Thickening is a process where a slurry or solid-liquid mixture is separated to a dense slurry containing most of the solids and an overflow of essentially clear water (or liquor in leaching processes). The driving force for the separation is gravitational, where the differences in phase densities drive the separation of the solids and liquid. In mining applications, thickening through sedimentation is applied to both the product and tailings streams to recover water. This water is recycled in the process(Beginners Guide to Thickeners, n.d.).
Thickening is carried out in a sedimentation tank or in a sedimentation pond. The latter is advantageous if land area is available, because the sludge can be allowed to settle over a much longer period and a higher solids content of the thickened sludge is achieved. The water removed from thickening needs treatment. It can be returned to the inlet of an off-site wastewater treatment plant, or in the case of sludge from on-site units by an aerobic treatment process(Thickening, Dewatering and Drying, 2016).
Thickening (sedimentation) plays a crucial role in mine dewatering. What are the key principles behind this stage, and what happens to both the water and the settled solids afterward? Let’s explore this essential step!
References:
Beginners guide to thickeners. (n.d.). Metso. Retrieved May 13, 2025, from https://www.metso.com/insights/blog/mining-and-metals/beginners-guide-to-thickeners/
Thickening, dewatering and drying. (2016, August 5). https://www.geo.fu-berlin.de/en/v/iwrm/Implementation/technical_measures/Wastewater-treatment/Sludge-treatment_-reuse-and-disposal/Thickening_-dewatering-and-drying/index.html
