mining, Metallurgy and Petroleum Engineering, Amirkabir University of Technology
The occurrences of huge reserves of garnet deposits have been reported from different parts of Iran specially those of Kohe-E-Gabri area which is very high grade in nature. These deposits can not be directly used as abrasives, filter aid and many others because of some impurities present. To know the mineralogical composition, the type of garnet, the shape of the particles, the chemical character and the mesh of the grind all of which play a vital role in finding out suitable flowsheet design, the samples have been subjected to detailed mineralogical and microscopic studies, sieve analysis, liberation studies and chemical analysis. The results indicate that, the type of garnet is anderadite with relative grade of 75% and most of the particles shape are of edged type rather than rounded one and this is to be taken in to account while using them as abrasives and filter aids. Quartz, Calcite, Wollastonite, Magnetite and Hematite are the impurities present in the order of abundance and liberation studies show that the optimum mesh of the grind is about 600 microns. Based on the characterization studies, it was suggested that the gravity and magnetic methods would be the suitable separation techniques for removing the impurities. Therefore, the beneficiation studies have been carried out with, table, spiral, multigravity and magnetic separators. In all gravity techniques due to higher specific gravity of magnetite, this particular mineral has been separated with garnet in concentrate which is removed later with a magnetic separator. Finally based on the preliminary characterization and beneficiation studies, it's possible to upgrade the garnet deposits of Rafsanjan area to the tune of more than 95% garnet with recovery of above 87%. The results obtained are not only encouraging but also form original and distinct contribution to the beneficiation of garnet in general, and to that of Kohe-E-Gabri area in particular.