Estrella Resources has completed a Category B market appraisal at its Ira Miri manganese project, confirming a 27,371 tonne stockpile including nearly 5,000 tonnes of high-grade manganese. Exploration upside remains significant with open mineralisation and upcoming geophysical surveys.
- 27,371 tonnes manganese stockpile with 4,984 tonnes at 49.38% Mn
- In-situ sampling confirms ultra high-grade mineralisation up to 60.22% Mn
- Mineralisation remains open below pit floor and along pit walls
- Shipment preparations and export approvals underway
- Further IP geophysical surveys and drilling planned to define resource scale
High-Grade Stockpile Confirms Rapid Progress
Estrella Resources Limited (ASX:ESR) has marked a significant milestone at its Ira Miri manganese project in Timor-Leste, completing a Category B market appraisal extraction programme that yielded a surveyed stockpile inventory of 27,371 tonnes. Notably, this includes 4,984 tonnes of high-grade manganese grading 49.38% Mn, with in-situ pit sampling revealing ultra high-grade mineralisation up to 60.22% Mn. The stockpile remains within the approved 30,000 tonne limit, underscoring the company's ability to advance swiftly from maiden drilling in May 2025 to a sizable bulk sample in under a year.
Mining operations confirmed a structurally complex manganese system hosted within the Noni Formation, revealing folded and faulted manganese pods. The mineralisation remains open beyond the current pit boundaries, including beneath the pit floor and along pit walls, with multiple untested high-priority Induced Polarisation (IP) geophysical anomalies at depth offering substantial exploration upside.
Product Flexibility and Shipment Preparation
The market appraisal sample has been categorised into high, medium, medium-low, and low-grade stockpiles, providing Estrella with product optionality to meet customer specifications. Ongoing sizing and yield studies aim to optimise pre-shipment product specifications, while efforts to comply with International Maritime Solid Bulk Cargoes (IMSBC) Code and other shipment preparations are advancing. Export and trans-shipment approvals are progressing in tandem, positioning Estrella for imminent product dispatch.
Mining was conducted over approximately 42 operating days without blasting, moving around 108,000 tonnes of waste alongside the ore. The pit floor remains mineralised and accessible despite wet-season conditions impacting lower-pit access towards the campaign's end.
Geophysics and Follow-Up Drilling to Expand Resource
Estrella plans to deploy expanded IP and resistivity surveys in late May to early June to delineate the scale and depth extent of the Ira Miri manganese system. These surveys will inform follow-up drilling targeting priority geophysical anomalies beneath the pit floor and along strike, supporting a potential Category A Mining Licence application. The company also intends to accelerate regional exploration around Ira Miri, including targets like Lalena, Daudere, Soru, and Sica, with additional focus on gold and copper prospects nearby.
This operational update builds on Estrella’s recent capital strengthening efforts, including an $8 million underwriting deal to support option exercises, which bolster the company’s financial position ahead of advancing Ira Miri. Meanwhile, resource development at the Werumata Limestone Project continues apace, with ongoing modelling expected to yield a maiden JORC limestone resource soon, complementing Estrella’s diversified mineral portfolio as detailed in its Werumata exploration progress.
Technical Rigor Underpins Results
Estrella’s geological team employed rigorous sampling and assay protocols, including in-situ bulk density measurements using an excavation and water-fill method, and laboratory XRF fusion assays conducted in Jakarta. The measured bulk density and tonnage reconciliation confirm the stockpile inventory’s accuracy and compliance with regulatory limits. The company also maintains strong local partnerships and government engagement, exemplified by a recent ministerial site visit and presentation of a massive manganite boulder to the Timor-Leste Ministry of Petroleum and Mineral Resources.
Bottom Line?
Estrella’s Ira Miri project is transitioning from exploration to near-term production, but the timing and success of export approvals and further drilling will be critical to unlocking full resource potential.
Questions in the middle?
- How will upcoming IP surveys refine the scale and continuity of the Ira Miri manganese system?
- What are the key challenges in securing Category A Mining Licence approval for Ira Miri?
- Can regional exploration around Ira Miri yield additional manganese or base metals to enhance project economics?