USE OF SURFACE-AREA AND POROSITY TO CHARACTERIZE THE CHEMICAL UPGRADING OF ILMENITE

Mechanical milling, chemical attrition and various leaching processes modify the surface and physical properties of ores, and ultimately inf luence their behaviour during processing. Measurements of surface area and porosity can assist in understanding the behaviour of, and optimi zing the upgrading of, finely divided problematic ores. During the upg rading of titanium-bearing mineral sands, iron-rich coatings on the mi neral particles often impair the concentration of individual component s. Owing to their porosity, these coatings have a significant surface area compared with the other sand constituents. The effect of leaching of ilmenite samples is described in terms of surface area, pore volum e and pore size distribution. These physical measurements show that th e oxide coatings are eroded into mesoporous regions in the diameter ra nge 50 to 700 angstrom, and become weakened. This structural weakening enables the coatings to be easily removed by attritioning.