Brazil offshore potash: South Atlantic Potash project lens for mine designers
Reviewed by Tom Sullivan

First reported on MINING.com
30 Second Briefing
South Atlantic Potash is advancing what could be the world’s first offshore potash mine in Brazil’s Sergipe-Alagoas basin, targeting a 27.5 m sylvinite layer at about 2.5 km depth with potential exceeding 3 billion tonnes and planned output of 2 million tonnes per year. The project will use solution mining via offshore wells, producing potash and saleable sodium chloride byproduct while avoiding tailings dams and solid waste storage. Leveraging data from more than 200 historical oil and gas wells, SAP has defined nine offshore targets across 189,000 ha but still needs resource confirmation, full engineering, permits and financing.
Technical Brief
- Solution mining will inject water via offshore wells, dissolve sylvinite, and pump mineralised brine topside.
- Crystallisation and refining plants onshore will separate potash from brine and recover saleable sodium chloride.
- SAP states no process chemicals are used; process relies on water-only dissolution and physical separation.
- Residual brine is slated for “rigorous environmental control”, implying discharge quality monitoring and permitting offshore.
- Over 200 legacy oil and gas wells plus seismic lines in Sergipe-Alagoas underpin potash target definition.
- Nine offshore exploration targets have been delineated in the Baixo Mosqueiro area off Sergipe’s coast.
- SAP has held and explored 189,000 ha since 2010, using petroleum datasets to vector potash drilling.
- Economic projections from SAP indicate US$600–800 million annual gains at nameplate output, contingent on approvals.
Our Take
Potash in Brazil has mostly appeared in our coverage as a strategic vulnerability within fertiliser supply; a Sergipe-Alagoas basin resource on the order of several billion tonnes would materially shift Brazil’s position from near-total import dependence towards partial regional self-sufficiency in Latin America.
The same oil and gas dataset underpinning this South Atlantic Potash work aligns with Brazil’s post‑2027 critical minerals policy emphasis on state oversight of oil, gas and potash noted in the Lula re‑election piece (26 Oct 2026), suggesting any Baixo Mosqueiro development will likely face tighter federal scrutiny on resource governance and royalties.
Using more than 200 legacy oil and gas wells to define nine potash targets in Baixo Mosqueiro is a textbook example of brownfield data mining; operators in other Brazilian sedimentary basins with hydrocarbon histories may look to replicate this approach for sylvinite, salt or brine‑hosted critical minerals with relatively low upfront exploration drilling costs.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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