Rio Tinto has upgraded its managed coal reserves for its Hail Creek coal mine in Queensland.
Marketable ore reserves at the mine have increased by 25 million tonnes (Mt), from 60Mt to 85Mt.
Rio said the update is based on a rigorous examination of the mine and operations planning for the Hail Creek project Western Margin including reprocessing of a primary coal stream to introduce an additional thermal coal product into the operations and marketing plan, and analysing a vast dataset over decades including updates from recent prefeasibility study drilling.
The company also said it had transformed the strategic mine planning processes and tools used to estimate ore reserves, and adopting more efficient mineral resource estimation methods.
The increases to the Hail Creek ore reserves have resulted from a broader programme of orebody knowledge and strategic mine planning optimisation at Rio Tinto Coal Australia.
Hail Creek is located in the northern part of the Bowen Basin.
Rio said the deposit has been extensively drilled using a combination of open hole and wireline coring techniques.
Total core recovery in drill core was above 95 per cent for all holes.