Completion of underground sulphide mining and processing operations

Underground mining operations at DeGrussa have been completed, with the depletion of run-of-mine (ROM) sulphide ore from the DeGrussa and Monty Copper-Gold Mines. The final stopes were extracted, hauled to surface and processed in October 2022.

Processing Extension Project

With the completion of underground mining activities, our DeGrussa operations transitioned to process mineralised waste and oxide stockpiles for the period November 2022 to May 2023. The processing extension project was based on the existing DeGrussa flotation circuit with minimal changes, whereby a simplistic approach was adopted to treat stockpiles with oxide reagents. In order to maximise value and economic returns, our team prioritised higher grade and higher recovery stockpiles, before moving to the remnant lower grade and lower recovery stockpiles, while closely monitoring the technical and economic results.

While the processing of these higher grade and higher recovery stockpiles delivered strong financial outcomes, the transition to lower grade and lower recovery stockpiles proved to be more challenging in the June 2023 Quarter. The high clay content of this material significantly impacted metallurgical recovery and throughput rates, and as the economics became marginal, processing operations ceased in late May 2023, and the site transitioned to care and maintenance.

Sales Process

Having considered various alternatives for DeGrussa following the cessation of processing operations in May 2023, during the December 2023 Quarter, Sandfire determined that the retention of DeGrussa will provide the best outcome for all stakeholders and allow our team to establish its rehabilitation credentials.

This decision also means that we will have a meaningful presence in the area for many years to come and we look forward to both rebuilding our relationship and working with the Yugunga-Nya as we undertake the rehabilitation process.