Announcement PDF BUTCHERBIRD EXPANSION STUDY Growing Manganese Production to Capture Economies of Scale Element 25 Limited ABN 46 119 711 929 ASX E25 element25.com.au January E25 BUTCHERBIRD EXPANSION FEASIBILITY STUDY2024 | 1 TABLE OF CONTENTS Feasibility Dashboard and Highlights 3 Cautionary Statements 5 Forward Looking Statements 6 Expansion Study Summary 7 Geology 12 Resource Estimate and Mining Reserve 13 Mining 13 Processing 18 Logistics and Ore Transport 24 Project Infrastructure 25 Manganese Market 27 Economic Analysis 29 Material Assumptions 33 Business Plan Risks 42 Environmental, Heritage and Approvals 43 Project Execution 45 Consultants and Contributors 45 Competent Persons Statement 46 Acronyms & Definitions 47 Butcherbird Expansion Feasibility Study Targets 1.1 Mtpa Manganese Production to Capture Economies of Scale. A strong result supporting progress toward a Decision to Mine. Element 25 Limited (Company or E25) (ASX: E25) is pleased to announce that it has completed a Feasibility Study (Study or FS) to investigate the potential to expand the production of manganese concentrate at the Company’s 100% owned Butcherbird Project (Project), located in the southern Pilbara region of Western Australia. The Study demonstrates strong economics with robust economic returns and rapid capital payback. The financial summary of the Study outcomes are shown below. Capital Cost NPV8 IRR Cashflow Payback AU$49.8 AU$228M 113% AU$57.3M 1.2 (incl. contingency) (Pre-tax, real) (annual) (years) HIGHLIGHTS The FS examines the expansion to 1.1Mtpa manganese concentrate production using expanded open-cut mining methods, a modified primary comminution circuit and a dense media separation (DMS) back-end solution to optimise grade and recoveries. The expansion establishes Butcherbird as a low-cost Mn operator (USD 2.76/dmtu C1 cost) able to produce at a cost lower than the low manganese sale price points seen within the Mn market. The FS utilises all the available measured and indicated resources within the mine plan supporting this Study. The Company plans to undertake infill drilling in areas containing Inferred Resources, outside the current mine plan, within the next 12 months targeting an additional 20-25 years of mine reserves at the proposed production levels. The Measured, Indicated and Inferred Mineral Resources used to support the 7.2 years mine life from 2024 to 2031 represents 36.0% of the total mineral resource inventory within the granted mining lease M52/1074. Low capital requirement of AUD 49.8M capital. Average base case annual operating cashflow of AUD 57.3M at full production. No changes to the Proven and Probable Ore Reserve of 49.2Mt at 10.2% Mn containing 5.0Mt Mn (4.1Mt Recoverable Mn). Forecast cashflows generate a simple paybackperiod of 14months from start of operations. Expanded mining production and process commissioning is currently scheduled to commence within 11 months, subject to final investment decision and securing project financing. The base case involves an annual production and sale of 1.1M tpa of lump manganese ore grading 32% Mn. The concentrate production strategy complements and enhances the Company’s plan to develop the proposed high purity manganese sulfate (HPMSM) plant in Louisiana to supply offtake partners General Motors LLC(GM) and Stellantis NV (Stellantis) with high purity manganese for EV battery manufacture1. 1 Reference: ASX Releases dated 9 January 2023 and 26 June 2023. E25 BUTCHERBIRD EXPANSION FEASIBILITY STUDY | 4 CAUTIONARY STATEMENTS The production target referred to in this announcement is based on 26% Measured Resources, 53% Indicated Resources and 21% Inferred Resources for the 7.2 years mine life. The mine plan comprises 86% of current Measured and Indicated Resources within the Yanneri Ridge resource, located East of the Goldfields Gas Pipeline. The Company has used Inferred Mineral Resources as part of the production scenario where it is mined as part of the mine plan and the impacts of the use of Inferred mineralisation is included within the report. There is a low level of geological confidence associated with inferred mineral resources and there is no certainty that further exploration work will result in the determination of indicated mineral resources or that the production target itself will be realised. The use of Inferred mineralisation is not a determining factor in the viability of the project. The Company intends to upgrade the mineral resource inventory within 2024 with the Yanneri Central and Coodamudgi Central resource areas. This potential extension has not been factored into the mine plan for this feasibility and will be subject to a revised feasibility if the resource is upgraded. The Study is based on the material assumptions described elsewhere in this announcement. These include assumptions about availability of funding. The Company considers all the material assumptions to be based on reasonable