Model mining units of the 20 th century and the economies ( production requirements , area requirements and vertical integration )

Manganese nodules on deep ocean floor have received attention as future resources for Co, Ni, Cu, and Mn these 40 years. The mining and metallurgical processing technologies studied these 40 years have been reviewed and re-examined on the basis of current interests, technologies, and economies by the author. The preliminary results of economic evaluation at the three timings, such as the last 1990s, 2004, and 2006, are introduced. Comparing with the nodule mining venture, advantages and disadvantages of cobalt-rich manganese crust and the Kuroko-type seafloor massive sulfide ones are also introduced.