Perseus Mining Proceeds with Development of the Nyanzaga Gold Project

28 APRIL 2025

NEWS RELEASE

PERSEUS MINING PROCEEDS WITH DEVELOPMENT OF THE NYANZAGA GOLD PROJECT

OVERVIEW

Perth, Western Australia/ April 28, 2025/ Perseus Mining Limited (ASX/TSX: PRU) is pleased to announce that a Final Investment Decision (FID) has been taken to develop the Nyanzaga Gold Project (NGP) in Tanzania, following an update of the NGP Feasibility Study (FS).

Perseus has committed to invest approximately US$523 million (including contingency) to develop and prepare for the operation of the mine that is expected to produce first gold in Q1 2027. The NGP development will be solely financed via interest free, intercompany loans provided by Perseus from its existing cash and bullion balance of US$801 million as of 31 March 2025.

In anticipation of an affirmative FID, Perseus has spent approximately US$27.5 million to date to build project team capacity and commence early works that include site establishment, installation of temporary construction accommodation, and bulk earthworks as well as implementing the Relocation Action Plan (RAP) to construct new dwellings for people impacted by future construction and operating activities.

The updated FS incorporates findings and recommendations from a range of comprehensive technical assessments made by Perseus’s technical team. Notably, Perseus has opted for a large scale, wholly openpit mining operation, for the first phase of development, in preference to a smaller scale, combined open pit

• underground option contemplated by the previous owners. Key metrics associated with the NGP include

the following:

Production & Cost Metrics (100% basis):

• Total gold production over an 11-year, Phase 1 mine life is currently estimated to be 2.01 Moz based on a JORC 2012 Probable Ore Reserve of 52.0 Mt @ 1.40 g/t gold for 2.3 Moz.
• Gold production averages over 200,000 ounces of gold per annum from FY28 to FY35, with peak production of 246,000 ounces in FY28.
• Over the life of the mine, the estimated average All-In Site Cost (AISC) is US$1,211/oz.
• Capital cost for the plant and site infrastructure is estimated at US$472 million inclusive of US$49 million of contingency, and pre-production capital of US$51 million, giving a total capital cost to first gold pour of US$523 million.

Investment Metrics (100% basis)¹:

Applying Perseus’s assumed long-term gold price of US$2,100/oz, the NGP’s investment metrics include:

• Undiscounted free cashflow pre-tax of US$1,133 million and post-tax of US$706 million, (or US$2,252 million pre-tax and US$1,471 million post-tax at a gold price of US$2,700/oz.)
• Net Present Value (NPV10%) of US$404 million pre-tax and US$202 million post-tax, (or US$1,010 million pre-tax and US$617 million post-tax at a gold price of US$2,700/oz).
• Internal Rate of Return (IRR) of 26% pre-tax and 19% post-tax (or 45% pre-tax and 34% post-tax at a gold price of US$2,700/oz).

The FID to proceed with developing the NGP builds upon Perseus’s demonstrated capacity to successfully develop and efficiently operate modern gold mines on the African continent. Perseus has previously successfully developed, and is now operating three gold mines including Edikan, Sissingué, and most recently, the Yaouré gold mine that was delivered ahead of schedule and under budget in 2020, using many of the same team that will be deployed on the NGP development. The FID also comes following constructive engagement with the Government of Tanzania to clarify terms of an existing Framework Agreement that sets out the basis on which the NGP will be developed and operated, as well as the Shareholder’s Agreement between the Tanzanian Government and Perseus.¹

A second phase of resource definition drilling is currently underway at the NGP with the aim of converting Inferred Mineral Resources into Indicated Mineral Resources, which would potentially enable the Ore Reserve to be materially expanded and the life of the NGP operation extended during the second phase of the Project, beyond the currently projected 11-year mine life.

