Resource Upgrade Raises Questions on Mining Feasibility and Regulatory Approvals

Resource Upgrade and Data Integration

Yari Minerals Limited (ASX – YAR) has announced a significant 26% uplift in the JORC (2012) Inferred Coal Resource at its Rolleston South Coal Project in Queensland’s Bowen Basin. The resource now stands at approximately 190 million tonnes, up from 151 million tonnes reported earlier this year. This upgrade was achieved by integrating drilling data from three coal seam gas wells obtained through a data sharing agreement with State Gas, expanding the geological modelled area, improving coal seam thickness estimates, and extending the cut-off depth from 450 metres to 550 metres.

Geological and Technical Enhancements

The updated resource model incorporated data from 24 boreholes, including the new coal seam gas wells, and utilised advanced modelling software (Datamine Minescape) with refined parameters such as a reduced modelling buffer and exclusion of groundwater bores to enhance accuracy. The project covers formations within the upper Permian to Cainozoic sequence, with the Bandanna Formation hosting the main coal seams. The resource expansion reflects improved understanding of seam continuity, thickness, and depth, supported by reinterpretation of historical seismic data and downhole geophysical logging.

Quality and Mining Prospects

Coal quality analyses reaffirm the potential for high-grade, low-ash thermal coal suitable for export, with calorific values ranging from 24.33 to 27.98 megajoules per kilogram. Importantly, test-work is planned to assess the potential to classify parts of the resource as semi-soft coking coal, which could significantly enhance the project’s economic value. While no formal mining method evaluation has been conducted yet, the company anticipates a combination of small-scale open-cut mining and underground methods such as bord and pillar or longwall mining.

Infrastructure and Strategic Location

The Rolleston South Coal Project benefits from excellent infrastructure access, including proximity to the Blackwater Rail System (40km by state highway) and the Port of Gladstone (less than 300km away), both critical for coal export logistics. The project is also surrounded by established coal deposits, reinforcing its strategic position within a world-class coal-producing region.

Next Steps and Outlook

Yari’s board is finalising approvals and drill targets for an inaugural drilling campaign aimed at upgrading the resource classification from Inferred to Indicated or Measured and confirming coal quality through metallurgical test-work. This campaign will include a site visit and aims to unlock further shareholder value by validating the semi-soft metallurgical and coking coal potential. Further exploration and development planning are underway to capitalise on both open-cut and underground mining opportunities.