Sunrise Dam Gold Mine is
located in a semi-desert region, about 200 km northeast of Kalgoorlie in
Western Australia. The mine has been operating since 1997, with ATC Williams
involved in design and operational assistance with the tailings storage at this
site for the entire period.
Example of early use of central thickened discharge
ATC Williams (then MPA Williams) previously worked with the owner, AngloGold Ashanti on their Union Reefs mine in NT. We were commissioned to undertake the design of the tailings storage for Sunrise Dam at the planning stage.
The original tailings dam was a conventional paddock style storage. However, after initial start-up, a system based on the concept of central thickened discharge (CTD) was quickly introduced. The CTD has operated since 1999 and has provided significant cost savings, as it avoids the requirement for continual perimeter raises associated with paddock storages.
Designed for water recovery
The original CTD design
comprised a cone approximately 2 km in diameter, with a low perimeter wall.
Bleed water and rainfall runoff are collected into a lined pond on the low side
of the storage and recycled. A seepage interception drain was added around part
of the perimeter and recovers up to 10% of the returned water. All the
recovered water is recycled to the plant.
Recent lifecycle enhancements
Throughout the life of the TSF there have been a series of small perimeter raises and lifts to the pipeline access ramp.
As the storage has filled, ATC Williams has worked closely with the process operators to optimise the depositional arrangements with a resulting progressive increase in beach slope and capacity (see images below).
This work is based on the outcome of fundamental research into beach deposition and slope prediction modelling undertaken by ATC Williams (with some of the associated fieldwork carried out at the site). The fundamental insight is that splitting the discharge (to achieve lower flow rates at each outlet) will result in a steeper beach slope.
Following continuing increases in the planned mine life, the CTD footprint finally needed to extend significantly. We have achieved this by stepping out the perimeter by about 800m to the south-east.
We acknowledge the senior staff currently involved in the project:
Keith Seddon (Senior Principal)
Peter McGough (Principal Engineer, Tailings
Dr Behnam Pirouz (Principal Engineer, Slurry Rheology)