To cope with anticipated demand increase in metals and associated supply risk in the future, DORD is working on resource development of polymetallic nodules, which are highly promising as a future supply source. We are aiming for sustainable, efficient, and economical resource development while taking into consideration the global environment, including marine environment.
DORD is considering to adopt a self-propelled ore collector system with a structure that moves while pulling a flexible riser (FR), which enables accurate route control. Although it has not been conducted in the marine environment, a paddle wheel type is currently under consideration as a collection method. By tentatively setting the internal diameter of the FR at 200 mm, the pump capacity and lifted quantity was calculated and the results of lifted quantity was approximately 3,300 t(wet)/day per one set of collector. From this results, it is assumed that three sets of mining system will be required to reach an annual lifting quantity of three million t(wet)/year.
DORD has been working on development and verification of technologies to safely and efficiently extract base metals and rare metals such as copper, nickel, and cobalt contained in polymetallic nodules, as well as examination of selectable options.
From the viewpoint of the economic viability that is most important for commercial development of deep-sea mineral resources, DORD has been working on economic evaluations, focusing on the processing cost which accounts for about 70% of the development costs of polymetallic nodules, including uncertainties such as everyday metal price fluctuations.