West Kalimantan holds most of Indonesia’s bauxite ore reserves, positioning the province at the center of the country’s mineral-processing push. As bauxite overtook nickel in second-quarter downstream investment, new and existing alumina projects could strengthen Indonesia’s domestic aluminum supply chain. Moreover, these projects could reduce imports and create higher-value industrial activity nationwide over time.

PONTIANAK, thekabarnews.com—West Kalimantan is emerging as the center of Indonesia’s bauxite downstream industry. This shift followed the commodity overtaking nickel as the country’s largest recipient of mineral-processing investment in the second quarter of 2026.

Investment and Downstream Minister Rosan Perkasa Roeslani attributed the shift to processing projects developed by Indonesian and foreign investors.

“Bauxite is number one. Usually, as we know, nickel has always led. There is a shift toward bauxite because several bauxite projects are being developed by domestic and foreign investors,” Rosan said during a government investment briefing in Jakarta on Thursday, July 16.

Bauxite downstream investment reached Rp40.1 trillion between April and June, making it the leading mineral commodity for the quarter.

Overall downstream investment totaled Rp152.7 trillion, up 5.7 percent from the same period in 2025. This is equivalent to 29.8 percent of Indonesia’s total second-quarter investment of Rp511.8 trillion.

Indonesia attracted Rp511.8 trillion in investment during the quarter, representing annual growth of 7.1 percent. The investments created jobs for more than 742,000 Indonesian workers, according to the Investment Ministry’s official report.

The latest Energy and Mineral Resources (ESDM) Ministry report was published in 2025 using data updated through December 2024. This report records approximately 2.39 billion tonnes of crude bauxite ore reserves across 123 locations in West Kalimantan. That represents about 83.5 percent of Indonesia’s recorded total of 2.87 billion tonnes.

The ESDM ministry report also estimates that West Kalimantan holds about 459.6 million tonnes of alumina content within those reserves. This figure differs from the frequently cited estimate of 840 million tonnes, or 66.77 percent of national reserves. That estimate came from an older dataset.

Globally, the 2026 US Geological Survey (USGS) report places Indonesia fourth in bauxite reserves, with an estimated 2.9 billion dry tonnes. Only Guinea, Australia and Vietnam hold larger reserves. The USGS estimates total global reserves at about 29 billion tonnes.

West Kalimantan already hosts key parts of Indonesia’s aluminum supply chain. The smelter-grade alumina refinery in Mempawah has a designed capacity of one million tonnes of alumina annually. It processes locally mined bauxite for Indonesia’s aluminum industry.

The government also launched additional alumina and aluminum projects in Mempawah on February 6, 2026. The projects aim to convert bauxite into smelter-grade alumina and process alumina into aluminum, according to the ESDM Ministry.

Together with Antam’s chemical-grade alumina facility in Tayan, these investments could help West Kalimantan become Indonesia’s main alumina production hub.

Achieving that goal will require reliable electricity, port and road infrastructure, responsible mining practices and strict management of refinery waste.