Grinding wear behaviour of stepped austempered ductile Iron as media material during comminution of Iron ore in ball mills

Abstract

An attempt has been made to evaluate the suitability of austempered ductile iron (ADI) as media material for grinding iron ore in a ball mill. Spheroidal graphite (S.G) iron balls are austenitised at 900�C for 60 minutes and given stepped austempering treatment at 280�C for 30 minutes and 60 minutes followed by 380�C for 60 minutes in each case. These materials are characterised by measuring hardness, analysing X-ray diffraction (X-RD), studying microstructure using optical and scanning electron microscope (SEM). Grinding wear behaviour of these materials was assessed for wear loss in wet condition at different pH value of the mineral slurry and found that the wear rate of grinding media material decreases with increase in pH of the slurry. The wear resistance of ADI balls were compared with forged En31 steel balls and found that the stepped austempered ductile iron is superior to forged En31 steel balls. � 2010 American Institute of Physics.