Effects of confining pressure and cutting sequence on the cobalt-rich crust cutting mechanism by using conical picks in ocean environments

Abstract

Confining pressure and cutting sequence of conical picks directly affect the ocean mining efficiency. The simulation model of cobalt-rich crust cutting with two-dimensional discrete element method is established to simulate the whole process of crack growth. According to the obtained crack growth patterns and the rules of fracture-block formation, four typical fracture modes are summarized, and the fracture mechanism is further studied from three aspects: the efficiency of cobalt-rich crust cutting, the ability of crack growth and the size of fracture-block. The results show that with the increase of confining pressure, the cutting efficiency and crack growth ability decrease, and the cutting efficiency of simultaneous loading is larger than that of the sequential loading, while the crack growth ability is just the opposite. In addition, the size of fracture-block is related to fracture modes.