limited (Sibanye- Stillwater) (the Sibanye-StillwaterUS PGM Operations), dated 13 December 2023, serves as an amendment to the TRS prepared by the Qualified Persons at Sibanye-Stillwater for the fiscal year ended 31 December 2021, effective 31 December 2021, which was filed as Exhibit 96.1 to Sibanye- Stillwater's 2021 annual report filed on Form 20-F on 22 April 2022 (the Original 2021 Sibanye-StillwaterUS PGM Operations TRS) and incorporated by reference into Sibanye-Stillwater's 2022 annual report filed on Form 20-F on 24 April 2023.
This TRS was prepared by the Qualified Persons at Sibanye-Stillwater following the receipt of comment letters by Sibanye-Stillwater and associated dialogue with the staff (the Staff) of the United States Securities and Exchange Commission (the SEC) regarding information in the Original 2021 Sibanye- Stillwater US PGM Operations TRS. While this TRS incorporates certain changes to the Original 2021 Sibanye-Stillwater US PGM Operations TRS, it maintains an effective date of 31 December 2021 with regard to assumptions and the knowledge of the Qualified Persons at Sibanye-Stillwater. This TRS revises the following information in the Original 2021 Sibanye-Stillwater US PGM Operations TRS as a result of the comments received from the Staff:
- Revisions to the abridged cash flow results table on page [253] (Table 63) to include the particularized disclosure requirements of Item 601(b)(96)(iii)(B)(19) of Regulation S-K in one table, including annual production for the life of the project and the associated revenue, operating and capital costs, taxes, and royalties.
ii
Table of Contents | |
EXECUTIVE SUMMARY | 1 |
Introduction | 1 |
Property Description, Mineral Rights and Ownership | 1 |
Geology and Mineralisation | 2 |
Exploration Status, Development and Operations and Mineral Resource Estimates | 2 |
Mining Methods, Ore Processing, Infrastructure and Mineral Reserve Estimates | 4 |
Capital and Operating Cost Estimates and Economic Analysis | 7 |
Permitting Requirements | 8 |
Conclusions and Recommendations | 8 |
INTRODUCTION | 9 |
Registrant | 9 |
Compliance | 9 |
Terms of Reference and Purpose of the Technical Report | 9 |
Sources of Information | 10 |
Site Inspection by Qualified Persons | 11 |
Units, Currencies and Survey Coordinate System | 11 |
RELIANCE ON INFORMATION PROVIDED BY REGISTRANT | 12 |
PROPERTY DESCRIPTION | 14 |
Location and Operations Overview | 14 |
Mineral Title | 15 |
Title Overview | 15 |
Title and Tenure Held | 15 |
Title and Tenure Conditions and Compliance | 17 |
Surface Rights and Servitudes | 18 |
Royalties | 20 |
Legal Proceedings and Significant Encumbrances to the Property | 20 |
ACCESSIBILITY, CLIMATE, LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY | 22 |
Topography and Elevation | 22 |
Stillwater Mine and the Hertzler Tailing Storage Facility | 22 |
East Boulder Mine | 22 |
Fauna and Flora | 22 |
Access, Towns and Regional Infrastructure | 23 |
Climate | 23 |
Infrastructure and Bulk Service Supplies | 24 |
iii
Personnel Sources | 25 |
HISTORY | 26 |
Ownership History | 26 |
Previous Exploration and Mine Development | 27 |
Previous Exploration | 27 |
Mine Development | 28 |
Plant, Property and Equipment | 29 |
ADJACENT PROPERTIES | 31 |
GEOLOGICAL SETTING, MINERALISATION AND DEPOSIT | 32 |
Regional Geology | 32 |
Local and Property Geology | 35 |
Local Stratigraphy | 35 |
J-M Reef Mineralisation | 37 |
EXPLORATION | 44 |
Data Acquisition Overview | 44 |
Gravity Surveys | 44 |
Aeromagnetic Surveys | 44 |
