Table of Contents
Magnetic and Electrical Separation
Volume 11, Issue 1-2, Pages 33-50
http://dx.doi.org/10.1080/07313630290002572

The Concept of Magnetic Mineral Separation by Particle Rotation

Ka Pty Ltd., 14 Station Lane, Exton, Tasmania 7303, Australia

Received 17 July 2001; Accepted 23 July 2001

Copyright © 2002 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

At present all magnetic separators use particle attraction as the separating criterion. Differences in magnetic susceptibility then determine whether or not two mineral particles can be magnetically separated. Some separators, such as the Magstream separator, have gone a step further and combined magnetic attraction with particle specific gravity.

Mineral particles have a second, largely ignored, magnetic property that can be used as a separating criterion, and this property is particle rotation. Particle rotation applies mainly to ferromagnetic minerals, and therefore separation by magnetic particle rotation is practical only for ferromagnetic particles or particles with ferromagnetic inclusions.

Particle rotation separation, in which particles are separated only if they can be magnetically rotated, is not a replacement for conventional magnetic attraction separation. Rotation separation is intended for applications where there are two different minerals with different magnetic anisotropy, or where compositional differences within the one mineral species lead to differing magnetic anisotropies.

Particle rotation separation has applications in diamond exploration where it allows the magnetic concentration of indicator minerals, and in mineral sands separation where it can provide high ilmenite recoveries with very low chrome content.