On-board measurement methodology for the liquid-solid slurry production of deep-seabed mining

The mineral resources in deep-seabed are attracting extensive attention because terrestrial natural resources have become progressively depleted. To optimize the mining system for the deep-seabed minerals, the production rate and the solid fraction of liquid-solid slurry production should be estimated and measured, precisely. However, there are very unstable on-board conditions due to the wave, tide, etc. In this research, we studied on on-board measurement methodology to estimate the production rate and the solid fraction of the deep-seabed mining. We proposed a measurement technique using the measured data and physical properties of materials. The technique has been verified by the real sea experiment using pilot-scale lifting system. Also we performed the Fast Fourier Transform (FFT) analysis because there are significant noises in the measured data. As a result of the FFT analysis, we found that the causes of the noises were due to the vessel behavior by the wave energy and the sloshing effect of the slurry in the storage tank.