Brazil Potash Corp, a mineral exploration and development company advancing the Autazes potash project in Amazonas State, Brazil, has announced the award of a second Front-End Engineering Design (FEED) contract for mine shafts and underground development to WSP UK Ltd, with Redpath Deilmann as subconsultants for the mine shafts scope.
WSP UK Ltd. and Redpath were selected for their extensive global experience in potash shaft sinking, proven capability under complex geotechnical conditions, and Brazilian regulatory alignment through a standalone agreement with WSP Brasil, it said.
The 2022 prefeasibility study on Autazes stated that the mine would be accessed by means of two vertical shafts: main shaft (#1) and ventilation shaft (#2) and related infrastructure. The shafts, in this study, were designed to service a mine production rate of 8.5 Mt/y at steady state.
Raphael Bloise, Project Director of Brazil Potash, explained: “Awarding this second FEED to WSP and Redpath means every component of the Autazes project, both underground and surface, now has world-class engineering teams behind it. Redpath is among the most experienced teams globally in potash shaft sinking, and bringing them to Autazes gives our lenders and partners the engineering rigor they need to move forward. We are one step closer to the day Brazil stops importing 95% of its own fertiliser.”
With the Surface Facilities and Infrastructure FEED already awarded to Wood and Promon Engenharia, this award closes the loop on engineering design across the full Autazes scope. Mine shafts and underground development will now be developed to the same level of engineering fidelity as the surface works, creating a unified, lender-ready engineering basis for the entire project, according to Brazil Potash. The completion of FEED studies is a critical milestone for securing construction debt financing, which is currently being advanced through ongoing dialogue with Development Finance Institutions and Export Credit Agencies. The FEED phase converts conceptual and prefeasibility premises into detailed engineering documentation intended to support lender due diligence, establishing the foundations required for bankability, investment readiness, and long-lead procurement.
Redpath has participated in and delivered shaft sinking works on more than 500 shafts worldwide, including numerous historic shafts in the Saskatchewan potash basin in Canada, as well as major recent potash projects such as Jansen, Woodsmith, Rocanville, K3 and Nezhinsky, employing ground freezing and grouting techniques together with both mechanised and conventional shaft sinking methods, some of which have been completed and others are currently under execution.
Shaft sinking constitutes the critical path for the Autazes project, with the two shafts defining the entire construction schedule. All subsequent infrastructure, including the processing plant, tailings, logistics and underground development, depends on the timely and safe completion of the shafts.
While Redpath leads shaft sinking and constructability, WSP UK Ltd contributes the engineering backbone of the FEED — covering geo-mechanical analysis, freeze modelling, shaft liner design and structural assessments. WSP Brasil supports compliance with Brazilian regulatory frameworks, integrating local execution with global engineering standards. Together, this integrated team is designed to provide lenders with confidence that the FEED meets both international best practice and Brazilian regulatory requirements, Brazil Potash says.
The estimated total value of the FEED contract, subject to authorization of subsequent phases, is $26 million. At this time only the first phase, early works has been awarded and spans 12 months with a value of $4.3 million and encompasses geotechnical investigation, freeze modelling, basis of design development, and the regulatory and engineering foundations required to advance to full FEED execution.
The main shaft, as envisaged in the 2022 study, will serve as the down cast ventilation conduit with a finished diameter of 7.8 m and a depth of 920 m. The ventilation shaft will serve as the up cast exhaust ventilation conduit and a second means of egress with a finished diameter of 6.9 m and a depth of 868 m. The study report added: “Shaft sinking will be completed by means of conventional drilling and blasting with mechanical mineral loading into the kibbles. The main and ventilation shafts will be sunk concurrently and equipped from the bottom up. Permanent headgears will be erected for the shaft sinking and two double drum winders will be installed and used as kibble winders in both shafts. On completion of shaft sinking the ventilation shaft double drum kibble winder will be decommissioned and moved to the main shaft for permanent installation and commissioning as the second mineral winder.
“Shaft sinking, equipping and commissioning will take approximately 3.5 years. Ground stabilisation will be required for incompetent ground for the first 420 m below surface and will be completed by means of freezing and grouting. Grouting will continue until the shaft sinking and lining are complete.”
With an initial planned annual potash production of up to 2.4 Mt/y, Brazil Potash’s management believes it could potentially supply approximately 20% of the current potash demand in Brazil. Management anticipates 100% of Brazil Potash’s production will be sold domestically to reduce Brazil’s reliance on potash imports while concurrently targeting a reduction of an estimated 1.4 Mt/y of GHG emissions.