grounds, however there is no certainty that they will prove to be correct or that the range of outcomes indicated by the Study will be achieved. The Company is fully funded based on currently cashflow forecasts. The Company has concluded that it has a reasonable basis for providing the forward-looking statements included in this announcement and believes it has “reasonable basis” to expect it will be able to fund the development of the Project using existing cash reserves. The Study focuses on a development option which has been selected as the most likely mining start up scenario. The Expansion Study has targeted a part of the manganese resource where it is considered that reasonable grounds exist for the production target to be achieved in both the grade and size which has been reported. This Study development options are also well supported by the larger Butcherbird Mineral Resource where there are additional Indicated and Inferred Mineral Resources. E25 BUTCHERBIRD EXPANSION FEASIBILITY STUDY | 5 FORWARD LOOKING STATEMENTS Some of the statements contained in this report are forward-looking statements. Forward-looking statements include, but are not limited to, statements concerning estimates of tonnages, expected costs, statements relating to the continued advancement of Element 25 Limited’s projects and other statements that are not historical facts. When used in this report, and on other published information of Element 25 Limited, the words such as ‘aim’, ‘could’, ‘estimate’, ‘expect’, ‘intend’, ‘may’, ‘potential’, ‘should’ and similar expressions are forward looking statements. Although Element 25 Limited believes that the expectations reflected in the forward-looking statements are reasonable, such statements involve risks and uncertainties and no assurance can be given that the actual results will be consistent with these forward-looking statements. Various factors could cause actual results to differ from these forward-looking statements including the potential that Element 25 Limited’s Project may experience technical, geological, metallurgical, mechanical problems, changes in manganese price and other risks not anticipated by Element 25 Limited. Element 25 Limited is pleased to report this summary of the study in a fair and balanced way and believes that it has a reasonable basis for making the forward-looking statements in this announcement, including with respect to any mining of mineralised material, modifying factors, production targets and operating cost estimates. This announcement has been compiled by Element 25 Limited from the information provided by the various contributors to the announcement. E25 BUTCHERBIRD EXPANSION FEASIBILITY STUDY | 6 EXPANSION STUDY SUMMARY Element 25 Limited (Company, Element 25 or E25) (ASX: E25) is pleased to announce that it has completed a Feasibility Study (Study) to investigate the potential to expand the production of manganese concentrate at the Company’s 100% owned Project, located in the southern Pilbara region of Western Australia. This Study has been developed from the Pre-Feasibility Study update released in December 2020 and utilises the production data from current operations along with a detailed review of the process flow design to optimise the design of an expanded processing facility. The Project consists of eight known manganese mineral resources located in an approximately 600km2 area of the southern Pilbara region, approximately 1,050km North of Perth and 130km South of Newman, Western Australia (WA). The Butcherbird site is accessible directly from the Great Northern Highway. Element 25 has held exploration tenure in the Butcherbird area since 2009 and commenced mining and manganese concentrate processing operations at Butcherbird in early 2021. Since then, the Company has exported eleven shipments of Manganese concentrate to customers in Asia. The Project is 100% owned by the Company and comprises the granted Mining Lease M52/1074 and two granted exploration licences E52/2350 and E52/3606 as well as several granted and pending Miscellaneous Licences required for Project infrastructure. Mining Lease M52/1074 encompasses the Yanerri Main, Yanerri Central and Yanneri West and Coodamudgi Central and Coodamudgi West manganese deposits. This expansion plan is predicated on the mining of the measured and indicated mineral resources located at Yanneri East, i.e.: East of the Goldfields Gas Pipeline. The Study does not rely on the inclusion of Inferred Mineral Resources within the granted Mining Lease, however the Company intends to undertake additional infill drilling to look to expand the available mining inventory in coming months. The Company has two Native Title mining agreements in place servicing the project area and covering all planned production areas used in the Study. The Butcherbird project is located on two pastoral stations and the Company has access agreements in place to allow project