Effect of planetary ball milling on phase transformation of a silica-rich iron ore

The phase transformation of a silica-rich iron ore during planetary milling has been studied. A mixture of silica-rich low grade iron ore and iron powder (4.75 wt.%) was subjected to high energy ball milling and the resulting products were characterized at various milling times. The major constituents of the silica-rich iron ore are hematite (54.2%) and quartz (44.6%). Upon milling, these phases have undergone phase transformation to form fayalite (Fe2SiO4) as the major phase along with unreacted quartz as the minor phase. X-ray and Mِssbauer spectroscopy studies confirmed the formation of fayalite phase. It was observed that the optimal constitution of the product, in which fayalite is the major phase, could be attained within 15 h of milling.