In use as an essential classification and dewatering tool for the best part of 90 years, today hydrocyclones play a key role in maintaining concentrator flow. E&MJ looks at the technology fundamentals and how equipment optimization is still in progress.
By Simon Walker, European Editor
Although simple in concept, the hydrocyclone fulfils an essential role in both classification and purification across a wide range of industries. Mineral processing is no exception, with cyclones often being an integral part of closed-circuit grinding systems.
The centrifugal force applied to particles being spun within a cyclone is many times greater than gravity, allowing the device to achieve a much better separation efficiency based on either (or both) particle size and density. Larger or more dense particles are directed toward the underflow, while finer or lighter material reports upward to the overflow. The better design of the cyclone, and the less wear there is internally, the less opportunity there is for larger particles to be misdirected to the overflow, or for slimes to sink into the underflow. In a typical closed-circuit grinding system, the consequences of either situation can have a significant impact on operating economics.