Performance evaluation of magnetic separation circuits for units number 2 and 6 of Sangan iron ore complex

The evaluation of a magnetic separation circuit can be used to determine its working efficiency, and formulate new strategies for its future performance improvement. The aim of this research is to do performance evaluation for units number 2 and 6 of the magnetic separation circuits in Sangan iron ore complex. In both units, the run of mine ore is crushed and divided into coarse (10-30 mm) and fine (0-10 mm) sized fractions, and then each fraction proceeds to a dry low intensity magnetic separation circuit. Totally, 270 samples were taken from four magnetic separation circuits and the samples were analyzed for total iron, iron oxide (FeO) and sulfur content. The results indicated that the average Fe grade of the final product of all magnetic separation circuits was more than 57%. The average iron recoveries in the fine and coarse magnetic separation circuits for unit number 6 were 92.29 and 78.93%, and for unit number 2 were 69.25 and 55.36%, respectively. The iron recovery of coarse magnetic separation circuits is lower than that of fine circuits which is due to a lower magnetic field intensity of separators in these circuits. This is for maintaining the suitable iron grade of concentrates desspite the lower degree of freedom in the feed. The iron recovery in both magnetic circuits of units number 2 is lower than that of units number 6 which is due to inappropriate feed and operating conditions of the magnetic separators in this unit.