Liquid spread mechanisms in high-temperature underground stope leaching

Abstract

Liquid flow behavior is a key factor that affects the leaching rate and metal extraction of stope leaching (SL), but related experimental studies are very limited. The liquid spread mechanism of SL is complicated because of the high-temperature conditions, the structural characteristics of the stope, and the pore characteristics of the ore heap. In this study, a device was developed to investigate the liquid spread mechanisms of the upper wall and foot wall of the stope. The influence of temperature, dip angle, and flow rate on the liquid spread was investigated. It is shown that the most significant feature of liquid spread in a stope is the liquid flow towards the bottom of the stope vertically rather than horizontal liquid spread. The increase of temperature accelerates the liquid spread, leading to the emergence of preferential flow paths. When the dip angle decreased from 90° to 60°, the liquid spread along the foot wall increased, including the change of the preferential spread direction, though the initial wetting time of the upper wall decreased. Increasing the flow rate within a certain range does not result in a more obvious liquid preferential flow path. Although the liquid spread of stope leaching still requires more studies in detail, the results of this work could be helpful to understand industrial stope leaching mechanisms.