Scientists find ‘easy’ way to extract rare earths from seafloor
While economists and geologists worry the world’s supply of rare earth metals will soon be outpaced by demand, a team of German geochemists has found a way to easily extract them from the vast deposits lying under the sea.
In a study, published last week in the journal Applied Geochemistry, the scientists suggest rare earth metals could be mined from the solid nodes of iron and manganese found strewn across much of the deep ocean floor.
These nodules, called ferromanganese deposits, build slowly over time as dissolved iron and manganese in seawater attaches to seafloor sediments.
Using the solvent desferrioxamine-B — a key ingredient of the method they have developed—these elements could be easily extracted.
The diluter binds more strongly to some metals than others and when applied to ferromanganese nodes, effectively and efficiently extracts rare earth metals, leaving other metals behind in the nodules.
The experts claim they were able to extract up to 80% of four rare earth metals from ferromanganese nodules by refining their ore-leaching method.
The finding, experts believe, may push miners to try securing a licence to explore the seabed for these materials, needed for portable electronics and hybrid vehicles batteries.
Since 2001 the United Nations’ International Seabed Authority has issued 30 exploration permits for the Pacific, Mid-Atlantic and Indian Oceans. But the body says there has been a rush of late, with at least another seven ready to be issued.
Last year, the UN published an update to its plan for developing a regulatory framework for deep sea mining, saying private firms would be allowed to apply for mineral, oil and gas extraction licenses as soon as 2016.
While rare earths metals aren’t as rare as their name lets on, they are hard to come by because they are widely dispersed amidst the Earth’s crust and seldom found in large deposits the way other minerals are.
Image by Stefano Garau.