Effects of ore shape on pore structure and seepage velocity field in heap leaching

In order to investigate the effects of ore shapes on pore structure and seepage velocity field in heap leaching, column leaching experiments was conducted with pellet ore and crude ore in the same particle size distribution.The internal saturated structure was obtained in a non-contact way with MRI, then the relationship between ore shape and pore distribution was studied through image processing and statistics.And the Navier-Stokes equations are used to simulate the flow velocity field and the dominant flow distribution in different ore shapes under the same pressure and infiltration velocity.The results show that not all internal pores obey with normal distribution, the pore size distribution between pellet ores obey the normal distribution based on the statistical analysis, and the μ=2.0 mm; pore distribution between crude ore does not obey the normal distribution, there is a missing from 8.00 mm to 11.00 mm, and the maximum equivalent diameter is 1.39 mm.In the pellet ore field the velocity distributes more evenly, and there is no obvious dominant flow; but in the crude ore field, the velocity field distribution is not balanced, and there is a distinct dominant flow and a large leaching dead zone, and the flow at the exit boundary presents coupled flow field.The effect of ore shape on the internal pores and seepage can be described by uniformity coefficient (K) effectively, the distribution of pores and seepage velocity is balanced when K value is small, when K value is large, it is easy to appear large connected pores, which is the dominant flow channel, resulting in the uneven flow field distribution.