Bauxite

The discovery of bauxite deposits in Western Australia’s Darling Range led to the establishment of a mining industry around Jarrahdale in 1963. During the 1970s mining operations expanded to two other mines at Del Park and Huntly, east of Dwellingup. By 2000 Alcoa mined bauxite in just two locations - Huntly and Willowdale. These mines produce six million tonnes of ore each year.

When mining for bauxite about half a metre of topsoil and overburden is removed and conserved for later rehabilitation, then the next one to two metres of bauxite is drilled and blasted for extraction. Once the ore has been broken, it is loaded onto haul trucks by excavators or front-end loaders and transported to primary crushers at the mines. Bauxite extracted from the Darling Range is a low-grade ore with a content of more than 27 percent aluminium oxide. It takes seven tonnes of bauxite to yield one tonne of aluminium.  When mining began Alcoa constructed the first alumina refinery in Western Australia at Kwinana in Cockburn Sound in 1963. A second refinery was constructed at Pinjarra in 1972, followed by a third at Wagerup, also in the State’s south west. At the end of the twentieth century the alumina refineries at Kwinana, Pinjarra and Wagerup had a combined capacity of 7.3 million tonnes a year, equivalent to some 16 percent of world demand..