Abstract

The application of high–gradient magnetic separation to the beneficiation of oxidised iron quartzites is complicated by the presence of a wide range of magnetic properties associated with fine dissemination of iron–containing minerals. It has been observed that an increase in the recovery of iron and in the grade of the concentrate can be achieved by controlling the magnetic susceptibility of the slurry by avoiding the overgrinding of the ore. In this way the recovery of iron has been increased by 3% and the grade of the concentrate by 2.3%.