To improve shareholder returns, in 2016 Alcoa Inc. separated into two public companies, Arconic (a value-added company making high-end aluminum products), and an upstream company -- Alcoa Corp., one of the world's top producers of alumina (aluminum's principal ingredient from bauxite) and aluminum. Alcoa's portfolio comprises of six businesses: Bauxite, Alumina, Aluminum, Cast Products, Rolled Products, and Energy. These assets include the largest bauxite mining portfolio in the world (with 45.3 million bone dry metric tons of production a year); a low cost, globally diverse alumina refining system; and an aluminum smelting portfolio.