Current status and problems of exploration and development of world ocean metal mineral resources

The world seabed holds abundant metal mineral resources. The minerals on the seafloor such as cobalt, nickel, rare earth, and other minerals, are tens or even hundreds of times higher than those on land. Therefore, they are considered the ideally alternatives for future mineral explorations. This paper introduces the current status, distribution and potential of these resources in the world’s ocean, including polymetallic nodules, Cobalt-rich crusts, polymetallic sulfides and deep-sea REEs. This review analyzes and summarizes the cases of metal mineral exploration contracts in the international subsea area since the 21st century, and discusses the advances in the mining tests of polymetallic nodules and polymetallic sulfides in the Exclusive Economic Zones of Russia, Papua New Guinea, Japan, China and other countries. Considering that the world's ocean metal mineral resources are abundant and have great potential, their exploration and mining are increasingly emphasized by governments all around the world. International seabed exploration contracts have been continuously increased, and commercial exploitation has been put on the agenda, but the mining of metal mineral resources in the international seabed areas still faces many constraints and challenges in terms of technology, regulations and environmental protection.