Table of Contents
Physical Separation in Science and Engineering
Volume 12 (2003), Issue 2, Pages 103-121
http://dx.doi.org/10.1080/1478647031000152489

Effect of Roasting Temperature on the Magnetism of Ilmenite

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

Received 26 February 2003; Revised 4 March 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.

Abstract

The enhancement of ilmenite magnetic susceptibility by roasting is well known, and it is used routinely in the magnetic separation of mineral sands, yet surprisingly little appears to be known in detail about the development of this magnetisation as roast temperatures increase. An examination of the changes in both magnetic susceptibility and magnetic rotatability within the roast temperature range 350–650°C reveals some interesting low-temperature magnetisation changes. The results suggest the presence at low roast temperatures of very small magnetised regions that behave as though they are superparamagnetic, and suggest that the growth of these regions plays a significant part in the development of roast-induced magnetisation. The results also show that the bulk magnetic development above 500°C is a resultant of several temperature-dependent competing processes.