Perseus’s Managing Director and CEO Jeff Quartermaine said:

“Perseus is very excited by its decision to proceed with the development of the Nyanzaga Gold Project and is looking forward to working alongside the Government of Tanzania to deliver a world class mining operation. Acquired in May 2024 through the successful takeover of OreCorp Limited, the Nyanzaga Gold Project will be the first major gold mine development in Tanzania in 17 years and represents a major step forward in terms of enhancing Tanzania’s reputation as a favourable destination for foreign investment.

Importantly, the addition of a high-quality, long-life gold mine such as the Nyanzaga Gold Mine to Perseus’s existing asset portfolio, that currently includes the Yaouré, Sissingué and Edikan gold mines, as well as the undeveloped Meyas Sand Gold Project, represents a significant upgrade for Perseus and is consistent with the Company’s strategy for building a sustainable, geopolitically diversified but African-focused gold business involving 3-4 operating mines that produce between 500–600koz of gold per annum at a cash margin of not less than US$500 per ounce, for every ounce produced.

With the development of the Nyanzaga Gold Project, Perseus continues to strengthen its claim to be recognised as one of the leading gold producers operating on the African continent.”

1 Note: Perseus owns an 80% contributing interest in the NGP together with the Government of Tanzania who owns a 20% non-contributing interest.

This announcement was approved for release by the Managing Director & CEO, Jeff Quartermaine.

PROJECT DETAILS

LOCATION

The NGP is located in north-western Tanzania, south of Lake Victoria within the Sengerema District of the Mwanza Region (Figure 1). The NGP is approximately 60 km southwest of Mwanza (Tanzania’s second largest city) and 7 km southeast of Ngoma, with the total area of the Project being 16,085 ha.

Figure 1: NGP location plan

The proposed site layout is presented in Figure 2.

Figure 2: NGP site layout plan

MINING

Based on the results of a techno-economic assessment, Perseus plans to mine the Nyanzaga (Tusker) and Kilimani deposits using a large open pit, as opposed to the smaller open pit and underground mine concept previously proposed by OreCorp in their 2022 Definitive Feasibility Study (DFS). A mining study completed in 2024 proposes a mining fleet that uses 180-350 t hydraulic excavators matched with 90-150 t off-highway dump trucks. Over the life of the NGP, 52.0 Mt of ore and 297.8 Mt of waste will be mined at an average strip ratio of 5.7 (Figure 3). Total material movement is forecast to peak during the period FY28 to FY32.

Figure 3: NGP ore and waste production profile over life of mine

PROCESSING

The NGP process flowsheet (Figure 4) is a conventional gold processing flowsheet that includes single stage gyratory crushing; SAG milling with pebble recycle and ball milling in closed circuit with hydrocyclones (SAB comminution); gravity gold recovery; pre-oxidation/cyanide-in-leach (CIL) to leach and adsorb precious metals from the milled ore to activated carbon; split AARL elution, electrowinning and smelting to recover precious metals from loaded activated carbon to doré; and SO2/air detoxification of CIL tailings before pumping and deposition to the Tailings Storage Facility (TSF).

Figure 4: Simplified process flow sheet for the NGP

Flowsheet selection is supported by an extensive body of metallurgical test work completed across 2016-2017 and 2022. Nameplate plant throughput for the process plant is 5 Mt per annum for the projected ore blend requiring the highest specific energy input (which is based on 85^th percentile specific energy for each ore type proportionally in the blend). Perseus notes the optionality to run at higher throughput rates based on ore specific comminution parameters, and major equipment selection and engineering has considered achieving higher volumetric throughput. Grind sensitivity test work indicates that all ore types are grind sensitive, with gold extraction increasing with fineness of grind. Techno-economic assessments identified an optimum grind size of P80 75 µm.

Ore will be processed through the NGP process plant across 11 financial years, with an average head grade of 1.40 g/t (Figure 5). Perseus has used the average specific energy for each ore type as the basis of calculating instantaneous mill throughput and considered 8,000 h/a runtime (91.3% of total hours per year) for production scheduling.

