Characterization and beneficiation of iranian low-grade manganese ore

The mineralogical studies indicated that the Charagah ore deposit contains approximately 17% pyrolusite, 78% calcite and 3–4% quartz. Pyrolusite as a main valuable mineral is found in the forms of coarse and fine pyrolusites. The coarse grains pyrolusite with simple texture is liberated at 180 micrometers. Another kind of pyrolusite with particle size finer than 10 m is disseminated inside gangue phases. This kind of pyrolusite has important effect in beneficiation processes and can affect the manganese grade of the concentrate and its recovery negatively. By jigging machine a pre-concentrate with 20% MnO and a final tailing with about 13% manganese loss are obtained. Using tabling technique or wet high intensity magnetic separation (WHIMS) and also their combination with jigging machine, production of a final pyrolusite concentrate with suitable grade but average recovery is possible. By jigging-tabling a concentrate with – 500+45 m size fraction, 44.3% MnO and 61.3% recovery is obtained while jigging-WHIMS produces a concentrate containing 52.6% MnO with a recovery up to 56.6% and d80 = 180 m.