The Effect of Microwave Treatment on Dry Grinding Kinetics of Iron Ore

Abstract

The effect of microwave treatment on the grinding kinetics of an iron ore was assessed using mono-sized materials of −2.360 + 2.0 mm, −1.400 + 1.180 mm, −1.0 + 0.850 mm, and −0.355 + 0.300 mm as feed. Microwave-treated samples were kept in a multimode microwave oven with 1100 W input power. The grinding tests were conducted using a laboratory ball mill under identical conditions to allow a comparative analysis of the results. The specific rates of breakage (S_i) and cumulative breakage distribution function (B_i,j) values, as grinding breakage parameters, were determined for those size fractions of untreated and microwave-treated feeds. It was determined that breakage of iron ore followed a first-order behavior for fine feed sizes and deviated from first order for coarse feed size. The specific rate of breakage parameters of untreated iron ore was compared with microwave-treated iron ore under the same experimental conditions and it was found that microwave-treated materials break faster than untreated in terms of the S_i and A values. Breakage parameters showed that treated materials produce more coarse material than untreated material in terms of the γ value of B_i,j.

Keywords:

• grinding
• iron ores
• microwave processing

ACKNOWLEDGMENTS

The authors would like to thank the University of Tarbiat Modares and Iran Central Iron Ore Company for funding this research work.