Table of Contents
Physical Separation in Science and Engineering
Volume 12, Issue 3, Pages 167-178

The Effect of Magnetic Field on the Performance of a Dense Medium Separator

1TSS Technology, De Beers Consolidated Mines (Pty.) Ltd., P.O. Box 82851, Southdale, Johannesburg 2135, South Africa
2Namaqualand Mines, De Beers Consolidated Mines (Pty.) Ltd., Private Bag X01, Kleinzee 8282, South Africa

Received 21 July 2003; Revised 25 August 2003; Accepted 3 September 2003

Copyright © 2003 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.


The application of a vertically oriented magnetic field external to a dense medium cyclone can be used to manipulate the density differential within the cyclone by influencing the cyclone's internal ferrosilicon distribution. Tests were conducted on a well-defined dense medium system using a pilot-plant cyclone equipped with a solenoid magnet. The objective was to determine the yield to the dense medium cyclone underflow of a sample consisting predominantly of quartzite material, as a function of the magnetic field strength of the solenoid magnet, and as a function of solenoid position. It was observed that for a specific selection of magnetic field strength and solenoid position, the concentrate yield was reduced. A decrease in yield to concentrate is advantageous in that it reduces the mass of material to be processed downstream. The yield reduction was found to be a function of the applied magnetic field strength. Furthermore, it was found that a disruption in the ferrosilicon flow pattern inside the cyclone may occur beyond a certain magnetic field strength which leads to impaired cyclone operation.