Weipa bauxite was first reported in the late 1700s in remote north Queensland, about 600km by air from Cairns. Geologist Harry Evans was responsible for the delineation and development of the Weipa resource in 1955 and commercial mining began in 1961. Rio Tinto owns 100 percent of the Weipa bauxite mine, which has indicated ore reserves of around 1.2 billion tonnes in an area of approximately 2,500 sq km.
Weipa bauxite ore occurs naturally in pisolitic (pealike) form. The bauxite consists mainly of 55 percent aluminium trihydroxide (also called gibbsite) and 14 percent aluminium hydroxide also called boehmite.
Front-end loaders use a shallow, open-cut technique to extract and load the bauxite into bottom dump trucks that carry the ore to the dump station. Conveyors or rail transport are then used to move the bauxite to the beneficiation plant, where the ore is screened, washed and then placed into stockpiles prior to loading onto ships.
Annual production is around 16.3 million tonnes per annum, with most of the mined bauxite shipped to Queensland Alumina Limited (QAL), and Rio Tinto’s Yarwun Alumina Refinery.
Vegetation is recovered from the site before it is mined. After removal of the ore the land is recontoured and re-planted with indigenous vegetation. Rio Tinto’s long term aim is to achieve a ratio of land disturbed to land rehabilitated of 1:1.