The miner said the only remaining step in its commissioning process now is to feed ore through the plant, which managing director Wayne Taylor said is expected to occur in the next few weeks as the hydraulic mining and underground activities are well positioned for the transition.

Once the plant's commissioning has been achieved, Heron will officially transition to a producer of base metal concentrates.

"It is always exciting to reach project milestones, especially as we fast approach the end of the project build process," Taylor added.

Woodlawn, which Heron owns 100%, is located southwest of Sydney. It has an initial 9.3-year reserves-based mine life and will produce zinc in concentrate, copper in concentrate and lead in concentrate, along with associated gold and silver.