The beneficiation potential of the iron ore slimes produced from the washing plants and tailing ponds of Kiriburu mines assaying up to 60% Fe, 3.34% SiO2, and 2.93% Al2O3 is analyzed. To start with, the ore slime was characterized in sufficient detail to reveal that it is extremely fine 80% below 110 mum and contains substantial amount of goethite (Fe2O3.H2O). The liberation study indicates that the finer particles (-45 mum) are less liberated than the coarser particles. Taking into account all the physical and chemical attributes of the ore, a two-stage hydrocyclone-spiral circuit was envisaged for processing the ore. At first, the performance of this circuit was assessed through simulation using MODSIM - a modular simulator for ore dressing plant flow sheets. Simulation results showed that the ore could be upgraded up to 64% Fe that formed the basis for a pilot plant campaign. A 5-in. hydrocyclone followed by a five-step spiral (5-ft diameter) was set up to process the ore in close circuit. The experimental results show that it is possible to raise the iron content up to 64.17% at a solid recovery of 37.38 with simultaneous decrease in the alumina content down to 1.17%. (C) 2001 Elsevier Science B.V. All rights reserved.