Abstract

Individual ilmenite particle measurements of magnetic susceptibility and magnetic rotation index show that, as ilmenite roast temperatures increase, both the magnetic anisotropy and the coercive force increase. By around 650°C the particles are behaving magnetically, in magnetic fields up to 0.3 T as though they contain magnetic elements with a single unidirectional magnetic axis.The presence of some magnetic field, even that of the earth, during the cooling of ilmenite samples roasted above 500°C may be essential to the magnetising roast process.