Numerical and experimental studies of the effect of iron ore particle shape on repose angle and porosity of a heap

Spherical (pellet), cylindrical and conical iron ore particles were produced to study the effect of particle shape on repose angle and bottom porosity distribution of a heap formed by natural piling. The effects of coefficient of static friction, rolling friction and restitution and particle shape on the repose angle and porosity of the pile for three particle shapes were numerically studied by the discrete element method. The results show that the primary influential factors on repose angle and porosity is the static friction, followed by particle shape. The repose angle of piles of spheres is smaller than that of non-spheres, but there is little difference in repose angle between non-spherical particles. The value of the porosity in the three kinds of piles decreases from spheres to cones to cylinders, but all show a V-shape distribution, with lowest porosity along the axis through the apex. The porosity shows a minimum value when the sphericity is about 0.85. Piles of cylindrical particles show the smallest porosity due to parallel planes of the particle shape. (C) 2019 Elsevier B.V. All rights reserved.