Whitehaven Coal has released a yearly update to its coal resources and coal reserves for 2023.
The miner has announced a decrease in coal resources for Maules Creek in Tarrawonga and Werris Creek in New South Wales due to mining depletion.
Narrabri North in NSW also saw decreased coal resources due to sterilised coal for geotechnical stability and un-mined roof and floor within the mining area due to coal quality, in addition to mining depletion.
Recoverable and marketable coal reserves for the three sites also decreased due to mining depletion.
Revisions have been made to the reserves for the Maules Creek open-cut mine to align bypass and yield assumptions with actual performance.
The decrease in marketable reserves at Maules Creek is due to an increase in the proportion of washed coal in the mine plan.
By washing more coal the mine can produce a lower ash and higher energy product that maximises the economic output for the remaining coal reserves when compared with a lower wash option.
Total coal resources for the NSW Vickery resource have not materially changed from its last estimate update in 2015.
However, the 2023 estimate has recategorised some resources to apply a standardised relationship between borehole spacing and resource confidence.
The majority of this recategorisation was reducing the confidence levels of potential underground resources to ‘inferred’.
Revisions have been made to the Vickery open-cut mine reserves to account for work that has been undertaken as part of the ongoing feasibility study including pit shell adjustments, changes to loss and dilution assumptions and coal quality studies.
Recoverable reserves for the mine have reduced from 200 million tonnes to 174 million tonnes.
The updated coal resources and reserves list follows Whitehaven’s confirmation yesterday that the company is currently in line to acquire BHP’s Daunia and Blackwater metallurgical coal mines in Queensland.