Development of Potential Examination Method for Cobalt-Rich Manganese Crusts

摘要

Cobalt-rich manganese crusts on seamounts and manganese nodules on deep ocean floor have both been received attention as future resources for Co, Ni, Cu, and Mn. Lack of information on cobalt-rich manganese crusts has precluded comparisons between the two sources in terms of their technical and economical advantages. In the past 15 years, Japan has surveyed the cobalt-rich manganese crusts; therefore, it seems the proper time to compare the two. In this paper, we consider distribution features and R&D results to develop a method for examining and comparing the economical potentials of manganese nodule and cobalt-rich manganese crust mining. Through the preliminary evaluation of the two, the effectiveness of the method is confirmed. Cobalt-rich manganese crust development seems a risky but high return venture because of its high sensitivity to cobalt prices. Manganese nodule development, on the other hand, is considered to be a stable and good for a long-term venture. One of the application fields will be the selection of suitable metallurgical processing. A lower substrate ratio in excavated ore is clearly required for the economy of the crust development. In order to improve the evaluation, detailed technical information for the recovery efficiencies in the subsystems and units is necessary.