The bauxite deposit at Weipa, in north Queensland, is a 2 to 6 m thick pisolithic bauxite overlying a lateritic weathering profile about 30 m deep.

The bauxite overlies two different substrates. On the Weipa Peninsula, Tertiary fluvial sands and clays of the Bulimba Formation form the substrate, whereas on the Andoom Peninsula the substrate is glauconitic marine sediments of the Normanton Formation, a part of the Rolling Downs Group. The major difference between the two regions is the presence of quartz at Weipa and its absence at Andoom.

The lateritic profile at Weipa follows the classic sequence from bedrock though saprock and saprolite to a plasmic (pallid or bleached) zone, up to a mottled zone having a ferruginous duricrust of variable cementation at its top. Above the duricrust is the lateritic gravel—the bauxite. The bauxite is entirely pisolithic and oolithic, with only sporadic cementation of these particles. Consequently the bauxite is loose and is free-flowing whenever a vertical edge is created. The base of the bauxite (top of the lateritic duricrust or iron-stone) coincides with the top of the wet season watertable. Soils over the bauxite are grey-brown sandy loams with a very thin A-horizon and a redbrown to yellow B horizon. Locally there are yellow podsolic soils.

The Weipa operations consist of two continuous mining operations at East Weipa and Andoom, two beneficiation plants, 19 kilometres of railway to transport mined bauxite to the port area, two stockpiles and two ship loaders.

Bauxite ore in Weipa is found in a layer three to four metres deep in the form of small, red pebbles, called pisolites.

Vegetation is removed from the site to be mined and scrapers strip the topsoil (which varies in depth from one to ten metres). Front-end loaders use a shallow, opencut technique to load the bauxite, which lies below the topsoil, into bottom-dump trucks that carry the ore to the dump station. The bauxite is then transported to the beneficiation plant by rail or conveyor.

At the beneficiation plant, the ore is screened and washed, then placed into stockpiles prior to loading onto ships.

The bauxite is washed and screened at the beneficiation plants. Once washed, the ore becomes ‘product’ and is stored on stockpiles. Andoom product is transported to the stockpiles by train.

Weipa bauxite mined by Rio Tinto in Queensland Australia is pisolitic, with the silica level (both kaolinitic and quartz) decreasing with increasing pisolite size. The beneficiation plant operated by Rio Tinto “wet” screens at a specific pisolite size and the undersize (tailings) are rejected. The cut-off size of ~1.7 mm (Weipa ore) and ~0.4 mm (Andoom).