Already planning to mine phosphate deposits on the Chatham Rise, Chatham Rock Phosphate has also identified lucrative rare earth minerals on the Chatham Rise seafloor, and is studying a commercial procedure for separating them from the sand in which they are embedded. By PETER OWENS.
ON CURRENT MARKET values, the rare earth minerals would dwarf the multimillion-dollar value of the initial Chatham Rise target of phosphate nodules trapped in the seafloor sand. Rare earth mineral prices have soared in recent months as 97 percent global supplier China has delivered less to the world.
Chatham Rock Phosphate’s plans are to suction up and separate out phosphate nodules from the seafloor at depths of up to 450 metres, taking up to 1.5 million tonnes a year, but during seafloor sampling several years ago it identified, quantified and valued the rare earth minerals present, says Chatham president and CEO Chris Castle.
Castle says the mining operation would be carried out by a modified 235-metre-long dredge, and says the company has been aware of the rare earth minerals for some time as they have been coming up with the nodules. The present work is aimed at learning how to separate them from the slurry as it crosses the ship.
“Nodules are easy to separate; minute particles of rare earths less so,” Castle says. He also revealed that sampling was carried out by a variety of methods using remotely operated underwater vehicles, grabs, box corers and penetrometers.
In some industries, the 17 rare earth minerals are considered to be the new ‘green mineral’ future of the renewable energy sector, with uses in solar energy applications, catalytic converters, lighting, magnets and the development of massive-capacity batteries for e-cars and houses.
“The value of these rare earths dwarfs the value of the phosphate, even though rock phosphate annual revenues are projected at $270 million,” says Castle. “A recovery of only one percent of the rare earths would be very significant.”
He added the company was about to commission a research project with an unnamed “local” university, expected to be the University of Otago.
“Research will be aimed at separating valuable by-products, including rare earths that are also contained within the sandy seafloor matrix that contains the rock phosphate deposit.”
As Chatham’s proposed phosphate recovery process would already bring seafloor sands to the surface vessel there would be no mining cost involved, just the cost of separating the rare earth by-products from the sand, which was yet to be worked out.
“Successful recovery of even a tiny proportion of these by-products could add significantly to our future revenue and profitability prospects and also establish a strategic ocean-floor-based asset for New Zealand.”
However, in a statement to the New Zealand Stock Exchange Castle warns there is no certainty that any of these rare earths can be recovered.
Recently Chatham Rock Phosphate launched a $1.24 million capital-raising programme as it prepares for a second application to gain a marine consent from the Environmental Protection Authority (EPA) for its Chatham Rise phosphate project.
Its previous attempt, after it spent about $33 million on research and development, was turned down by the EPA in February 2015.