Figure 5: NGP process plant ore treatment rate and feed grade profile over life of mine

Variability gravity/leach test work demonstrated a range of extractions from 76% to 99% for gold. Oxide, sandstone and chert ore types were all shown to be free milling. While a small proportion of the mudstone ore exhibited mild preg-robbing characteristics, these were overcome by utilising a CIL circuit design. Metallurgical recovery of gold over the Life Of Mine (LOM) is expected to average 86.0% at grind size of P80 75 µm. A total of 2.01 Moz of gold are recovered over the life of mine, with total annual gold production of over 200 koz per annum achieved from FY28 to FY35, and peak production of 246 koz in FY28 (Figure 6).

Figure 6: NGP ounce production profile over life of mine

PROJECT INFRASTRUCTURE

The NGP is accessed from Mwanza, Tanzania's second largest city, by the sealed Mwanza – Geita Highway, crossing Smith Sound (an arm of Lake Victoria) via ferry or the recently constructed Kigongo – Busisi Bridge (John Pombe Magufuli Bridge), and then travelling on the unsealed regional road network for 35 km to Ngoma. The NGP area is approximately 9 km southeast of Ngoma, and an unsealed road is currently under construction to bypass Ngoma township and reach the NGP site.

Power will be supplied from the Tanzania Electric Supply Company Limited (TANESCO) operated national grid at the Bulyanhulu substation and delivered via a new 53 km long 220 kV transmission line.

Raw water for the site will be predominantly extracted from nearby Lake Victoria, with the water balance indicating a flow rate of 50-350 m³/h is required once the TSF decant return water supply becomes available (dependent on the season). Raw water supply will be supplemented by groundwater extracted from dedicated boreholes. Process water will be predominantly supplied by water recovered from the TSF decant. The TSF will comprise a cross-valley storage facility formed by three zoned earth-fill embankments. The TSF has been designed in accordance with the Australian National Committee on Large Dams (ANCOLD) Guidelines (2019), the Global Industry Standard on Tailings Management (GISTM, 2020), Implementation Guidance for the International Cyanide Code (International Cyanide and Management Institute, 2016) and the United Republic of Tanzania Ministry of Water Dam Safety Guidelines (2020). The TSF will store life of mine tailings production of 52.0 Mt, with the embankments constructed in stages. The full internal basin area and upstream batter slopes of embankments will be fully lined with high-density polyethylene (HDPE) liner. A permanent operations village will accommodate 350 personnel, management and skilled technical staff from outside the immediate NGP area. Temporary construction accommodation will be provided by the respective construction contractors. A bus service will be provided to and from local population centres for workers from local towns and villages.

ENVIRONMENT, SOCIAL & GOVERNANCE (ESG) CONSIDERATIONS

The Relocation Action Plan (RAP) remains a critical prerequisite for the progression of the NGP, with housing construction scheduled for completion by 1 October 2025 to support project timeline, budget adherence, and the preservation of Perseus social licence to operate. A comprehensive community engagement strategy, including livelihood restoration initiatives, is also underway to establish sustainable community relationships from project inception.

The Health, Safety and Environmental (HSE) framework for the NGP will align with Perseus's HSE Management System, supported by the EPCM contractor’s HSE programme during the construction phase, and will include the application of group-wide risk tools and fatality risk controls.

An Environmental and Social Impact Assessment and Environmental Management Plan (EMP) have been completed. Perseus is now working with the Tanzanian National Environment Management Council to update the EMP, following the recent updates to the site layout that were made in the Feasibility Study. A Project Security Development Plan has also been developed, aligned with Perseus’s standards, Tanzanian legislation and the Voluntary Principles on Security and Human Rights. A Memorandum of Understanding to formalise cooperation with the Tanzanian Police Force is also expected to be signed shortly.

PERMITTING

Tanzania has a mature regulatory framework that governs the construction and operation of mining projects in the country. Perseus has secured the relevant permitting approvals to initiate construction activities with subsequent permitting integrated into the master project schedule. As it stands, the approvals are not represented on the project critical path.

