• Conceptual underground mine plan stopes of 5.2Mt @ 2.1g/t Au and 6.5Mt @ 2.2g/t Au beneath Diucon and Eagle open pits
• Conceptual underground mine plan stopes of 46.5Mt @ 2.2g/t Au beneath all Hemi open pit designs
• Potential for two separate declines to access underground mineralisation

De Grey Mining Ltd has presented the outcomes of its Hemi Underground Mining Conceptual Study, which concludes that there may be potential for underground mining at Hemi and presents a strong case for further studies. The study was conducted on the November 2023 Hemi Mineral Resource Estimate and assessed the amenability of the entire Hemi Mineral Resource to underground mining, as well as the Mineral Resources beneath the Diucon and Eagle open pit designs. The results indicate conceptual underground mine plan stopes of 5.2Mt @ 2.1g/t Au for 355,000oz and 6.5Mt @ 2.2g/t Au for 460,000oz beneath the Diucon and Eagle open pit designs, respectively. For the entire Hemi Mineral Resource, the study identified conceptual underground mine plan stopes of 46.5Mt @ 2.2g/t Au for approximately 3.2Moz of contained gold. The study also assessed decline access options from surface to allow the potential for contemporaneous open pit and underground mining at Hemi, with two separate declines being considered. The underground mining methods could comprise sub-level caving and/or sub-level open stoping, with stope widths varying from approximately 10 to 25m. The study has been successful in demonstrating the potential to support underground mining concurrently with open pit mining at Hemi, which could introduce additional flexibility during the operations phase.

Further wide-spaced step-out drilling at Hemi to confirm extensions to mineralisation, Mineral Resource infill drilling at Eagle, and continuing studies to progress the assessment of underground mining potential.