Performance improvement of the Sarcheshmeh Copper Complex Cu-Mo thickener using a vane type feedwell

Water plays a key role in mineral processing plants. In order to process one ton of ore, 2.5 ton water is needed. Thickeners are commonly used for dewatering and recovering the water in most mineral processing plants. The underflow pulp density is increased by the sedimentation of particles and a clear water is then recovered from the overflow. One of the issues related to using the process water (thickener overflow) is the presence of suspended fine particles which create blockage in transfer pipes. The froth formed on top of thickeners is the main cause of this problem. In this study, a method is introduced and implemented to decrease the froth formed on the Sarcheshmeh Cu-Mo thickener surface. First, the old punched plate feedwell was removed and replaced by a vane type feedwell. A spray water ring was then installed using fish-tail type nozzles to break the froth layers by water. These modifications led to 63% relative reduction in the water turbidity, 11% relative increase in the underflow solids concentration, 20% relative reduction in torque, 19% relative reduction in its standard deviation and an increase of 6% in the water recovery.