Topographic Surveys | 45 |
Exploration and Mineral Resource Evaluation Drilling | 45 |
Drilling | 45 |
Core Logging and Reef Delineation | 50 |
Survey Data | 50 |
Density Determination | 52 |
Underground Mapping | 52 |
Hydrogeological Drilling and Testwork | 53 |
Stillwater Mine | 53 |
East Boulder Mine | 56 |
Geotechnical Data, Testing and Analysis | 58 |
Geotechnical Characterisation | 58 |
Geotechnical Testwork and Data Collection | 58 |
Geotechnical Results and Interpretation | 60 |
SAMPLE PREPARATION, ANALYSES AND SECURITY | 62 |
Sampling Governance and Quality Assurance | 62 |
Reef Sampling | 63 |
Sample Preparation and Analysis | 63 |
Laboratory | 63 |
iv
Sample Preparation and Analysis | 64 |
Analytical Quality Control | 65 |
Nature and Extent of Quality Control Procedures | 65 |
Quality Control Results | 66 |
DATA VERIFICATION | 71 |
Data Storage and Database Management | 71 |
Database Verification | 71 |
MINERAL PROCESSING AND METALLURGICAL TESTING | 73 |
Metallurgical Testwork and Amenability | 73 |
Deleterious Elements | 73 |
MINERAL RESOURCE ESTIMATES | 74 |
Background | 74 |
Geological Modelling and Interpretation | 74 |
Zone Picking and Evaluation Cut Determination | 74 |
Data Processing and Analysis | 75 |
Structural Modelling and Geological Loss Determination | 81 |
Geological Interpretation and Wireframe Modelling | 81 |
Block Modelling | 86 |
Grade and Tonnage Estimation | 86 |
Grade and Thickness Estimation | 86 |
Block Model Validation | 90 |
Tonnage Estimation | 92 |
Mineral Resource Classification | 92 |
Cut-off Grades, Technical Factors and Reasonable Prospects for Economic Extraction | 93 |
Prospects for Eventual Economic Extraction Assessment | 93 |
Cut-off Grades and Minimum Mining Width | 94 |
Mineral Resource Estimates | 96 |
MINERAL RESERVE ESTIMATES | 98 |
Mineral Resource to Mine Reserve Conversion Methodology | 98 |
Mineral Resources Available for Conversion | 98 |
Mineral Reserve Estimation Methodology | 98 |
Point of Reference | 100 |
Cut-off Grades | 100 |
Mineral Reserve Classification Criteria | 101 |
Mineral Reserve Estimates | 104 |
Risk Assessments | 105 |
v
MINING METHODS | 107 |
Introduction | 107 |
Mine Design | 107 |
Mining Method Rationale | 107 |
Ramp and Fill Method | 108 |
Captive Cut and Fill Method | 109 |
Sub-level Extraction and Sub-level Development | 109 |
Transverse Long Hole Stoping | 110 |
Stope Extraction Ratios | 111 |
Hydrogeological Model | 111 |
Stillwater Mine | 111 |
East Boulder Mine | 112 |
Geotechnical Model | 112 |
Geotechnical Characterisation | 112 |
Support Design | 113 |
Surface and Subsidence Control | 114 |
Backfill | 114 |
Stillwater Mine Operations | 115 |
Background | 115 |
Key Operational Infrastructure | 116 |
Mine Layout | 116 |
East Boulder Mine Operations | 117 |
Background | 117 |
Key Operational Infrastructure | 117 |
Mine Layout | 118 |
Life of Mine Planning and Budgeting | 120 |
Introduction | 120 |
Mine Planning Criteria | 120 |
Modifying Factors | 122 |
Indicated Mineral Resources to Probable Mineral Reserves Conversion Factors | 124 |
Life of Mine Production Scheduling and Budgeting | 125 |
Process Overview | 125 |
LoM Production Schedule for Stillwater Mine | 126 |
Life of Mine Production Schedule for East Boulder Mine | 128 |
Mining Equipment | 129 |
Stillwater Mine | 129 |
East Boulder Mine | 130 |
Logistics | 131 |
Stillwater Mine | 131 |
East Boulder Mine | 132 |
Underground Mine Services | 133 |
Stillwater Mine | 133 |
vi
East Boulder Mine | 136 |
