The Moolarben open cut and longwall, commissioned November 2017, produced a record 16.5 million tonnes of saleable coal in 2018.
"Moolarben is a world-class tier one thermal coal asset," Schmidt said in a company presentation.
"It is integrated operation of two mines - one open cut and one underground - after successful underground expansion in 2017."
The integrated Moolarben Coal Complex has approval to produce up to 21Mt of run-of-mine coal per annum.
However, Schmidt said Moolarben had further scope for expansion.
"The company could increase on-site RoM coal production from 18Mtpa to 24Mtpa through optimising the approved … operations," he said.