Australia

Darling Range Operation

Click for more information

Categories

Overview

Mine TypeOpen Pit
Commodities
  • Bauxite
  • Alumina
  • Aluminum
Mining Method
  • Truck & Shovel / Loader
Production Start... Lock
Mine Life... Lock
ShapshotDarling Range operation consists of two bauxite mines in Western Australia (Huntly mine and Willowdale mine, which is located 70 km SE from Huntly). The Huntly and Willowdale operations collectively represent one of the world’s largest bauxite mines.
Related Asset

Owners

SourceSource
CompanyInterestOwnership
Alumina Ltd. 40 % Indirect
Alcoa Corp. 60 % Indirect
Alcoa World Alumina and Chemicals (AWAC) (operator) 100 % Direct
The mining rights and assets involved with bauxite mining and alumina refining in Australia are 100% owned by Alcoa of Australia Limited (AofA), an affiliate of Alcoa owned by Alcoa World Alumina and Chemicals (AWAC). AWAC is an unincorporated global joint venture between Alcoa and Alumina Limited. Alcoa Corporation owns 60% and Alumina Limited owns 40% of these entities, directly or indirectly, with such entities being consolidated by Alcoa Corporation for financial reporting purposes.

Contractors

Lock

- subscription is required.

Deposit type

  • Bauxite

Summary:

Bauxite Deposits Lateritic bauxite deposits such as those in the Darling Range of WA generally formed in tropical (hot and humid) environments through chemical weathering. As a result, lateritic bauxite deposits are known to exist across Central and South America, West Africa, Central Asia, and Australia. Bauxite deposits have been identified throughout the Darling Range and generally occur as erratically distributed alumina-rich lenses within the eroded laterites that mantle the granites to the east of the scarp line. The bauxites are thought to have formed from the lateritization of the peneplained surface of the Western Gneiss Terrane rocks. Lateritization is thought to have commenced during the Cretaceous and continued through to the Eocene, with the subsequent periodic activity of the Darling Fault resulting in the current landform of scarps and deeply incised valleys on the western edge of the Darling Range. Mineralization Weathering, alteration and leaching of the granite bedrock has developed the bauxite mineralization which principally occurs as 65% microcrystalline gibbsite Al(OH)3 with minor to rare boehmite ALO(OH), and accessory minerals of 18% goethite FeO(OH), 7% hematite Fe2O3, 9% quartz SiO2, 1% kaolinite/halloysite Al2Si2O5(OH)4, and 0.5% anatase/rutile TiO2. Other minerals within the bauxite that may influence the alumina refinery performance include: • Boehmite: generally occurring below 1%, this can cause premature precipitation of dissolved gibbsite resulting in alumina being lost to the red mud residues. • Organic Carbon: as oxalate, typically less than 0.2%, (2.0 kg/t, measured as Na2C2O4) this can result in reduced digestion efficiencies and cause crystal growth issues during precipitation. • Sulphate: generally occurring at 0.25%, this can consume caustic soda during digestion resulting in lower yields. Property Geology Most of the bauxites display a typical profile comprising the following sequence, from the top down: • Overburden: A mix of soils, clays, rock fragments and humus that is typically 0.5 m deep, but deeper pockets are common. • Hardcap: An indurated iron-rich layer that is usually 1 m to 2 m thick. It is generally high in available alumina (A.Al2O3) and low in reactive silica (R.SiO2). • Friable Zone: A partially leached horizon that usually contains a mix of caprock fragments, clasts, nodules, pisolites, and clays. It is usually a few meters thick but can exceed several meters in places. It is generally high in A.Al2O3 and low in R.SiO2. • Basal Clay: A kaolinitic clay horizon that represents the transition zone between the Friable Zone and the underlying saprolitic material. It is generally high in R.SiO2 and low in A.Al2O3. The Hardcap and Friable Zone are targeted as the ore horizon. Selective mining practices are applied to minimize the inclusion of Overburden, because of its elevated organic carbon levels, and Basal Clay because of its elevated R.SiO2 concentrations. Within the Hardcap and Friable Zone, the dominant minerals, in order of abundance, are gibbsite, quartz, goethite, kaolinite, and hematite, with lesser amounts of anatase and muscovite.

Reserves

Lock

- subscription is required.

Mining Methods

Lock

- subscription is required.

Comminution

Crushers and Mills

Lock

- subscription is required.

Processing

Lock

- subscription is required.

Production

CommodityUnits2022202120202019201820172016
Bauxite M dmt  ....  Subscribe  ....  Subscribe  ....  Subscribe35343332
All production numbers are expressed as ore.

Operational metrics

Metrics2022202120202019201820172016
Annual milling capacity  ....  Subscribe
Annual production capacity  ....  Subscribe  ....  Subscribe  ....  Subscribe8,979 kt of alumina powder8,979 kt of alumina powder8,979 kt of alumina powder8,979 kt of alumina powder
Annual production capacity  ....  Subscribe  ....  Subscribe  ....  Subscribe358 kt of aluminum metal358 kt of aluminum metal358 kt of aluminum metal358 kt of aluminum metal

Production Costs

Commodity production costs have not been reported.

Heavy Mobile Equipment

Lock

- subscription is required.

Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Oct 4, 2023
....................... Subscription required ....................... Subscription required Subscription required Oct 4, 2023
....................... Subscription required ....................... Subscription required Subscription required Oct 4, 2023
....................... Subscription required ....................... Subscription required Subscription required Oct 4, 2023

EmployeesYear
...... Subscription required 2022
...... Subscription required 2021

Aerial view:

Lock

- subscription is required.