Manpower | 140 |
PROCESSING AND RECOVERY | 143 |
Mineral Processing Methods | 143 |
Background | 143 |
Ore Processing | 143 |
Stillwater Concentrator | 143 |
East Boulder Concentrator | 147 |
Concentrator Process Control Sampling | 151 |
Smelting and Refining | 152 |
Background | 152 |
Smelter | 152 |
Base Metal Refinery | 157 |
PGM Prill Splits | 161 |
Processing Logistics | 161 |
INFRASTRUCTURE | 163 |
Stillwater Mine Complex | 163 |
Concentrator Infrastructure | 163 |
Tailings Storage Facilities | 163 |
Power | 166 |
Bulk Water | 167 |
Roads | 168 |
Equipment Maintenance | 168 |
Buildings | 169 |
Transportation | 171 |
East Boulder Mine Complex | 172 |
Concentrator Infrastructure | 172 |
Tailings Storage Facilities | 172 |
Power | 174 |
Bulk Water | 174 |
Roads | 176 |
Buildings | 176 |
Equipment Maintenance | 177 |
Transportation | 178 |
Dry Fork Waste Rock Storage Area | 178 |
Columbus Metallurgical Facility | 178 |
MARKET STUDIES | 180 |
Introduction | 180 |
vii
PGM Market Overview | 180 |
Platinum and Palladium Demand and Supply | 181 |
Demand Drivers | 181 |
Platinum | 181 |
Palladium | 181 |
Palladium and Platinum Pricing Outlook | 181 |
Metals Marketing Agreements | 182 |
The Columbus Metallurgical Complex | 182 |
Precious Metals Refining | 182 |
Wheaton International Streaming Agreement | 182 |
The 2020 Palladium Hedge | 183 |
ENVIRONMENTAL STUDIES, PERMITTING, PLANS, NEGOTIATIONS/AGREEMENTS | 184 |
Social and Community Agreements | 184 |
Environmental Studies, Permitting and Plans | 185 |
Overview of Environmental Legislation and Regulation | 185 |
Environmental Setting and Factors | 190 |
Environmental Studies | 190 |
Permitting Status and Compliance | 194 |
Requirements for Environmental Monitoring, Closure and Post Closure, and Management | |
Plans | 220 |
Reclamation Plans and Costs | 229 |
CAPITAL AND OPERATING COSTS | 235 |
Overview | 235 |
Capital Costs | 235 |
Background | 235 |
Stillwater Mine | 235 |
East Boulder Mine | 239 |
Columbus Metallurgical Complex | 242 |
Operating Costs | 244 |
Background | 244 |
Stillwater Mine | 244 |
East Boulder Mine | 245 |
Columbus Metallurgical Complex | 246 |
ECONOMIC ANALYSIS | 251 |
Background | 251 |
Economic Viability Testing Method | 251 |
Economic Assumptions and Forecasts | 252 |
Taxation | 252 |
viii |
Metal Price Forecast | 252 | |
Discount Rate | 252 | |
DCF Results and Sensitivity Analysis | 252 | |
DCF Model | 252 | |
Net Present Values | 256 | |
Internal Rate of Return | 256 | |
Sensitivity Analysis | 256 | |
OTHER RELEVANT DATA AND INFORMATION | 258 | |
Catalytic Converter Recycling Business | 258 | |
Background | 258 | |
Recycle Processing | 258 | |
Recycling Operations | 259 | |
INTEPRETATION AND CONCLUSIONS | 260 | |
RECOMMENDATIONS | 264 | |
QUALIFIED PERSONS' CONSENT AND SIGN-OFF | 265 | |
REFERENCES | 266 | |
List of Figures | ||
Figure 1: | Location of Sibanye-Stillwater US PGM Operations in Montana | 14 |
Figure 2: | Sibanye-Stillwater US PGM Operations Mineral Title and Tenure Map | 19 |
Figure 3: | Regional Geology of the Stillwater Complex and Surrounds | 33 |
Figure 4: | South to North Sections Through Stillwater Mine Showing Subsurface Geology | 34 |
Figure 5: | A Schematic Section through Stillwater Mine Depicting the Horseman Thrust | |
System | 34 | |
Figure 6: | General Stratigraphy of the Stillwater Complex | 36 |
Figure 7: | Typical Stratigraphic Sequence and Pd-Pt Grade Profiles of the J-M Reef | 39 |
Figure 8: | West to East Schematic Section Showing Variability in Stratigraphy and Impact | |