expansion to be undertaken. This expansion Study includes updated macro-economic inputs and other design parameters where appropriate based on current market conditions and on the improved understanding of the optimal processing methodology derived from production data since the commissioning of the current processing plant. The Study contemplates a revised comminution and procession circuit based on learnings gained from the operation of the current Butcherbird processing facility since 2021. Changes to the processing circuit include the use of a mineral sizer for primary comminution, and a DMS drum for final beneficiation. E25 BUTCHERBIRD EXPANSION FEASIBILITY STUDY | 7 A summary of the parameters used in this study include: • DMS process recovery of 96%. • Increased manganese concentrate production to 1.1Mtpa. • Increased ore recovery and decreased ore loss due to change in processing equipment. • Exchange rate (USD:AUD) of 0.66 from 2024, with a longer-term assumption of 0.69 from 2027 onwards. • Capital cost estimate of AUD 49.8M including: • Construction of expanded processing infrastructure; • Construction of a nearby mining camp, at a capital cost of AUD 5.5M; and • Construction of an airstrip to enable direct flights to Butcherbird, at a capital cost of AUD 2.2M. • An updated site organisation chart has been developed with updated costs reflective of the proposed expansion. • Updated mining costs based on the expanded mining requirements. • Updated sustaining capex involving an expanded tails storage facility (TSF). • Updated manganese ore pricing to reflect current spot and forecast pricing. The Study results confirm that the robust economics of the site are maintained and improved for the planned expansion offering the Company opportunities to further improve the economics and performance of the Project by taking advantages of the inherent economies of scale achieved in the larger scale production operations. This results in better utilisation of mining and processing equipment, improved operational efficiencies and better utilisation of the large resource/reserve base underpinning the Project. Ongoing resource delineation drilling is already planned to increase the mine life by adding Yanneri Central and Coodamudgi Central into the Indicated/Measured resource categories in H1 2024. The seven-year project utilises 86% of the Measured resources2 and 61% of the Indicated resources available within the Butcherbird resource base. E25 BUTCHERBIRD EXPANSION FEASIBILITY STUDY | 8 The use of inferred resources is not a determining factor for project viability of the expansion, See Table 1 and Figures 6 to 8 below. Table 1: Impact of Inferred Mineralisation on Key Financial Outputs Including Inferred Excluding Inferred NPV8 (AUD M) (Pre tax) 228.2 163.9 IRR (%) 113% 95% Mine Life Utilising existing Mining Reserves (Years) 7.2 5.8 Annual Cash Flow (AUD M) 57.3 53.9 Resources Utilised (Mt) % Measured 12.2 26% Indicated 25.1 53% Inferred 10.2 21% Total 47.4 100% Table 2: JORC Resource Mineralisation Usage by Scenario 2 Reference: Company ASX Announcement dated 17 April 2019. E25 BUTCHERBIRD EXPANSION FEASIBILITY STUDY | 9 KEY OUTCOMES OF BASE CASE This FS includes preliminary pit shells, estimated mining and production schedules and metallurgical testing relevant to manganese processing and recovery. Capital costs were based on detailed engineering designs and industry sourced quotations provided by technical experts within Element 25 and by external consultants. Operating costs were sourced from supplier quotations for major operational contracts including mining, ore haulage and camp facilities. The balance of the operating costs were sourced from quotations and database costs and are considered to be at ±15% level of estimation. Open pit optimisation, design and mine scheduling were performed by an external consultant, overseen by Element 25 staff, based on design and operating parameters provided by Element 25.The Study base case for the Feasibility Study consists of: • An Open pit mining and beneficiation operation producing 1.1M tpa (years 1-7) of manganese lump concentrate at an average grade of 32% Mn per annum. • An initial mine life of 7.2 years based on the use of existing Proved and Probable Ore Reserves3 with Inferred mineralisation used where it is mined to gain access to the Proved and Probable reserves in the later years of the Project. • The current project scenario utilises 26% Measured and 53% Indicated and 21% Inferred resources, with years 1-4 using 43% Measured and 52% Indicated and 5% Inferred resources. • Inferred mineral resources are included in the base case study, comprising 21% of the 7.2 year ore supply. The inferred resources are not a determining factor for project viability; Refer Table 1 above. • Operating expenses, C1, over the life of mine are currently estimated at AUD 4.02 / Dry Metric Tonne Unit (dmtu) (USD 2.76/ dmtu), assuring a