GOVERNMENT AGREEMENTS

Under prior ownership, two agreements were executed in 2021 with the Government of Tanzania that govern the joint venture ownership of the NGP (Agreements):

• Framework Agreement (FWA) setting out the investment and fiscal arrangements governing the NGP
• Shareholder Agreement (SHA) setting out the agreements between Perseus and the Government of Tanzania as shareholders of the NGP. This includes ratifying the 20% free carry Government of Tanzania ownership in the NGP

Since acquiring OreCorp and the NGP, Perseus has worked collaboratively with the Government of Tanzania to amend the FWA and SHA (Addendums). This was required to remedy uncertainty that existed post the release of the Mining State Participation Regulations issued in 2022 and other key fiscal matters. The Agreements and Addendums provide formal alignment in relation to the regulatory framework under which the NGP will be developed and operated.

At the time of this release, the Addendums are in agreed form subject to formal sign-off by the Tanzanian Attorney General.

CAPITAL COST ESTIMATE

The LOM project capital cost estimate of US$679.1 million development, pre-production, sustaining, rehabilitation and closure costs required for the NGP for a mine life that spans 11 financial year periods, with a processing production rate of +5.0 Mt/a. Project capital costs are summarised in Table 1.

Table 1: NGP life of mine capital cost summary (Q4CY2024, -10/+15%)

COST ELEMENT US$M

Development and Pre-Production Capital 523.1 Sustaining Capital 97.1 Rehabilitation and Closure Capital 58.8

LOM Project Total 679.1

The development and pre-production capital cost of US$523.1 million includes process plant, mine services area and infrastructure costs necessary to commence production, as well as operational readiness and capitalised pre-production costs. The development and pre-production capital cost includes costs incurred post-FID up to first gold pour. The development capital cost includes construction distributables, EPCM management costs, owner’s costs, commissioning spares, the initial stage of the TSF, taxes (withholding and duties) and contingency. The pre-production capital cost includes operational readiness labour and programs, and capitalised pre-production costs for mining, processing and General and Administrative costs (G&A). The development and pre-production capital cost is summarised in Table 2. The development and pre-production capital cost estimate, considered to have an accuracy of -10/+15%, is based on information obtained during the fourth quarter of calendar year 2024 (Q4 CY24).

Table 2: NGP development and pre-production capital cost summary (Q4 CY24, -10/+15%)

COST ELEMENT US$M

Process Plant 117.8 Reagents and Services 38.3 Infrastructure General 93.7 Mining Services and Mining Contractor Establishment 11.0 Construction Distributables 27.5 EPCM Management Costs 51.2 Owner’s Project Costs 80.9 Taxes (WHT) 2.5 Development Capital Contingency 49.3 Operational Readiness 11.0 Capitalised Pre-Production – Mining 33.1 Capitalised Pre-Production – Processing 4.5 Capitalised Pre-Production – G&A 2.3

Project Total 523.1

The LOM sustaining capital cost estimate of US$97.1 million includes expenditure required during the life of the operations to maintain production at the specified capacity. Table 3 provides a summary of sustaining capital costs.

Table 3: NGP life of mine sustaining capital cost summary (Q4 CY24, -10/+15%)

COST ELEMENT US$M

Mining 26.4 Processing and Infrastructure 16.5 Tailings and Water Management 54.2

LOM Project Total 97.1

Rehabilitation and closure costs of US$58.8 million include costs to address the reclamation and rehabilitation of land, support socio-economic activities for the local communities, demobilisation of the mining contractor, and provision of statutory and other benefits to employees.

Capital estimate pricing has been derived from a combination of the following sources, including:

• Budget or tender pricing from vendors or recent historical pricing for equipment, materials and rates
• Benchmarking of expatriate and local labour rates and
• Allowances

OPERATING COST ESTIMATE

The LOM operating cost summarised in Table 4 has been estimated by utilising an operating cost model that incorporated input costs derived from the mining schedule developed by Perseus, mining costs developed by a third-party mining consultant, the plant feed schedule developed by Perseus, the processing costs developed by a third-party engineering group and the G&A, selling and royalties costs developed by Perseus.

