Alumar smelter (São Luís): an aluminum operation in Brazil
Alumar smelter (São Luís) is an aluminum smelter producing aluminum in São Luís, Brazil. The sources report 144 kt, 'Aluminium production' (saleable production), South32 share for FY2026 (1 July 2025 to 30 June 2026); the basis is South32's 40% share. Measured as primary aluminum, whole-operation output for FY2026 (1 July 2025 to 30 June 2026) is about 360,000 tonnes (derived here, not printed by the source): about 0.5% of world aluminum output in 2025 and about 30% of Brazil's; it is one of 28 operations on this site whose output can be stated in primary aluminum.
Who owns and operates it?
| Owner | Interest | As of |
|---|---|---|
| South32 | 40% | 20 July 2026 |
| Alcoa Corporation | — | 31 December 2025 |
How much does it produce?
| Period | Output | Basis | Where in the source |
|---|---|---|---|
| FY2026 (1 July 2025 to 30 June 2026) | 144 kt, 'Aluminium production' (saleable production), South32 share | South32's 40% share | Section 'BRAZIL ALUMINIUM (40% SHARE, NON-OPERATED)', 'Aluminium production (kt)' row, FY26 column; text 'saleable production increased by 4% (or 6kt) to 144kt in FY26' · South32 Limited |
| FY2025 (1 July 2024 to 30 June 2025) | 138 kt, 'Aluminium production' (saleable production), South32 share | South32's 40% share | Section 'BRAZIL ALUMINIUM (40% SHARE, NON-OPERATED)', 'Aluminium production (kt)' row, FY25 column · South32 Limited |
Between FY2025 (1 July 2024 to 30 June 2025) and FY2026 (1 July 2025 to 30 June 2026) the reported figure rose by 4.3%, in the same unit and on the same basis.
How the primary-aluminum figure is worked out. South32 prints 144 kt for its 40% share of saleable production at Brazil Aluminium in FY2026. 144 / 0.40 = 360 kt, which is 360,000 tonnes for the whole smelter. World smelter production of primary aluminum in 2025 was 74,000,000 tonnes (USGS Mineral Commodity Summaries 2026); Brazil produced 1,200,000 tonnes.
The period (FY2026 (1 July 2025 to 30 June 2026)) is not the calendar year of the USGS totals (2025), so the shares are approximate.
Status: ramping, as of 20 July 2026.
- South32 prints no whole-smelter tonnage; the figure is derived from its 40% share. Alcoa's 10-K prints capacity for the smelter but no production by smelter.
- South32's announcement of 1 July 2026 lists its 40% interest in the Brazil Aluminium smelter among the assets it agreed to sell to Alcoa; shareholders approved the sale on 15 October 2026 per its September 2026 quarterly report.
How does it compare?
Other aluminum operations on this site: Alma smelter, Alouette smelter, Bécancour smelter, Boyne Island smelter, Tomago smelter, Kitimat smelter, Tiwai Point smelter, Sohar smelter, Laterrière smelter, Grande-Baie smelter, ISAL smelter, Bell Bay smelter. In Brazil: Albras smelter. See where aluminum comes from for the country totals, the country page for Brazil.
Sources
- South32 Limited: Quarterly Report: June 2026 (quarterly report (stock-exchange announcement, 2026-07-20; text read in the Investegate copy of the RNS), Q4 FY2026 and FY2026 (to 30 June 2026)). Opened 4 November 2026; used: production summary table; sections for Hillside Aluminium, Mozal Aluminium and Brazil Aluminium.
- Alcoa Corporation: Form 10-K for the year ended 31 December 2025 (annual report (SEC 10-K, filed 2026-02-26), CY2025). Opened 4 November 2026; used: printed pp.4-5 (Aluminum segment, smelter capacity table).
- South32 Limited: Quarterly Report: June 2025 (quarterly report (stock-exchange announcement, 2025-07-21; text read in the Investegate copy of the RNS), Q4 FY2025 and FY2025 (to 30 June 2025)). Opened 4 November 2026; used: sections for Hillside Aluminium, Mozal Aluminium and Brazil Aluminium.
- U.S. Geological Survey: Mineral Commodity Summaries 2026: Aluminum (government statistical summary, 2025 (world and country smelter production)). Opened 3 November 2026; used: world smelter production and capacity table.
Method and limits
- Reported, not estimated. Output is the figure the operator or owner published, in the unit it used. This site does not estimate output where none is published.
- Shares. A share divides output in primary aluminum by the USGS world or country total for 2025. Where the operator's year is a fiscal year or the unit is a concentrate or a carbonate equivalent, the share is approximate or not given.
- What is compared. The figure is tonnes of primary aluminum metal produced by the whole smelter, compared with USGS smelter production of primary aluminum. Remelted and recycled metal is not primary production.
- Whole operation or owner's share. The basis column says which. A joint venture's output is never counted twice.
- Partial list. Only operations with a published figure are listed, so the rank is among those on this site, not among every aluminum mine. Shares of a country's output mix periods and bases, so treat them as indicative.
- Made with AI assistance, checked against sources. The facts were gathered from the documents above by AI-assisted research and re-checked against those documents by a second, independent pass; the page text is generated from the data. No professional review took place. How the site is made. To report an error, contact us; fixes are logged on the corrections page.