SHIZUOKA, Japan, Jan 12 (Reuters): A Japanese mining ship departed on Monday for a remote coral atoll to probe mud rich in rare earths, part of Tokyo's drive to curb its reliance on China for critical minerals as Beijing tightens supply.

The month-long mission of the test vessel Chikyu near Minamitori Island some 1,900 km (1,200 miles) southeast of Tokyo, will mark the world's first attempt to continuously lift rare-earth seabed sludge from 6 km (4 miles) deep onto a ship.

Japan, like its Western allies, has been reducing its dependence on China for the minerals vital to the production of cars, smartphones and military equipment, an effort that has taken on urgency amid a major diplomatic dispute with Beijing.

"After seven years of steady preparation, we can finally begin the confirmation tests. It's deeply moving," Shoichi Ishii, the head of the government-backed project told Reuters, as the vessel departed the port city of Shizuoka on a bright sunny day, with a snow-capped Mount Fuji in the background.

"If this project succeeds, it will be of great significance in diversifying Japan's rare earth resource procurement," he said, adding that recovering the key minerals from 6 km below sea level would be a major technological achievement.

The vessel, with 130 crew and researchers, is scheduled to return to the port on February 14.

Photo from Reuters