Mapping South Australia’s big mines and new projects

JP Casey 9 December 2019 (Last Updated December 9th, 2019 11:43)

South Australia is home to a number of massive mining operations, from significant uranium projects to the world’s largest zircon mine. The state also boasts a number of exciting new mining developments, including a project that aims to be the world’s largest graphite mine. We map out the established projects and those on the horizon.

Mapping South Australia’s big mines and new projects
Today, Olympic Dam is the largest mine in Australia and the world’s largest single deposit of uranium. Credit: BHP

Mines in operation

Olympic Dam

This BHP-owned project comprises above ground and underground operations, and boasts more than 450km of underground roads and tunnels to help miners access deposits of copper, gold, silver and uranium. While production was hindered by a series of smelter maintenance projects between 2017 and 2018 that saw production fall to 135,000 tonnes per year, BHP has planned a series of ambitious expansion projects that will see annual production more than double to 330,000 tonnes.

Despite these setbacks, the mine remains the state’s largest producer of uranium, with annual production reaching 3.364 tonnes in 2018, a slight decline from the 4,363 tonnes produced in 2016 but a substantial figure regardless.

Prominent Hill

While smaller in scale than the Olympic Dam, Oz Minerals’ Prominent Hill mine also featured open pit and underground operations. While the Malu open pit mine was eventually closed in the first quarter of 2018, work continues at the project’s underground mine, alongside underground operations at the Ankata region.

The mine produced 139,000 tonnes of copper between July 2017 and June 2018, and 179,000 ounces of gold, with open pit operations leading in both minerals. As a result, the future of the mine is somewhat uncertain, with the closure of the productive open pit operations posing a threat to production.

However, Oz Minerals has consistently increased its estimations of the mine’s ore reserves; the mine was estimated to have less than 10 million tonnes of ore in 2013, but this has increased to 57 million tonnes of proven resources, alongside a further 12 million tonnes of probable deposits. This has helped increase the mine life until 2029, and suggests that an entirely underground operation at Prominent Hill could yet be profitable.

Four Mile

While the Olympic Dam project is the state’s largest uranium producer, the Quasar Resources-owned Four Mile project is the state’s only mine that exclusively produces the radioactive material, following the closure of the Honeymoon mine in 2013. Annual production at the mine increased steadily from 186 tonnes in 2013-14 to 1,615 tonnes two years later, before a slight decline in productivity saw production reach 1,430 tonnes in 2016-17.

The mine has been dogged by conflict involving its owners, Quasar, which owned 75% of the project, and Alliance Resources, the junior partner in the joint venture. In 2015, Quasar refused to sell the mined uranium, choosing to stockpile the resource and wait for increases to the uranium price, which deprived Alliance of income it considered to be owed; Alliance eventually took Quasar to the Supreme Court of South Australia over the dispute, which ended with Quasar agreeing to purchase all of Alliance’s shares in the project for A$74m in July 2015.

Jacinth-Ambrosia

The Iluka Resources-owned project is South Australia’s only mine currently producing heavy minerals, such as zircon and ilmenite, through sand mining. The mine produced close to half a million tonnes of these materials in 2018 according to the state’s Department for Energy and Mining, close to the mine’s total capacity.

The mine’s deposits contain around 9.5 million tonnes of heavy minerals at a grade of 6.5%, with close to half of this mass made of zircon, a mineral often used in the manufacture of ceramics, making Jacinth-Ambrosia the world’s largest zircon mine. Despite the potentially devastating impacts of sand mining, the mine is located within the Yellabina Regional reserve, as it is the state’s first mine to operate under what Iluka calls the government’s “mixed use regional reserve policy”, which gives the state government oversight with regards to the mine’s environmental management and indigenous employment policies.

 

Discoveries, developments and rehabilitation

Central Eyre

Developed by Iron Road, the Central Eyre project will be the state’s only mine that will produce magnetite, a mineral typically found in iron ore that can be used to separate coal from waste material, giving the project significant potential for involvement in the mining supply chain. The company first sought approval for the mine in 2015, which was granted following two years of state government assessments and public feedback.

The mine is expected to produce 21.5 million tonnes of magnetite each year over a lifespan that could reach 30 years, according to Iron Road’s latest annual report. Around 2,700 jobs are expected to be created in construction and operation, with the project expected to make a significant impact on local communities. Having invested A$4.5bn into the project, Iron Road will be hoping that the mine can live up to its lofty potential.

Wilgerup

Sharing the Central Eyre peninsular is the Wilgerup project, a similarly specialised mine that will exclusively produce hermatite. This ore comprises much of the iron orebodies that are mined around the world, and has a secondary use in the manufacture of gemstones. Originally developed by Centrex Metals, production was put on hold due to the company’s inability to construct the transport infrastructure required to move the minerals 110km via road to Spencer Gulf for export.

The licence was purchased, along with the Kimba Gap project, by SIMEC Mining for just A$10m in royalty payments, and there is optimism that the major will be able to develop the mine to a point where operations can begin, and the project can live up to its promised production of up to 1.5 million tonnes of hematite per year.

Siviour Mine

A third project based on the southern Eyre Peninsular, the Siviour project aims to be the state’s largest graphite mine by production. Targeting 142,000 tonnes of graphite per year, this would put the A$185m project ahead of the 140,000 tonnes targeted by Campoona, and the 35,000 tonnes estimated at Kookaburra Gulley, another two graphite projects to have received licences on the peninsular.

Construction work is scheduled to begin in late 2019, and production is expected to begin one year later and last for up to 30 years. The total ore reserves of the project are just over 45 million tonnes, 3.6 million tonnes of which contain graphite. The project has also been partially funded by the Atradius, the Dutch export credit agency, with the organisation funding around 60% of the construction and maintenance costs.

Hillside Mine

Located on the southern edge of the Pine Point Copper Belt on the state’s Yorke Peninsula, Rex Minerals’ Hillside project has the potential to be one of Australia’s largest open pit copper projects. With proven and probable resources totalling just over half a million tonnes of copper, and close to half a million ounces of gold, the project has significant potential; although originally envisioned as a copper-gold-iron project, falling commodity prices in 2014 encouraged Rex to streamline its operations, and focus only on copper and gold production.

The company’s new plan is to construct a mine with a lifespan of at least 13 years, which will process around six million tonnes of ore per annum, including 35,000 tonnes of copper and 24,000 ounces of gold. Despite an investment of A$480m, the company expects to see a return rate of at least 14% on this initial expenditure.

Leigh Creek

The Flinders Power-owned operation is the only former coal mine in the state currently being rehabilitated. Following 71 years of operations between 1944 and 2015, during which time around 100 million tonnes of coal was produced from the open pit mine, Flinders’ parent company Alinta Energy ceased operations when they were no longer profitable.

Since the mine’s closure, Flinders has worked with a number of relevant parties, including local businesses and the Adnyamathanha Traditional Lands Association, which represented the interests of aboriginal people, to develop a rehabilitation plan. The project focuses on ensuring local water quality is not disrupted by the operations, including both streams and groundwater reserves, and minimising the risks of coal seams spontaneously combusting. However, it is difficult to gauge the effectiveness of the rehabilitation work, as they aim to ensure the long-term health of the environment, and many of these projects are in their infancy.