Tailings management at Olympic Dam involves the monitoring and control of solid and liquid components of the tailings slurry. Tailings slurry is deposited in thin layers using a spigot system from the perimeter of each cell. The solids settle onto the tailings beach whilst the supernatant liquor is collected from the centre of each cell. The liquor is decanted into evaporation ponds. Additional solids storage capacity is provided by upstream raising of the perimeter embankments. This involves construction of embankments partly over the previous embankment and partly over dried tailings. A portion of the coarse fraction of the tailings is separated using hydrocyclones for use underground in cemented aggregate fill (CAF). A new tailings disposal system is being considered for use at Olympic Dam. The system, called Central Thickened Discharge (CTD), involves the deposition from a number of central risers to form a series of intersecting cones. Field trials will be carried out to confirm design parameters and further evaluate the viability of the system for use at Olympic Dam.
Engineers Australia members participating in AGS technical sessions can record attendance on their personal CPD logs. Members should refer to Engineers Australia CPD policy for details on CPD types, requirements and auditing guidelines.