高海水围压条件下多金属硫化物的破碎机理

摘要

为研究高海水围压条件下截齿在切削海底块状多金属硫化物(SMS)过程中的破碎机理,考虑海底块状硫化物高孔隙率、非线性的特点,选择Holmquist-Johnson-Cook(HJC)材料本构模型,基于Lagrangian有限单元法,利用LS-DYNA仿真软件建立截齿切削破碎海底块状多金属硫化物的仿真模型,模拟无海水围压下和高海水围压下海底块状多金属硫化物的切削破碎过程.研究结果表明:在高海水围压作用下,海底块状多金属硫化物的强度明显提高,断裂模式主要是脆性失效向塑性失效转变;海水黏着力和高围压作用使得切屑更难从矿体基岩剥离,截齿受到的阻力明显增大.%In order to study the breaking mechanism of seafloor massive sulfide(SMS) under high deepwater confining pressure, the Holmquist-Johnson-Cook (HJC) material model was adopted in consideration of the high porosity and nonlinear material behavior of SMS.Based on Lagrangian finite element method, a simulation model for cutting SMS of point-attack pick was established by using LS-DYNA. The whole dynamic cutting process with or without high deepwater confining pressure was simulated. The results show that under high deepwater confining pressure,the failure strength of SMS increases significantly and the cutting process is transformed from brittle fracture mode to ductile fracture mode. The viscosity of the water and high confining pressure reduce the speed at which the chip can leave the host orebody and results in higher cutting forces.