low-cost operation that will be profitable throughout the manganese price cycles. • Low estimated capital costs of AUD 49.8M (USD 32.9M) including working capital. Using a manganese concentrate price curve, based on market analysis provided by Project Blue with a long-term average manganese price of USD 5.75/dmtu Mn 44% Cargo Insurance and Freight (CIF) China, NPV8 (Net Present Value at 8% discount factor) pre-tax is AUD 228.2M (USD 150.6M), post-tax AUD 150.6M (USD 99.4M), with an Internal Rate of Return (IRR) of 113%. The Project NPV8 of AUD 228.2M highlights that the Project is robust and offers returns even at conservative pricing assumptions. The Project breaks even at a manganese price of USD 4.38/dmtu 44% CIF China for the life of the Project. The assumptions for the expansion study are listed and detailed within the remainder of the Study. 3 Reference: Company ASX Announcement dated 19 May 2020. E25 BUTCHERBIRD EXPANSION FEASIBILITY STUDY | 10 DEVELOPMENT TIMELINE A project implementation plan and schedule has been developed based on forecast lead times for equipment procurement, permitting, project financing and construction. The total time required for project delivery from contract signature to start of commissioning is estimated at approximately 11 months from Final Investment Decision (FID). Figure 1: Project Development Timeline EXPANSION PROJECT APPROACH Element 25 have been working closely with specialist WA project delivery consultant, ProjX, for the proposed Butcherbird expansion project. ProjX designed the original Butcherbird facility and managed all project and construction activities, and as the owners team. ProjX and Element 25 are jointly designing the proposed Butcherbird expansion plant, which incorporates plant design and supply by specialist vendors of key process equipment. Given that various process equipment is subject to long lead times, an optimised project delivery schedule is currently being developed that aims to identify all opportunities for schedule improvement, including Early Contractor Involvement (ECI) partnerships to identify long lead time items for early procurement, optimisation of manufacture strategy (i.e. local manufacture overseas), fast track of certain design elements, and innovative construction methodologies. Element 25 are targeting a project period of 11 months, followed by a 2 month commissioning period. E25 BUTCHERBIRD EXPANSION FEASIBILITY STUDY | 11 1. GEOLOGY The manganese mineralisation at the Project with the most economic value occur where the manganiferous shales of the Ilgarari formation intersect the weathering profile and display a supergene overprint where deep chemical weathering have upgraded the grade of the manganese and partitioned the manganese mineralisation into discrete high grade bands, resulting in an ore that is amendable to simple physical beneficiation. Figure 1. Yanneri Ridge Deposit cross section with simplified geology Figure 2 illustrates the interlayered supergene manganese layers in the manganiferous shale unit which is the primary ore source at Butcherbird. The photo was taken during the bulk sampling program conducted in December 20191 and is typical of the mineralisation style at the Project. Ore beneficiation is achieved by separating the nonmanganese bearing clays and shales via comminution, scrubbing, screening and dense media separation (DMS). Figure 2. Bulk Sample Trial Pit - Pit Wall showing Manganese Lithology 1 Reference: Company ASX Announcement dated 19 December 2019. E25 BUTCHERBIRD EXPANSION FEASIBILITY STUDY | 12 2. RESOURCE ESTIMATE AND MINING RESERVE 2.1 Resource Estimate The 2019 JORC Measured, Indicated and Inferred Mineral Resource Estimate was completed by IHC Robbins following a major infill drilling program in 2018. The Mineral Resource including mining depletion to 30 June 2023 is shown below. Table 1. 2019 Butcherbird Manganese Project Mineral Depleted Resource Estimate2 Category Tonnes (Mt) Mn (%) Fe (%) Si (%) Al (%) Measured 14.1 11.4 11.7 20.6 5.7 Indicated 40.8 10.0 11.0 20.9 5.8 Inferred 206.0 9.8 11.4 20.8 5.9 Total 260.9 9.9 11.4 20.8 5.9 Notes: • Reported at a 7% Mn cut-off for the Measured and Indicated categories and an 8% Mn cut-off for the Inferred categories. • All figures rounded to reflect the appropriate level of confidence (apparent differences may occur due to rounding) 2.2 Mining Reserve Based on the results of the Butcherbird Concentrate Pre-Feasibility Study5, E25 published a Maiden Ore Reserve for the Project of 50.5Mt in May 2020 in the Proved and Probable categories. The depleted Ore Reserve summary as at 30 June 2023 is shown below: Table 2. Butcherbird Depleted Ore Reserve Summary 2 Tonnes Grade (Mt) (Mn%) Proved 13.0 Probable Total Classification Contained Mn (Mt) Recovered Mn (Mt) 11.1 1.4 1.2 36.2 10.1 3.6 3.0 49.2 10.2 5.0 4.1 The estimated ore reserves and/or mineral resources underpinning the production target have been prepared by a competent person or persons in accordance with the requirements in Appendix 5A (JORC Code). 