Nolans Tailings Storage Facility
Project Profile: Ravenswood Gold Mine, Tailings Storage Facility, 2020 – 2022 (+)
Ravenswood gold mine is located 120km south of Townsville in northeast Queensland, Australia. The mine produces 180,000 – 210,000 ounces of gold per year, which will make it Queensland’s largest gold producer in 2022. The 160 hectares tailings storage facility is part of the Ravenswood Gold Mine expansion project.
ATC Williams undertook the detailed design and construction of the Nolans Tailings Storage Facility, which involved the expansion and encapsulation of the existing facility.
The project incorporates a staged embankment construction, which introduces a new Tailings Storage Facility, which will ultimately envelop the existing facility to form a single facility.
The facility is designed for process inputs, including tailings from the process plant and dredged tailings relocated from an existing in-pit tailings storage facility.
Beach Slope Development
The tailings beach design is such that the decant pond can be maintained in a minimum state and uses beach slope development to maximise the ultimate storage capacity of the facility.
The design comprises a rock and earthfill zoned embankment, Bituminous Geomembrane (BGM) liner system, decant return water system, and underdrainage return water system. The facility is completely lined over the impoundment area and the upstream face of the embankment.
Decant Return Water System
The decant return water system features an inclined decant structure constructed of upturned box culvert sections, galvanised steel access stairway and handrails, aluminium stop log segments and a guide rail (pictured below).
The decant structure reports to a subterranean concrete-encased decant outlet pipeline through the foundations that direct decant water downstream to a pre-cast collection chamber and pumping system for recirculation to the process plant.
The underdrainage system features a herringbone layout using a proprietary product, promoting tailings consolidation by providing two-way drainage from the base. The underdrainage system transfers consolidation water to the downstream collection chambers for recirculation via a series of outlet structures and buried pipelines.
Project Key Features
- Earth and rockfill perimeter embankment
- Upstream and downstream raised
- Underdrainage system
- Inclined decant structure and return water system
- Bituminous Geomembrane liner (2.2 Mm2 total)
- Crest height – 73 m
- Crest length – 7.5 km
- Total rockfill – 36 Mm3
We acknowledge the senior staff involved in the project:
Andrew Fyans – Senior Associate Engineer
Craig Noske – Senior Principal Engineer
Allan Watson – Senior Principal Engineer