FGM’s processing plant crushes rock from the underground mine using a jaw crusher. This rock is then further reduced in size by a mill, a 2-storey revolving cylinder that lifts the rock up and then drops it back on itself in a continuous manner. SAG stands for Semi-Autogenous Grinding, a type of mill that utilises steel balls to assist with breaking and grinding the rock down to less than 1 mm size profile. The SAG mill allows for the ‘liberation’ of small gold particles for recovery in other elements of the processing circuit.
FGM processing plant SAG mill
Recent acoustic investigations conducted on site, identified the SAG mill as a significant noise source within FGM’s processing plant and a key item for additional noise attenuation.
In response to this recommendation, FGM is progressing plans to install a soundproof enclosure around the SAG mill. Dubbed the ‘SAG Mill Sound Attenuation Project’ this project is currently in the scoping and design stage, with a 30% design review already complete.
After completing a competitive tender process between multiple contractors, EMtek were awarded the principal contract, opting to use J.C Butko Engineering for construction (both Victorian businesses). Key features of the design are removable hatches in the roof so to not obstruct access for maintenance, use of acoustically engineered soundproof panels on the enclosure, inspection walkways on the roof, with various monorails to be installed internally.
Because the SAG mill runs continuously (24/7), scheduling the timing for construction of the project will be critical to minimise operational impacts. The construction risk assessment identified a building method, which could be scheduled during a planned maintenance shutdown of the SAG Mill (a 1.5-day stoppage). During construction, the SAG mill will be completely scaffolded so that work can commence around it. The project is scheduled to be completed by July 2022.
This project forms part of FGM’s ongoing program of continuous improvement in relation to noise management and abatement. This project will compliment the recently completed BIOX Blower Sound Attenuation Project
SAG Mill Noise Attenuation Project Design