Wet drum separators are used in Dense Media Separation (DMS) plants for the recovery of magnetic particles from the dilute medium. They must recover the maximum amount of magnetic particles at the highest possible density.
A wet drum separator consists of a feed box where slurry in initially introduced to the separator, this slurry is then presented to the magnet drum via feed pipes.
The magnet drum consists of a stationary magnet arc around which a drum rotates. The drum is partially submerged in the tank. When the ferromagnetic [medium] particles in the slurry are introduced into the magnetising field produced by the magnet, they first align themselves with the lines of force. The individual magnetic particles are magnetised as they enter the magnetic field. They become induced magnets and join together to form chains or agglomerates which are attracted to the drum. The attraction of magnetic particles to each other increases with the amount of magnetic particles in the feed. When the magnetic force acting on the flocs exceeds the opposing forces, the flocs attach themselves to the drum surface. Flocculation occurs more readily with a “thick” slurry than with a “dilute” slurry, where the magnetic particles are far apart from each other.
The drum contains an axially arranged rare earth magnet assembly with alternating magnet poles (north/south) this provides a very strong magnetising field intensity and high magnetic gradient of 4000 or 6000 gauss at the feed point.
In a counter rotation [CR] tank the drum direction is moving against the feed direction and weakly magnetic particles are attracted to the drum surface and immediately discharged into a chute under the feed box as the moving drum and particles are transported out of the very strong magnetic field.
Non-magnetic particles / grit and water which are unaffected by the magnetising field, leave the tank through the tailings discharge outlet and weir overflow.
Level control in the tank is provided by use orifice insert rubbers, restricting the water flow form the tank increases level further submerging the drum and removing them increases outflow reducing the slurry level in the tank.
The medium intensity wet drum separators will perform the following:
Removal of paramagnetic particles from materials being processed in slurry form
Removal of chromite from heavy mineral concentrate.
Typical particles size range separated range from 30 microns up to 3 mm
High Magnetic Gradient and flux density on the drum surface using Rare Earth [NdFeB] magnets in an axial alternating pole arrangement.
4000 gauss and 6000 gauss SUPRSEP designs available
Able to recover very fine paramagnetic particles in slurries
High concentrate densities easily achieved
Maintenance friendly drum components, sealed for life drive end bearing, non-drive bearing can be changed “in-situ
Advanced drum component sealing and ingress protection arrangement
Modular magnet element using support column instead of solid shaft, detachable stub shafts on either column end
Direct Drive Shaft mount helical bevel geared motor drive arrangement on detachable drive shaft, low maintenance and easily detachable
Non-drive side drum bearings required re-lubrication; non-drive bearing can be changed “in-situ”. The drive side is “lubricated for life”
Self-Tensioning Scraper Blade assembly
Can be supplied with various optional parts and configurations (feed manifolds, product chutes, launders, wear wraps, guarding)
Permanent Magnet drum with Rare earth permanent magnet
Shell carried on end flanges fitted with sealed, self-aligning bearings. The shell is made from non-magnetic stainless steel, typically 3 mm thick. The shell can be covered with an optional wear wrap, typically 2 mm thick, of non-magnetic stainless steel or polyurethane. The drum end flanges are machined from non-magnetic stainless-steel plate.
The feed box and tank (underpan) are an integral construction, fabricated from non-magnetic stainless steel, typically 3 mm thick. The concentrate chute and feed box are lined with polyurea spray on lining.
The support frame is fabricated mild steel sections and painted with a 2 coat epoxy paint system.
The helical bevel shaft mounted geared motor drives the drum directly coupled to the end flange via a stub shaft.
Drum scraper blade assembly for cleaning any carried over concentrate
