Innovative tailings management for marine ferromanganese nodule and crust processing

Three factors have significantly increased the likelihood that manganese nodule and crust resources will be mined in the near future. These are (i) the legal clarification provided by the Law of the Sea Treaty now in full effect, (ii) the rapid economic growth in East Asia and (iii) the sharp rise in world cobalt prices. The Chinese Ocean Mining Company has announced plans to begin mining and is looking at joint venture possibilities with American companies. One of the major concerns with marine mining development is environmental. Current studies show 80% of the environmental effect to be associated with ore processing, particularly tailings disposal. New work indicates that tailings from proposed hydrometallurgical processing can be made into useful construction products. These include tiles, ceramics, coatings, resin castings for plumbing fixtures, additives to strengthen concrete, stack gas cleaners, rust-proofing and antibiofouling coverings. The economics of such a venture look favorable to the point that costs of tailings disposal should be zero or cash-generating on the basis of revenues from tailings products. This approach is an innovative strategy for tailings management and reduces potential environmental damage associated with marine mining.