Plugging mechanisms and plugging reduction techniques in heap leaching operations: a review.

Abstract: Plugging of pore spaces is the most significant contributor to ponding, decrease in the mineral resource recoveries and stability problems in heap leaching operations as ore permeability is reduced. Consequently, the identification of different plugging mechanisms is very important for optimisation of heap leaching processes. This paper reviews various pore spaces plugging mechanisms, including ore heap compaction, migration of fine particles, presence of large fractions of clays in ores, agglomerate destruction under acid effect and dissolution-precipitation processes. Proactive plugging reduction techniques including ore placement, ore agglomeration, heap aeration and lixiviant application techniques are also explained as means to prevent pore spaces plugging during heap leaching operations. The findings of this paper can be useful in guiding laboratory and industrial heap leaching operations