De Grey Mining has updated the mineral resource estimate (MRE) for its Hemi gold project in the Pilbara region of Western Australia.
Hemi’s MRE now stands at 264 million tonnes (Mt) at 1.3 grams per tonne (g/t) of gold for 11.2 million ounces (Moz), representing a 1.3Moz increase from Hemi’s maiden MRE released in June 2021 and a 0.7Moz increase from Hemi’s previous MRE released in November 2023.
Hemi’s measured resources have grown by five per cent and its indicated resources 56 per cent since June 2021.
The new Hemi MRE is based on 591 diamond drill holes for 191,430 metres and 1497 reverse circulation (RC) drill holes for 289,847 metres completed between February 2020 and October 2024. Since the November 2023 MRE, 58 diamond drill holes for 29,368 metres and 132 RC drill holes for 17,771 metres have been completed.
Hemi’s drilling programs identified opportunities to increase mine life and annual gold production rate from open pit and underground sources, relative to the Hemi definitive feasibility study (DFS) mine plan that comprises open pit mining production from the Aquila, Brolga, Crow, Diucon, Eagle and Falcon deposits.
Hemi’s MRE including the regional deposits has also soared to 310Mt at 1.4g/t gold for 13.6Moz. De Grey said the MRE update reinforces the quality of the Hemi discovery.
“Mineral resource increases continue to be made at the Hemi deposits,” De Grey general manager exploration Phil Tornatora said.
“Deeper drilling at Aquila-Crow has added significant mineral resources to this updated MRE and demonstrates grades and continuity with the potential for underground mining. Deeper drilling confirms that mineralisation continues at depth in all the Hemi deposits, which remain open below the current mineral resource and open pit mine designs.”
Tornatora said a concept study into underground mining at Hemi based on the November 2023 MRE is currently underway and is nearing completion.
“It is satisfying to see the exceptional intercepts returned from the infill grade control drilling at Brolga, confirming the quality and continuity of the Brolga orebody,” he said.
“This has enabled the reporting of a portion of measured resources within the Brolga starter pit corresponding with the first 12 months of mining at Hemi. Our ongoing exploration is targeting strike and depth extensions to the Hemi deposits, new shallow potential resources adjacent to Hemi, as well as new large-scale discoveries at regional prospects including the Egina and Farno JV (joint venture) areas with Novo Resources.”
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