Sedex Desalination, a subsidiary of mineral exploration and development company Frontier Rare Earths, has commissioned consulting and engineering services provider Royal HaskoningDHV to undertake a feasibility study to establish the viability of implementing a seawater desalination scheme at the Zandkopsdrift rare earths project, in Abraham Villiers Bay, in the Northern Cape.

The proposed plant would have a 7 Mℓ/d capacity and would supply potable and process water to the Zandkopsdrift mine, which was currently in the development phase.

The feasibility study would be carried out from March to December at an undisclosed amount. It is aimed at determining the configuration, size, phasing and lowest possible life-cycle cost of the project, while assuming its development had the least impact on the physical and social environments surrounding the proposed scheme as possible.

Key aspects of the project included marine works, which would comprise the sea intake and outfall works; a desalination plant; bulk water-supply infrastructure; bulk power-supply infrastructure; road access to the desalination plant; a transfer pipeline; and power lines.

“The study envisions that potable water will be withdrawn from a 20 Mℓ capacity storage reservoir at the seawater desalination plant and pumped via a rising main to a height of about 191 m above sea level, over a distance of about 6.84 km,” Royal HaskoningDHV project manager Jack McGhie said in a statement.

He explained that the potable water would gravitate further over a distance of about 10.66 km to the district of Kotzesrus, at a height of about 167 m above sea level. From Kotzesrus, the water would be pumped further through a booster pumpstation and through a rising main to a height of about 223 m above sea level, over a distance of about 2.3 km.

The potable water would then gravitate for the last portion of the pipeline, over a distance of about 12.8 km to the Zandkopsdrift mine raw-water storage reservoir, at a height of about 203 m above sea level.

Royal HaskoningDHV has constructed most of South Africa’s desalination and effluent reuse plants, including installations at Plettenberg Bay, Knysna, Sedgefield and Mossel Bay.