3. MINING The mine plan has been strategically crafted to harness the distinctive tabular structure of the mineral deposit at Yanneri Ridge, enabling the establishment of an uncomplicated and cost-effective mining process. The mining operations will employ multiple pit configurations, including excavation beneath the water table. Open Pit dewatering measures will be implemented, as necessary. Geotechnical Studies supported by current mining activities have identified that the orebody will mostly be mineable using free dig techniques. In specific segments of the Yanneri pits, drilling and blasting will be required to remove the resilient cap rock. Ore extraction from the Yanneri central and the Coodamudgi Central pits will necessitate its transportation and any other 2 Reference: Element 25 Limited Reserve Statement lodged with ASX 19 May 2020. E25 BUTCHERBIRD EXPANSION FEASIBILITY STUDY | 13 waste material across APA’s Goldfields Gas Pipeline (GGPL). An initial blueprint has been formulated to incorporate engineered crossovers on the GGPL at 3 strategic locations to facilitate this process without any disturbance or risk to the GGPL. Mining has been scheduled to maintain ore supply to the processing plant to meet production requirements. Mining will consist of hydraulic excavators mining 2.5m tall benches and delivering the ore to the ROM Pad via diesel haul trucks, where it will be fed directly to the processing plant or stockpiled for future feed. To enable the excavator to efficiently extract the ore, the ore will be cross ripped with a dozer prior to mining. This is shown schematically below in Figure 3. The Butcherbird mining area is a part of the Yanneri mineral resource delineated to the west by the GGPL and to the east by the Mining Lease boundary. It covers an area of some 2150m East-West and 1,000m North-South, centered around the processing plant. The optimised final pit shapes for Yanneri East Pit have a mine life of 7.2 years. These pits target the higher-grade proved and probable mining reserve and allows access for mine scheduling with minimal waste removal from the Yanneri Ridge mineral resource. Figure 3. Mining System Schematic The pit designs contain 47.7Mt of ore at an average grade of 9.7% Mn and is expected to be mined along with 12.3Mt of waste for an overall strip ratio of 0.26 to 1 (Waste: Ore volume). The optimisation of the pit shells uses a base price of USD4.50/dmtu 44%Mn CIF China. The pit design on which the expansion is modelled contains 26% Measured Resources 53% Indicated Resources and 21% Inferred Resources scheduled at the end of the 7.2-year mining life. A preliminary mining schedule is illustrated in Figure 4 below. The current mining schedule was designed as a series of nested pits within the ultimate pit shell. Project economics are not significantly impacted if Inferred resources were utilised later in the life of mine schedule. Given that there is a low level of geological confidence associated with Inferred Mineral Resources, their treatment as an ore source after the Measured and Indicated ore is depleted is considered conservative. Resource definition drilling has been included as an operating cost to allow the conversion of Inferred to Indicated mineralisation. E25 BUTCHERBIRD EXPANSION FEASIBILITY STUDY | 14 Figure 4. Butcherbird Site Layout showing Open Pit Staging, Looking Northeast 3.1 Pit Design Although not anticipated in the original planning at Butcherbird, Mining has encountered some relatively small areas of caprock, that will require Drill and Blast operations. These areas include mainly the upper levels of the Yanneri resource, down to a depth of approximately 6m from the surface must be drilled and blasted to ensure the hard cap rock is fully broken. The drill and blast processes to be deployed will require the use of a contractor with specialized blasting skills with significant experience of blasting close to critical infrastructure (the Goldfields Gas Pipeline). This is to ensure no vibration induced disturbance on the Goldfields Gas Pipeline adjacent to the mining operations that will require blasting. The costs for the drill and blasting have been incorporated into the financial model. The rest of the Yanneri Ridge mineralisation within Mining Lease M52/1074 will be mined by dozer ripping and extraction using conventional hydraulic excavators to mine directly from the mining face into haul-trucks which will transport ore to the crusher. Similarly, waste will be mined by diggers and transported to the dedicated waste dump. Mining costs used for the pit optimisation and subsequent financial evaluation were sourced from the companies mining contractor in September 2023, which was based on the 7.2-year mining plan for the expanded operation at Butcherbird. Mining factors used for the pit optimisation include 