Vertex Minerals Advances Mechanised Stoping Trial at Reward Gold Mine with High-Grade Results

Mechanised Longhole Stoping Trial Kicks Off at Reward Gold Mine

Vertex Minerals (ASX:VTX) has reached a significant operational milestone with the first production firing of its trial mechanised longhole open stope at the Reward Gold Mine in New South Wales. Targeting the high-grade Mica 1 lens, the stope was mined at a narrow width of approximately 1.2 metres, a notable departure from the previous 4-metre wide stopes that diluted ore grades substantially. This narrow mining approach is among the tightest mechanised longhole stopes reported in Australia, aiming to deliver higher-grade feed to the processing plant.

Early Ore Quality and Production Estimates

Initial screening of ore from the 1,200-tonne stope revealed high-grade quartz with visible gold, consistent with expectations for the Mica 1 lens. Vertex anticipates a diluted head grade to the plant of approximately 8 grams per tonne of gold. While these figures are preliminary and based on current geological models rather than confirmed mineral reserves or laboratory assays, they suggest a meaningful uplift in ore quality compared to historical mining methods.

From Airleg to Mechanised Mining: A Strategic Shift

The trial marks a strategic pivot away from the manual airleg mining method previously used at Reward, which, while selective, was limited in productivity and mechanisation. Vertex is deploying mechanised longhole stoping drilled initially with a modified jumbo rig and, from mid-September 2026, with a dedicated Resemin Muki longhole rig specially configured for the mine’s narrow drives. This shift is expected to enhance drilling accuracy, reduce dilution, and improve productivity and cost efficiency as the mine matures.

Overcoming Ground Condition Challenges

Progress to the first stope was delayed due to poor ground conditions caused by approximately 14 years of inundation before dewatering. The company undertook extensive remediation, including rock bolting, mesh installation, and grouting to secure the underground workings. These safety measures were essential before mining could safely proceed, illustrating the operational challenges inherent in revitalising historic underground infrastructure.

Infrastructure Upgrades to Support Mining Efficiency

In addition to the new longhole rig, Vertex has modified rail sets on its jumbo drill rigs to allow development of smaller drive dimensions, which is expected to reduce dilution by over 20% for equivalent cut lengths. The mechanised approach, combined with remote-controlled loaders for stope mucking, aims to streamline stope delivery times, reduce waste, and improve the quartz-to-waste ratio feeding the ore sorter and plant, thereby potentially lowering tailings generation.

Operational Outlook and Management Commentary

Executive Director Operations Jim Simpson described the trial as "a pivotal moment in the Reward Mine’s evolution," highlighting the benefits of mining narrow, high-grade veins with minimal dilution. He emphasised the importance of the operating data being gathered to plan the wider rollout of mechanised longhole stoping as additional levels are developed below Decline 3. The commissioning of the Resemin Muki rig in mid-September is expected to further enhance drilling accuracy and production efficiency.