An Integral Design Approach for Deep Sea Mining Systems Using Dredging Technology

Experience in the area of wet mining and the dredging industry learns that the excavation system cannot be seen separate from the slurry transportation system. These two key systems in a deep sea mining operation interrelate to such extend that they must be developed towards an integral solution. The nominal production, peak production and variability of these figures must match for all sub-systems in the overall mining system to optimize for mining efficiency; we call this the ‘game of capacities’. Also the configuration of the excavation and transport system has great consequences. For instance an important question is whether to place the first pump and its drive of the slurry transport system on the seafloor mining tool or in the riser system. The choices made impact amongst others on; the mining tool’s reach (and thus efficiency), the seafloor mining tool’s propulsion system and its geo-mechanical interaction, the slurry transport flow and pumping power requirements. This paper will discuss the several dependencies of the (producing) subsystems and important choices for configuration and their consequences regarding technology, capex, opex, reliability and maintainability.