Solution collection design issues on large heap facilities

Solution collection is one of the most important issues in heap leach facility design. The solution collection system must be able to efficiently collect solution for processing over the life of the facility. Large heap leach facilities can present challenges to the design and operation of solution collection systems. Large heap leach facilities often have very high ore loads (well over 100 meters of stacked ore) which can adversely impact the performance of the solution collection system. High ore loads may cause significant foundation settlements, thereby changing the drainage characteristics within the heap. High ore loads may also damage or collapse solution collection pipes. In addition, the hydraulic properties of the ore may change with increasing ore load or height. This paper presents discussions on solution collection design issues as they relate to large heap leach facilities. Topics covered in this paper include foundation settlement, solution collection pipe stability under high heap loads, and ore hydraulic properties within high heaps. Design approaches are presented to address each of these topics.