Deep-sea polymetallic nodules are considered as an important potential resource for Nickel, Copper, Manganese and Cobalt. The research has showed that they contain alarge variety of other metals, including molybdenum, zinc, zirconium, lithium, platinum, titanium, germanium, yttrium, and REEs, which increased the nodules combined value as an alternative supplies for expanding economies, high technology and emerging green energy technologies.
The highest nodule abundance (more than 10 kg/m2) with the high average percentage of metals (at least 2.5 % content for Ni+Cu, 0.2% Co, 30% Mn, 0.15% Zn,0.07% Mo, etc.) were found at seafloor in the eastern equatorial Pacific (Clarion-Clipperton Fracture Zone, CCZ) and in the central equatorial Indian Ocean.
Within the recent decade, the International Seabed Authority (ISA) granted several national and multinational entities exclusive 15-years contracts for polymetallic nodules exploration in the claim areas, each covering75000 km2 in the international seabed area. The commercial viability of nodule mining has yet to be established, but the size of deposits, the grade of several metals contained in nodules as well as the promising trends in metal market continue to motivate contractors to carry out their exploration activity.