on the J-M Reef at Stillwater Mine | 41 | |
Figure 9: | West to East Section Showing Geological Blocks of the J-M Reef at Stillwater Mine | |
........................................................................................................................................ | 42 | |
Figure 10: West to East Section Showing Geological Blocks of the J-M Reef at East Boulder | ||
Mine | 43 | |
Figure 11: Underground Definition Diamond Drilling Pattern | 46 | |
Figure 12: Drillhole Layout for Stillwater Mine | 48 | |
Figure 13: Drillhole Layout for East Boulder Mine | 49 |
ix
Figure 14: Sub-surface Water Basin in the Stillwater East Mine Area | 54 |
Figure 15: Hydrogeological Drillhole Locations along Adits in the Stillwater East Section | 55 |
Figure 16: Average Water Inflow at East Boulder Mine | 57 |
Figure 17: Test Sites for In Situ stress Measurements at Stillwater Mine | 59 |
Figure 18: Test Sites for In Situ Stress Measurements at East Boulder Mine | 60 |
Figure 19: Repeat Data Analysis for Stillwater Mine | 67 |
Figure 20: Repeat Sample Data Analysis for East Boulder Mine | 67 |
Figure 21: Blank Sample Data Analysis for Stillwater and East Boulder Mines | 68 |
Figure 22: Laboratory Standard MF-14 Data Analysis | 69 |
Figure 23: Laboratory Standard MF-15 Data Analysis | 69 |
Figure 24: Laboratory Standard MF-16 Data Analysis | 69 |
Figure 25: Laboratory Standard MF-18 Data Analysis | 70 |
Figure 26: Laboratory Standard MF-20 Data Analysis | 70 |
Figure 27: Laboratory Standard MF-21 Data Analysis | 70 |
Figure 28: Scatter plot of Composite UHW vs. 2E Grade for Stillwater Mine | 77 |
Figure 29: Scatter plot of Composite UHW vs. 2E Grade for East Boulder Mine | 77 |
Figure 30: Histogram Plot of Composite 2E Grades for Stillwater Mine | 78 |
Figure 31: Histogram Plot of Composite 2E Grades for East Boulder Mine | 78 |
Figure 32: Spatial Analysis of FCW Continuity | 80 |
Figure 33: Illustration of Reef Channel Wireframe Model Terminated at a Fault at Stillwater | |
Mine | 82 |
Figure 34: Illustration of Reef Channel Wireframe Model Terminated at Dykes at East Boulder | |
Mine | 83 |
Figure 35: J-M Reef Geological and Structural Models for Stillwater Mine | 84 |
Figure 36: J-M Reef Geological and Structural Models for East Boulder Mine | 85 |
Figure 37: Modelled 2E Grades and Classification for Stillwater Mine | 88 |
Figure 38: Modelled 2E Grades and Classification for East Boulder Mine | 89 |
Figure 39: Blitz Mean 2E Grade (opt) by Easting | 91 |
Figure 40: Frog Pond East Mean 2E Grade (opt) by Easting | 91 |
Figure 41: Mineral Reserve classification for Stillwater Mine | 102 |
Figure 42: Mineral Reserve classification for East Boulder Mine | 103 |
Figure 43: Overhand and Underhand Ramp and Fill Mining Methods | 108 |
Figure 44: Sub-level Extraction (Longitudinal) Long Hole Open Stoping | 109 |
Figure 45: Transverse Long Hole Open Stoping | 110 |
Figure 46: Generalized Underground Layouts for Stillwater and East Boulder Mines | 119 |
Figure 47: Typical Ramp and Fill Stope Design | 122 |
Figure 48: LoM RoM ore production schedule for Stillwater Mine | 127 |
Figure 49: LoM Production Schedule for East Boulder Mine | 129 |
Figure 50: Stillwater Mine Compressed Air Service Map | 135 |
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Sibanye Stillwater Limited published this content on 13 December 2023 and is solely responsible for the information contained therein. Distributed by Public, unedited and unaltered, on 24 December 2023 17:33:44 UTC.