Bauxite was being mined in the early 1990s by P.T. Aneka Tambang on Bintan Island and three neighboring islands, and most bauxite was exported to Japan. Total bauxite reserves of 396 million tons were found in the Bintan Island area and in Kalimantan Barat Province. Reserves of commercially exportable bauxite were much more limited, although on-site processing into alumina had the potential to be commercially feasible with below export grade reserves. Bauxite, the demand for which had increased during Repelita V after having slowed down during Repelita IV, is a primary input in the production of aluminum. It must first be refined into alumina. Plans were underway in 1991 for an alumina refinery, and the Department of Mining and Energy had been seeking an interested foreign partner to develop a US$600 million facility on Bintan Island since the late 1980s. Alumina input for P.T. Indonesia Asahan Aluminum was imported from Australia.
Data as of November 1992