Experimental study on seabed disturbance induced of the rotary rake-based deep-sea polymetallic nodule mining device

This is the authors' abstract. We don't add key points for this paper.

Global interest in commercial deep-sea polymetallic nodule mining is increasing, driven by EV demand, national defense, and grid upgrades for the energy transition. Accordingly, sediment disturbance induced by rotary rake-based collector is evaluated to address high disturbance, low efficiency, and structural complexity. Specifically, a full-factorial experiment is conducted with 3 factors: rake-tooth rotational speed, driving speed, and nodule size. The effects of key parameters on sediment disturbance are characterized. Furthermore, a model for disturbance magnitude is derived. Finally, quantitative relationships are established between disturbed sediment volume, the collector’s structural parameters, and sediment-particle kinematics. The results show that the mathematical models are within 20% error range of the test result data, which proves that the models have relatively good fitting accuracy and predictive ability. The collection rates of the 9 working conditions are basically above 90%, and the disturbance depth is all less than 3 cm. Meanwhile, the amount of disturbed sediment in the optimal working condition is at least 4 times less than the traditional hydraulic type. This study provides theoretical basis and experimental support for high efficiency and low disturbance acquisition of polymetallic nodules, and provides environmental disturbance data reference for subsequent equipment optimization design and engineering amplification application.