95% ore recovery and 5% dilution. Because all mineralisation within the pit designs will be processed these factors are considered appropriate. The open pit design is based on pit shells derived from an open pit optimisation study using mining costs of $9/bcm mined which include Mining, ROM Management and Fines disposal to the TSF, processing of $13.60/t product, and administration of $6.85/t product. With ex-site costs $55/t ore haulage and $16/t port charges were used, together with a manganese concentrate price based on a USD 4.50/dmtu CIF 44% China. Mining production by JORC resource category and average yearly manganese grade is shown below as Figure 5. Ore Supply by JORC Resource Category. E25 BUTCHERBIRD EXPANSION FEASIBILITY STUDY | 15 Figure 5. Ore Supply by JORC Resource Category A summary of the mining schedule showing ore and waste movement as well as average stripping ratio is shown below in Figure 7. Figure 6. Mining Material Movement and Stripping Ratio 3.2 Geotechnical and Diggability Assessment Peter O’Bryan and Associates were engaged to conduct an open pit geotechnical assessment study on the Yanneri Ridge section of the deposit. The Study was based on nine geotechnical holes and was completed in March 2019. E25 BUTCHERBIRD EXPANSION FEASIBILITY STUDY | 16 A prefeasibility geotechnical assessment for open pit mining was undertaken for the Yanneri Ridge Deposit by Peter O’Bryan & Associates in March 2019. The assessment utilised information on geotechnically logged boreholes from June 2018 to conduct wall stability analysis. Kinematic Analysis and Limit Equilibrium Analysis were undertaken under the following conditions: • Likely Case Materia Properties -Static loading. • Worst Case Materia Properties -Static loading. • Worst Case Materia Properties -Seismic loading. The key findings of the base case wall design parameter limits for all walls in the Yanneri Ridge pit considered highly conservative design parameters which include: • Face height 5m from surface to 5m depth. • Face height 10m below 5m depth for the first 10m. • Face angles 50˚ from surface to 15m depth. • Face angles 60˚ below 15m depth with a face height of 10m. • Berm width - 5m throughout. Subsequent geotechnical inspections on site by Peter O’Bryan and Associates have supported the original findings and design considerations and show that there is a very low pit stability risk at Butcherbird. 4D Geotechnics (4DG) were engaged and completed two detailed diggability reports evaluating likely excavation rates. These reports were completed on 18 July 2018 and 15 March 2019. The 4DG study used ten diamond drill holes. Hole sections were assessed and tabulated with ninety-seven individual ratings. Of these ninety-seven ratings the high values were two values above 60 (62 at 3.9m to 6.0m and 68 at 1.0m to 1.3m) and seven values in the 51 to 60 range. The study concludes that based on the results of their examination and testing of ten diamond holes in the Yanneri Ridge area, the area to be mined will mostly be free digging. Mining activities at Butcherbird have mostly been completed since 2021 as free-dig. However, some areas, mostly on the upper portions of the Yanneri resource have not been able to be mined using Free-Dig or local ripping alone. The Feasibility has included a drill and blast component to allow for the drilling and blasting of the cap rock in these areas. 3.3 Goldfields Gas Pipeline The location of the GGPL has been specifically included in assessment of the geotechnical stability involved with mining adjacent to the GGPL. The recommended open pit wall design profile and proposed stand-off from the Goldfields Gas Pipeline reserve make it extremely improbable for ground disturbance due to instability within the adjacent pit wall to even approach the reserve boundary. Material loss due to erosion over time cannot conceivably cause pit crest retreat to approach the pipeline reserve. Debris from mass wastage would remain at/ near the toe of the pit wall and retard and eventually choke the process. This can be alleviated by the placement of mine wastes against the walls whilst mining other areas of the open pit. The pit sectors adjacent to the pipeline are designed to allow a stand-off of ≥ 75m from the crest of the ~25m deep pit to the near boundary of the pipeline reserve. This approach places the outer toe of an abandonment bund ≥ 50m from the pipeline reserve boundary. Limit equilibrium analysis of slopes adjacent to the gas pipeline under anticipated likely case conditions yield a minimum FS of 3.71 for geometrically feasible rotational shearing surfaces approaching the pipeline reserve (Figure 14), noting however that the lowest FS of a surface that intersects the natural surface at the pipeline reserve boundary is ~ 4.8. E25 BUTCHERBIRD EXPANSION FEASIBILITY STUDY | 17 3.4 Mining Costs Mining costs were sourced from a quotation from the companies mining contractor, ReGr