Investigative determination of rod matrix in pulsating high gradient magnetic separation of ultrafine hematite tailings

A mass of ultrafine weakly magnetic iron minerals are produced during the processing of iron ores such as hematite and limonite, and in the most cases these fine minerals are recovered at a very low efficiency, especially for the magnetic particles below 20 mu m. Pulsating high gradient magnetic separation (HGMS) of rod matrix is comparatively investigated for the processing of an ultrafine hematite tailings (around 65% below 20 mu m), to determine the optimum rod matrix for the recovery of ultrafine hematite minerals from the tailings. The results of investigation indicate the finest 1 mm rod matrix achieved the most effective processing of the tailings assaying 28.99% Fe, produced a concentrate assaying 46.85% Fe with 59.39% recovery at a low magnetic induction of 0.5 T, and these are much superior to those of the 2 mm and 3 mm rod matrixes.