Ideal mixing proportions of carrier materials used for lifting ores for deep sea mining by sphere falling tests

To transport ores from seafloor to sea surface is one of the crucial problems for deep sea mining. As one of novel and promising solutions for this, the authors proposed a carrier material circulation method. For this method, as the appropriate viscosity of the carrier materials are important for efficient transportation of the ores, the purpose of this research is to suggest the ideal mixing proportions of carrier materials. Thus, to evaluate viscosity of carrier materials and the terminal velocities, viscometer measurements and sphere falling tests were carried out. Then, by assuming the carrier materials as Bingham fluids, the ideal mixing proportions was suggested for ores of various diameters and densities.