Indonesia's bauxite reserves stand at 2.77bn tonnes as downstream expansion gathers pace

Indonesia holds approximately 2.77 billion wet metric tonnes (Wmt) of bauxite reserves across four key regions, with West Kalimantan accounting for the largest share of the country's reported deposits. The figures highlight the importance of the province to Indonesia's growing aluminium ambitions as the country shifts towards domestic alumina refining and primary aluminium production.

Indonesia's total bauxite resources amount to approximately 7.28 billion Wmt. West Kalimantan dominates this resource base, with 5.52 billion Wmt, alongside reserves of 2.31 billion Wmt. This makes the province the country's principal bauxite-bearing region.

Riau Islands represents the second-largest resource base, with approximately 1.36 billion Wmt of bauxite resources and 319.35 million Wmt of reserves. Central Kalimantan holds 401.82 million Wmt of resources and 144.14 million Wmt of reserves, while Bangka Belitung Islands accounts for a further 3.10 million Wmt of resources.

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West Kalimantan leads Indonesia's bauxite reserve base

The regional distribution shows how heavily Indonesia's bauxite reserves are concentrated in West Kalimantan. Its 2.31 billion Wmt of reserves account for more than four-fifths of the combined reserves represented in the regional dataset.

This resource concentration is particularly significant as Indonesia accelerates investment in domestic alumina refineries and aluminium smelters. The government introduced a bauxite export ban in June 2023 to encourage domestic processing and move the country's mining industry further up the value chain.

The policy has supported plans to expand smelter-grade alumina production capacity from 7 million tonnes per year in 2025 to a projected 32.5 million tonnes by 2030, according to the Centre for Research on Energy and Clean Air (CREA). Over the same period, annual bauxite demand is expected to increase from approximately 14 million tonnes to 65 million tonnes.

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Rising demand puts resource management in focus

The expansion of Indonesia's downstream aluminium industry is expected to place greater pressure on domestic bauxite supplies. CREA has warned that the country's proven bauxite reserves of approximately 1 billion tonnes could be depleted in less than 12 years under the planned expansion trajectory.

The concern comes as Indonesia seeks to establish itself as a major alumina refining and aluminium production centre outside China. However, the pace of downstream investment will need to be balanced against the availability of raw materials and the long-term sustainability of mining operations.

With West Kalimantan holding the largest share of the country's reported bauxite reserves, the region is likely to remain central to Indonesia's efforts to strengthen its domestic aluminium supply chain.

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