Table of Contents
Magnetic and Electrical Separation
Volume 7, Issue 3, Pages 163-184

Magnetogravimetric Separation in a Rotational Device

1Department of Materials Science and Mineral Engineering, University of California, Berkeley CA 94720, USA
2BMG Engineering AG, Ifangstrasse 11, Schlieren, Zurich 8952, Switzerland

Received 11 November 1995; Accepted 2 February 1996

Copyright © 1996 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.


Magnetogravimetric separation in a rotational device is a promising method for effecting sharp separation of minerals according to density. Separation is accomplished by two competing forces with opposite directions, namely the magnetic buoyancy and the centrifugal force. Magnetic buoyancy is experienced by particles which are suspended in a magnetic fluid when exposed to a non—homogeneous magnetic field. Since the magnetic buoyancy depends on particle volume whereas the centrifugal depends on particle mass, a purely gravimetric separation of non—magnetic particles can be accomplished. The process is able to achieve separation split—points up to densities of 20 g/cm3, but separation sharpness decreases with fine particle sizes. On a laboratory scale, magnetogravimetric separators can be used as an alternative to heavy liquid separation, and in industrial plants they may have promise as the final cleaning stage in gravity concentration circuits of precious metals.