Alumina Limited invests in bauxite mining, alumina refining and selected aluminum smelting operations. The Company's business undertaking is in the global bauxite, alumina and aluminum industry, which it conducts principally through bauxite mining and alumina refining, with some minor alumina-based chemicals businesses, aluminum smelting and the marketing of those products. The Company conducts these business activities through its joint venture, Alcoa World Alumina & Chemicals (AWAC). AWAC is a producer of alumina and miner of bauxite. AWAC operates mines integrated with alumina refineries in Western Australia and Brazil. Other refineries operate in Spain and Texas in the United States. AWAC's bauxite deposits are extracted by open cast mining from strata, typically 4 to 6 meters thick under a shallow covering of topsoil and vegetation. The topsoil is removed and stored for later use in restoration of the forest. AWAC supplies bauxite ore to Pinjarra and Kwinana Refineries.