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 1,900km (1,200 miles) southeast of Tokyo, will mark the world’s first attempt to continuously lift rare earth seabed sludge from 6km deep onto a ship.Japan, like its Western allies, has been reducing its dependence on...