Economic Feasibility Analyses for Seafloor Massive Sulfide Mining in Okinawa Trough Area, Japan

The best model of the SMS exploitation in Japan is examined in this study by applying economic feasibility analyses under many assumptions. The distribution model is assumed like the most explored SMS ore body in Okinawa Trough Area. An ore separation on the seafloor by physical process is included in both the production models examined in this study. The ore separation ratio is assumed as 50%. Two ore lifting methods are compared in the production models. One is a hydraulic lifting by loop self-standing risers and the other a mechanical lifting by polyethylene rope and mesh-bags. The capital expenditure and operating expenditure of mining, transportation, and mineral processing are calculated on the basis of the reports obtained from an SMS mining venture in Papua New Guinea. Some reasonable operation conditions in Okinawa Trough Area and average metal prices of current ten years are applied. The results show no economy under the current models and assumptions. However, some points of technological challenge to improve the economy become remarkable.