Forget scouring the sea floor for shipwrecks. Nautilus Minerals is after more abundant oceanic treasure - and it has three mammoth machines to help.
"Mineral deposits found on the sea floor - copper, nickel, cobalt, gold and zinc - tend to be present in much higher grades than on land," explains Mike Johnston, CEO of the Toronto-based deep-sea mining company. Extracting them requires diving down into a high-pressure, pitch black, often volcanic environment, but for Johnston, the prize is worth the risk.
"The average grade of copper ore mined in an open pit is about 0.6 per cent," he says, "but on the sea floor we've found about eight per cent." Higher-grade ores mean less rock needs to be dug up, thus reducing toxic waste from extracting metals from the ore, which is typically stored in enormous dams called tailings. "These do fail, and it tends to happen around every five years," says Johnston. "With our project the ore is so high grade everything can be extracted without producing any tailings at all."
Undersea minerals appear in two forms: as sulphide deposits where gaps between tectonic plates vent hot metals into the ocean, as at Nautilus's Papua New Guinea site, Solwara 1; and as fields of potato-sized nodules laying deep in the middle of oceans, formed by the precipitation of metals from seawater over millions of years. "The area of the central Pacific covered by these minerals is approximately the same size as the United States," says Johnston. "There's enough copper already known here to provide for our next 30 years of consumption worldwide."
Solwara 1 is first on the agenda. Nautilus has secured mining rights to the 1,600-metre-deep site and took delivery of its first three mining machines in February 2016. Mining of the site's estimated one million tonnes of mineral ore is intended to begin in 2018. "A lot of people will be watching the first one, to see how this will work," says Johnston. "We can show them models and consultant reports, but there's nothing like actually doing it."
This article was originally published by WIRED UK