Table 4: NGP life of mine operating cost summary (Q4CY2024, ±15%)

COST ELEMENT	US$M	US$/t ORE	US$/oz
Mining	1,179.0	22.66	586
Processing	667.1	12.82	332
G&A	235.9	4.53	117
Revenue Costs*	319.7	6.08	157
LOM Project Total	2,401.8	46.10	1,192

• Revenue Costs includes doré transport and refining costs, royalties, and levies

The mining cost of $22.66/t of ore is equivalent to $3.41/t of material (ore + waste) mined.

FINANCIAL EVALUATION

The financial evaluation has been completed on a 100% project basis and has been considered across a range of gold prices. Table 5 presents key economic inputs for the financial evaluation.

Table 5: Key economic inputs

ITEM VALUE

Fuel price US$1.121/L Grid power unit cost US$0.07/kWh Discount rate 10% Tanzanian Government royalty 6% Inspection fee 1% Service levy 0.3% Corporate tax rate 30% VAT rate 18%

At a gold price of US$2,100/oz, pre-tax NPV10% is US$404 million with an IRR of 25.6%. Post-tax NPV10% is US$202 million with an IRR of 19.0%. The Project generates average pre-tax cash flows of US$101M/a over the 11 financial years of operation. The average pre-tax AISC of gold production is US$1,211/oz and pre-tax All in Cost (AIC) is US$1,536/oz, which includes initial capital costs and mine closure costs. Table 6 summarises the NGP financial evaluation across a range of gold prices.

Table 6: Life of mine financial summary^*

UNIT US$2,400/oz US$2,700/oz CATEGORY ITEM US$2,100/oz

Revenue US$M 4,285 4,889 5,492 Development and US$M 523 523 523 pre-production Capital Sustaining US$M 97 97 97 Rehabilitation and US$M 59 59 59 closure

Net Project Cash Pre-tax		US$M	1,133	1,692	2,251
Flow	Post-tax	US$M	706	1,089	1,471
	Pre-tax	US$M	404	707	1,010

NPV10% Post-tax US$M 202 410 617 Pre-tax % 25.6 35.7 44.9 IRR Post-tax % 19.0 27.1 34.4

• All figures quoted on 100% basis

Cumulative pre-tax net cash flow across a range of gold prices is shown in Figure 7.

Figure 7: NGP pre-tax cumulative net cashflow

Figure 8 shows key sensitivities for the NGP economics, based on a gold price of US$2,100/oz. Note that the economics of the NGP are most sensitive to variations in gold price.

Figure 8: Key sensitivities to NGP pre-tax NPV (US$2,100/oz)

PROJECT IMPLEMENTATION AND SCHEDULE

Figure 9 summarises key activities in the NGP implementation schedule. Pre-commitment funding has supported activities up to this FID announcement. Project execution will commence immediately, targeting production of first gold in Q1 CY2027.

Figure 9: Project implementation summary schedule

The critical path for the NGP, as shown in Figure 10, runs through the supply and installation of the mills, followed by installation and energisation of the permanent power supply. The contract for the supply of the mills was awarded to Metso Australia in late 2024, and the Power Supply Agreement with TANESCO has concluded and is ready to be executed.

To further reduce schedule risk, Metso Australia was awarded the crusher package in early 2025 to advance detailed design and accelerate the project timeline.

Figure 10: Project critical path

Construction of the RAP housing is well progressed, with Priority 1 Project Affected Persons from the permanent camp and process plant areas already relocated to their new homes.

Early Works Construction activities commenced late last year and include site establishment, installation of temporary construction accommodation, and bulk earthworks for the SML perimeter fence line, permanent camp and process plant areas. Additionally, procurement of key equipment and materials has progressed to bolster Perseus’s self-perform capabilities.