harnessing sun and wind to produce salt & SOP
The production of high-quality industrial salt is unique in that the sun and the wind do most of the work. The Mardie production process is based on solar evaporation and downstream crystallisation – centuries-old techniques, scaled up with modern infrastructure and precision engineering.
The Pilbara coast is the premier destination for solar salt operations, with five other projects successfully operating in the region for up to fifty years. With warm weather, low rainfall, low humidity, high windspeeds, and a large area of impermeable mud flats, Mardie has all the key characteristics of a world-class salt operation.
Producing high-quality salt is a long and patient process—taking approximately two years from seawater intake to final harvest—demonstrating a tried-and-tested method that consistently delivers high-value product.
How it Works
Seawater Intake
Seawater is drawn from the Indian Ocean through a dedicated seawater intake facility using state-of-the-art pumps.
Evaporation Ponds
A vast network of nine evaporation ponds is used to concentrate the brine over approximately 12 months. These ponds cover around 90% of the project area and rely entirely on natural solar and wind energy.
Crystallisation
Salt begins to crystallise once the brine reaches saturation. Primary and secondary crystallisers work in sequence to maximise recovery of sodium chloride. The crystallised salt is then harvested and transported for washing and refining.
Salt Wash Plant
The salt wash plant cleans the salt and removes any impurities. This is where the salt becomes industrial grade, ensuring consistency and high quality to meet market specifications.
Sulphate of Potash (SOP) Production
After salt is harvested, the residual brine is further processed to extract potassium salts, which are converted into SOP using a dedicated processing plant. BCI is finalising the design of an SOP pilot plant to ensure testing and trialling is conducted first.
Any leftover seawater will get recirculated back into our evaporation ponds. This reduces the amount of water we take out of the ocean and minimises our environmental footprint.
Export via Port of Cape Preston West
A 2.4-kilometre jetty at Cape Preston West will support a transhipment operation, enabling the loading of ocean-going vessels up to Newcastle Max size at the designated transhipment anchorages.
Why it matters
Mardie has been designed from day one as a long-life, multi-generational asset. It is fully funded for the salt-first phase and backed by NAIF, Export Finance Australia and global commercial lenders.
It is also a project of strategic national interest. Mardie will secure Australia’s position as a major supplier of high-purity industrial salt to the Asia-Pacific region, reduce reliance on international imports, and create long-term value for shareholders, regional communities and industry.
Mardie is well on its way to becoming one of the most important salt and potash operations in the world.
