Technical Explanation of Rare Earth Roll Separator

By Paul Fears | 27 March 2019

The Rare Earth Roll Separator is one of the world’s most popular permanent magnetic separators used by mineral processors to separate paramagnetic minerals from dry materials.  The Rare Earth Roll Separator is simple to install and use, whilst being exceptionally energy-efficient.  The high-intensity magnetic strength enables the separation of very weakly magnetic minerals such as mica (biotite and muscovite).  The high intensity magnetic fields are generated using permanent Neodymium Iron Boron Magnets, otherwise known as Rare Earth Magnets.

Rare Earth roll
Rare Earth Roll Separator

The Applications

The Rare Earth Roll Separator is used to separate weakly or para magnetic minerals from non-magnetic minerals in a dry state.  These non-metallic minerals are widely used in the production of ceramics, plastics, glass, cosmetics, paper, and many other commonly used materials.  Typical minerals being processed include feldspar and silica sand.

The Methodology

In our latest video, Professor Neil Rowson, a respected mineral processing engineer from the University of Birmingham, presents a technical video explanation of the Rare Earth Roll Separator.

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In our video, Prof Rowson explains how the untreated non-metallic mineral material is fed from a hopper or vibratory feeder at a controlled rate onto a short conveyor.  The mono-layer of material is carried onto a high intensity permanent magnetic head roll.  Magnetic material is attracted to the magnetic field of the roll.  This attraction changes the trajectory of the magnetically attracted minerals away from that of the non-magnetic material.  A splitter plate is positioned between the two different trajectories, enabling a split of the two materials and separation of  the weakly and para-magnetic minerals.

The separation is continuous and requires limited supervision.  Rare Earth Roll Separators are often supplied as multi-stage systems with materials (feed or separated magnetics) being retreated.

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Technical Video Presentations

Several technical video presentations by Professor Neil Rowson on the use of high-intensity magnetic separators in the minerals industry are available to view on the Bunting-Redditch website:

Related Mineral Processing Technical Articles

Magnetic Separators – Mineral Processing Laboratory

Bunting-Redditch has one of the most comprehensive magnetic separation mineral processing testing laboratories in the world.  Their Laboratory Technicians have decades of experience in mineral processing.  Controlled tests ensure that the most suitable and cost-effective machinery is recommended for each application.  The laboratory is equipment with a wide range of equipment including:

  • Smaller scaled versions of industrial Magnetic Separators.  This equipment is used to accurately scale up to industrial capacities and calculate performance guarantees;
  • X-Ray Fluorescence and X-Ray Diffraction analysis are available for chemical assay and mineralogical identification to aid the development of a viable process route for each application;

For further information on our range of magnetic separation equipment designed for purifying ceramics and non-metallic minerals, or to arrange sample tests in our laboratory, please contact us on:

Email: Gordon Kerr at

Via the website

Telephone:  +44 (0) 1527 65858

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