摘要：

Closing down iron ore mines due to environmental constraints spurred the iron ore washing plants to recover the values from their slimy tail pond. The paper enumerates the developments in ecofriendly processing of iron ore slimes by state of art vertical pulsating wet high intensity high gradient magnetic separation. The wash plant tails assayed 46.45%Fe, 18.03%SiO 2 , 5.25% Al 2 O 3 , and 6.10%LOI. The process comprises of high pressure cycloning of dispersed pulp to remove slimes less than 10 microns. The cyclone under flow is subjected to vertical pulsating high intensity high gradient magnetic separation at 8200gauss [ open air intensity] 35% Solids pulp density followed by cleaning at 7000 gauss in [open air intensity] 15% solids. The concentrate is thickened and filtered in lab Larox pressure filter. The above process produced a concentrate assaying 64.00% Fe, 2.41% SiO 2 , 2.51% Al 2 O 3 , 1.90%LOI,-150 mesh size and 8.6% moisture with 30% Fe recovery at wt% yield of 20.0 meeting the requirements of on line pelletization plant. Locked cycle test by desliming at 5 microns and the recycling the cleaner tails back produced the concentrate assaying 62.89%Fe with 35% Fe distribution at wt% yield of 26.1. The concentrate marginally failed to meet the chemical specifications stipulated and cycloning to remove-5 microns content was not practically feasible in industrial operations and hence dispensed with. Detailed on site pilot plant tests are recommended as the process appears economically and ecologically feasible and can be retrofitted as tail piece in the existing washing plants.

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