260 / 2018-03-16 10:25:49

Numerical Simulation of Dust Movement Regularities and Affecting Factors at Slope Drilling in Open-pit Mine

slope drilling, dust concentration distribution, mathematical model, gas-solid two-phase flow, numerical simulation

矿山职业健康与环境安全 > 防尘毒

Based on the gas-solid two-phase flow theory, it is practical to carry out a force analysis of dust in the wind and build a three-dimensional mathematical model of dust motion, which is conducive to improving open-pit mine slope drilling perforation operation, exploring the main factors that influence the dust concentration distribution and obtaining various parameters setting of low dust concentration distribution in mine stope. For instance, in the slope drilling perforation operation of a large iron mine, the software Fluent of the computational fluid dynamics can be applied to numerically simulate the dust concentration distribution. By comparison, its results basically tally with the measured results which have verified the three-dimensional mathematical model of dust motion in open-pit mine slope drilling perforation operation. The results show that, when the perforation starts, dust particles under the action of compressed air are ejected from the hole-bottom to the orifice. They will longitudinally diffuse along the wind direction and transversely pulse in a random way in mine stope. The dust concentration increases with time at the beginning. When reaching a certain value, it keeps stable and fluctuates within a certain range. The dust concentration increases sharply at first along the measuring point line. When reaching the maximum, it drops rapidly to a relatively small value. Subsequently, it is followed by a gradual slow decrease. The dust concentration is lowest with wind velocity 3.5 m∙s-1, supply pressure 1 MPa, drilling depth 12 m and drilling machine speed 84 r∙min-1.