The spill occurred when a piece of steel passed the trash screen and entered the cyclone system, creating a blockage. The HMI alert did not allow enough time for the operator to shut down the process before the overflow occurred. Most of the spill was contained within the building, however approximately 15 m3 of slurry migrated out the door onto the industrial pad. Following the investigation into the cause it was determined the piece of steel had been in the ore as it entered the process. To prevent reoccurrence, a large magnet is being installed to remove such objects.