It is the first time metals have been mined from the seabed in such quantities using ship-based extraction technology, according to the Economy, Trade and Industry Ministry and Japan Oil, Gas and Metals National Corp.
The effort was undertaken after a series of recent discoveries of ore deposits off the coast of Okinawa, according to the ministry.
From mid-August through late this month, JOGMEC deployed excavators to access the ore deposit at a depth of about 1,600 meters, sucking mineral ore up to the sea surface.
The ministry believes the mined deposit includes an amount of zinc equivalent to Japan’s annual consumption. The ore deposit also includes gold, copper and lead.
Six ore deposits have been found in the past three years in waters around the southwestern island prefecture of Okinawa, all within Japan’s exclusive economic zone.
The ministry expects more ore deposits to be found in the area and is planning to commercialize mining at those sites around the middle of 2020 following an economic evaluation scheduled to be conducted in fiscal 2018, from next April.
Japan relies heavily on mineral imports. After establishing a highly efficient means of extraction, the country “could possibly become a resource-producing nation if abundant quantities of deposits were confirmed,” the ministry said.
The deposits, known as hydrothermal minerals, are formed when material-laden water leaches out of rock in the Earth’s crust before being heated by magma and expelled out of the sea floor.