Principle of Operation:
The continued improvement of high energy rare earth permanent magnetic materials has contributed to an unprecedented acceptance by several industries of rare earth permanent magnetic separators. The evolution of these high strength permanent magnets has led to the development of high intensity separators that operate energy-free. The Rare Earth Roll separator was designed to provide peak separation efficiency and is typically used when a high level of product purity is required. The roll's permanent magnetic discs alternating with thin steel pole pieces along a shaft. The steel poles are saturated with magnetic flux and produce a magnetic field in excess of 21,000 gauss.
The Rare Earth Roll is used as a head pulley, and a thin belt connects the roll to a Dynaloc, self cleaning tail pulley. The standard belting is Teflon coated, graphite filled KEVLAR with thickness of 5 and 10 mils. Accepted belting is also available for food and pharmaceutical applications. The belt conveys the feed material to the magnetic field or separation zone. When the feed enters the magnetic field, the magnetic and/or paramagnetic particles are attracted to the roll while the non–magnetic material follows the natural discharge trajectory. A splitter arrangement is used to segregate the two streams. Other components of the Rare Earth Roll separator include a vibratory feeder with a mounted hopper, stainless steel product discharges, TEFC gearmotor and controls. The rare earth roll separators are avail- able in single, double and triple stage versions with either non–magnetic or magnetic rerun.
Applications:
The Rare Earth Roll separator has been accepted by a number of industries as the most effective magnetic separation method
for the purification of non–magnetic materials. These industries and their specific applications are listed below.
Industrial Minerals
Effectively reduces the level of iron from beach sands, feldspar, silica sand, calcium carbon- ate, magnesite, kyanite, bauxite, andalusite, etc. by removing iron bearing minerals such as hematite. Magnetically concentrates weakly magnetic minerals, such as garnet, ilmenite, musovite, mica, etc.
Abrasives
Extremely high levels of product purity are obtained by removing the very fine iron of abrasion and iron smeared on the abrasives. Specific abrasive material treated includes aluminum oxide, silicon carbide, glass beads, tumbling media.
Plastics
Iron and/or stainless steel encapsulated in pel- lets are effectively removed from the product stream. Free stainless steel and very fine iron is also removed with very high levels of efficiency.
PVC
PVC flakes can also be treated to remove iron smeared flakes from uncontaminated product.
PET
RE Rolls are also utilized to scalp 40% to 70% of aluminum from shredded PET soda bottles that use aluminum caps.
Food and Pharmaceutical
Effectively removes rust from free flowing, granular chemicals and dehydrated vegetables.
Recycling
The RE roll is capable of sorting the nickel and cobalt bearing metal turnings from titanium or zirconium metals. Other applications include removal of shredded aluminum from PET, separation of chrome from crushed automobile grills, and sorting of paramagnetic, synthetic diamonds from natural diamonds.
Other Industries
Glass, foundries, specialty materials and metals, electronics.