Numerical simulations and large-scale experimental research into air-lifting system for deep-sea mining

The deep seabed harbors abundant mineral resources. To achieve the economic viability of deep-sea mining, the efficiency of polymetallic nodule lifting is critical. In this study, we investigate the performance of air-lifting systems, which is a key component of deep-sea mining operations. Through two-phase flow simulations, we establish the relationship between the air-injection velocity and water-lifting velocity and validate the experimental data. We constructed a large-scale air-lifting system in a 20-m-deep water tank to explore the feasibility and energy efficiency of lifting water and nodules under varying air-injection velocities and depths. In detailed energy efficiency calculations, we determined the optimal operational parameters which provide novel insights into the design and optimization of deep-sea mining lifting systems. The experimental data and findings offer valuable references for future system designs that can enhance operational stability and economic feasibility.