TECHNOLOGY •
ADVANCEMENTS IN DRY HIGH- INTENSITY RE ROLL MAGNETIC
SEPARATORS EXPLORED
By Jose Marin , Eriez ® director – Minerals and Materials Processing
The Dry High Intensity Rare Earth ( RE ) Roll Magnetic Separator is a pivotal tool in the pursuit of innovative improvements , efficiency and competitiveness in magnetic separation .
The ever-growing demand for higher purity industrial minerals , fuelled by emerging global applications , poses a challenge for producers dedicated to delivering quality products . Yesterday ' s production runs are no longer sufficient in meeting ever-evolving requirements . To stay ahead , companies should embrace technological advancements and explore state-of-the-art equipment that opens doors to new applications in dynamic markets . In this context , magnetic separation emerges as a crucial technology , offering substantial enhancements in product and mineral quality through increased recovery . Manufacturers of magnetic separation equipment are actively pursuing improvements and efficiency gains across processes to stay competitive and innovative . A pivotal tool in this pursuit is the Dry High Intensity Rare Earth ( RE ) Roll Magnetic Separator .
Next generation RE roll separator Rare earth roll separators effectively replaced the induced magnetic roll separators ( IMR ) because of the equipment ’ s simple , compact design and low power consumption . Its performance was as good or better than that of the IMR .
Early models were manufactured with Samarium Cobalt Rare Earth magnets and the maximum roll width at the time was 40 inches ( 1m ) wide . The width of evolved units since have increased to 60 inches ( 1.5m ), and now , Eriez has announced the development of an 80 inch ( 2m ) wide RE Roll .
The Rare Earth Roll , generating peak magnetic field strengths approaching 24 000 gauss , is highly effective for concentrating or removing weakly magnetic minerals from a dry process stream . The Rare Earth Roll magnetic separator is designed to provide peak separation efficiency and is typically used when a high-purity product is required . To this end , the roll is constructed from discs of neodymiumboron-iron permanent magnets sandwiched with steel pole pieces . The steel poles are magnetically induced to the saturation point of approximately 24 000 gauss .
Jose Marin , Eriez director – Minerals and Materials Processing .
Magnetic roll diameters are typically 3 , 4 and 6 inches wide , although separators as large as 12-inch diameters are available . The separator is configured as a head pulley in the unit . A thin belt , usually from 5 – 20mm thick is used to convey the feed material through the magnetic field .
The completely re-designed 80-inch wide RE Roll features housing upgraded from conventional welded construction to an innovative “ bolt on ” design . The cantilever assembly has also been updated and now incorporates fewer components . These improvements enable the 80-inch RE Roll to provide improved durability and extended service life .
Bearing replacement has been simplified so operators do not struggle with the weight of a magnetic roll that will be magnetically attracted to any metallic part on the machine and nearby area . The belt tracking mechanism has also been simplified to make the belt replacement procedure even faster than previous models – Kevlar belts are still the longest lasting belts , and belts with diagonal splices as well as finger splices are also available .
High intensity RE roll .
Images supplied by Eriez www . africanmining . co . za African Mining Publication African Mining African Mining • March 2024 • 17