Distribution Characteristics of Cobalt-Rich Manganese Deposits and Fundamental Considerations of the Mining Technology.

Importance of cobalt-rich manganese deposits on the Pacific seamounts for a future cobalt resource has currently been well recognized. Though the geological information has been well recognized, no sufficient quantitative data of the deposits is available to aid design of the mining system.Requirements of the quantitative data for the resource assessment are summarized.Methods for clarifying microtopographic distribution characteristics of the deposits and relationship between the microtopography and morphology are introduced. Large-diameter gravity corer and the results, such as the shallow-buried deposits and the multiple layering are summarized.Degradation of mined crusts by their substrate is simulated. Resource potential considering the shallowburied deposits is examined.Geotechnical characteristics of crusts, substrates, nodule, and sediments are studied. On the basis of the results, requirements for design of the mining system are discussed and the mining system and seafloor miner are overlooked. Future studies for the further understanding of the deposits are presented.