The Hillside copper-gold project located near Ardrossan on the eastern side of Yorke Peninsula in South Australia, is owned by Rex Minerals. The mining lease for Hillside, claimed to be the largest known copper deposit in South Australia, was granted in July of this year.
The concept and pre-feasibility studies for the copper-gold project were completed in 2011 and 2012 respectively, and the feasibility study was nearing completion in August.
The Hillside mine is expected to be commissioned in 2016. It will employ both open pit and underground mining methods to produce up to 75,000t of copper, 60,000oz of gold and 1.2 million tonne (Mt) of iron ore a year, over its estimated 15-year mine life.
Hillside mine geology and resources
Mount Margaret Mining Project, Queensland
Mount Margaret Mining Project is part of Xstrata Copper’s Ernest Henry Mining (EHM) operations in Queensland, Australia.
The Hillside mine is located 15km south of Ardrossan on Yorke Peninsula and was discovered in 2008. The copper-gold-magnetite deposit extends from near land surface to depths exceeding 400m.
The deposit comprises of Proterozoic-aged basement rocks occurring beneath the 30m-thick Cainozoic sequence of sediments in South Australia.
The mine was estimated to contain 180Mt of ore reserves grading at 0.52% copper, 0.13g/t of gold and 14.4% or iron as of June 2013. Resources at the mine are estimated to be 337Mt grading at 0.6% of copper, 0.14g/t of gold and 15.7% of iron.
Copper-gold mining and processing of ore
Open pit mining at the South Australian copper-gold mine will involve conventional load, haul, drill and blast methods, while underground mining will be conducted using the sub-level caving (SLC) mining method. The underground operations will be located at two main areas, namely, the North and South Mines that will be accessed by decline systems.
Ore will be processed at the 15Mt a year capacity processing plant located adjacent to the open pit mine, which will house crushing, grinding, flotation and magnetic separation facilities to produce copper-gold concentrates.
Tailings will be treated with conventional magnetic separation method to recover iron ore concentrate.
Transportation of mine concentrates
The copper, gold and iron ore concentrates produced will be sent to the port of Ardrossan via a 12km long underground slurry pipeline. The concentrates will be filtered, washed and stored at the port before being loaded onto ships.
Construction and infrastructure facilities at Hillside mine
Major construction works will involve the installation of the processing plant, slurry pipeline and a waste rock and tailings storage facility. The project also includes the construction of a filtration plant and upgrades to the loading facility at Port Ardrossan.
Power supply for the processing plant will be provided from the 132kV Yorke Peninsula network via a direct connection to the Ardrossan West 132kV substation.
Fresh water required by the project will be sourced from SA Water as part of an agreement made in October 2012.
Contractors involved in the Hillside project
Mining Plus conducted mining studies during the pre-feasibility and definitive feasibility study phases of the Hillside project. Mining Plus engaged Aldam Geoscience to provide hydro-geological consulting services for the project.
AMEC was engaged for metallurgical studies, including the mineral processing test-work as well as the preparation the capital estimates for the installation of the processing plant. ATC Williams was awarded the contract to design the tailings storage facility.
Golder Associates is assisting in the finalisation of the bankable feasibility study. Ground Control Engineering (GCE) was awarded the contract to conduct the mine operation geotechnical studies.
An early contractor involvement (ECI) with Hyundai and AMEC was finalised in the second quarter of this year. The Korean-Australian consortium is in pricing negotiation with Rex to deliver the project under a fixed-price engineering, procurement and construction (EPC) contract.