Filtered seawater has been identified as a reliable, unlimited and economic option for use in the sulphate of potash (SoP) production process at ASX- and LSE-listed Danakali’s Colluli potash project, in Eritrea.

The company reports that extensive test work has confirmed the economic, operational and environmental benefits of redesigning the water intake treatment area (Wita) at Colluli to use filtered seawater.

The company explains that previously it would have needed to build a large seawater desalination plant and a pipeline to transport the water to the Colluli processing plant.

Test work conducted by the company and the Saskatchewan Research Council over the past six months has, however, made it possible for the company to instead consider building beach wells that will filter the seawater that will then be transported to the project area for use in the processing plant.

Danakali states that the proposed redesigned Wita has a materially smaller onshore and offshore footprint; requires less power, thereby reducing operational expenditure (opex), fuel costs and carbon dioxide emissions; and requires less capital expenditure (capex), while reducing sustaining capex over the life-of-mine (LoM).

"Using filtered seawater as an unlimited input in our production process is not only a world first, but also a long-term game changer.

“This will reduce capex, opex and sustaining capex over a very long time and have a massively positive environmental impact onshore and in the Red Sea for the 200-year LoM," comments executive chairperson Seamus Cornelius. 

While the previously considered desalination plant would have had a power requirement of about 1.3 MW, the redesigned Wita’s power requirement is much lower and Danakali is investigating the use of renewables and battery storage as an energy source.

“With the Wita redesign, our energy requirements are materially reduced, bringing us closer to our zero carbon goals. 

“I am extremely proud of our team in Canada who focused on developing and repeatedly testing the ore streams and other inputs to create the most operationally efficient and cost-effective SoP production method for Colluli, which allows us to produce the required high quality and quantity of SoP for our offtake partners," says Cornelius.