Streamlining Material Separation and Classification With Hydrocyclones

Hydrocyclones are relatively straightforward machines, yet require process knowledge for their optimal usage. Their cylindrical upper section features an involute-shaped inlet for feeding material into them as well as a cone and spigot discharge point.

Size the cyclone according to desired centrifugal force and cut point using specialized software called CY-i.

High Efficiency

Hydrocyclones use centrifugal force to separate particles in liquid by creating a vortex when fed slurry into the device, and finer material flows out through its overflow while coarser ones pass into its underflow, producing what’s known as the cut point for separation.

Effective cyclone operations allow up to 70% of liberation sizes to report to the overflow. While this figure will depend on your process, a worn apex may reduce efficiency by increasing ultrafine by-pass that reports back underflow.

Multotec’s experienced process team can perform a CY-i hydrocyclone sizing for you, to ensure it fits the appropriate centrifugal force and cut point requirements for optimal operation of the cyclone. This will eliminate roping that could harm downstream operations while increasing system efficiency overall. Furthermore, input solids levels must remain constant to avoid changes affecting performance of cyclone significantly.

High Capacity

As soon as feed slurry enters the lower conical section, it begins to spiral around a vortex and drag along material which causes separation into finer fractions and coarser material as it leaves through overflow and underflow. At its spigot/apex lies an air core for optimal operation based on solids expected. If an oversized apex occurs instead, excess overflow (roping) could occur which would affect performance adversely.

Air core maintenance is crucial in order for cyclones to work as intended and achieve desired size separation, and understanding how apex/spigot size affects classification performance of cyclones is therefore of utmost importance.

Low Maintenance

Hydrocyclones use centrifugal force to sort particles by size and density. Larger or heavier particles fall to the bottom (underflow), while finer, lighter materials rise up through the device (overflow). This allows maximum recovery while decreasing waste streams.

Metso has designed its MHC Series hydrocyclone with an internal geometry to promote smooth flow from inlet to discharge for minimum turbulence and maximum separation efficiency, along with numerous material choices to balance wear performance with cost.

Regular inspections should be conducted to remove accumulated solids or blockages that impede separation performance, and keeping a record can help identify trends or problems and serve as a reference point for future maintenance activities. When upgrading, consult with professional installers regarding available upgrades that will enhance wear resistance and separation efficiency through changes to design or material, or both.

Versatility

Hydrocyclones are widely utilized throughout the mining industry to achieve various objectives such as desliming, degritting, concentration, classification and recovery of fines from grinding circuits. While these cyclones are usually found in hard rock or precious metal processing applications, they can also be used to dewater slurry or separate fines from effluent streams.

Operating this unit involves feeding higher density particles via the flow stream to an apex or spigot at its top, where they are carried downward by centrifugal force until reaching a Vortex Finder and being discharged. Coarser material then reports via overflow line to be further processed through flotation system.

Multotec’s experienced team can use CY-i, our dedicated software, to size each cyclone to your specific centrifugal force and cut point needs, increasing d50c while increasing overall capacity of your cyclones while decreasing wear in transfer zone by minimising turbulence – leading to longer maintenance intervals, lower energy consumption, and improved production rates.