Utilization of Low Grade Coal for Direct Reduction of Mill Scale to Obtain Sponge Iron: Effect of Reduction Time and Particle Size

Demand of today is to optimize the available resources and reutilize the waste materials. Mill scale is waste cum byproduct obtained during hot rolling operation of steels.In Rajasthan there are hundreds of hot rolling mills producing tons of mill scale everyday and in Nagaur, Rajasthan there are huge reserves of low grade coal. In this paper an attempt has been made to utilize the low grade coal for direct reduction of mill scale in laboratory to obtain sponge iron .The paper comprises the study on effects of variation in particle size(60-100,170-200 and <325 ASTM sieve size) and time (30, 60, 90 minutes) on reduction behaviour of mill scale in a fixed reducing atmosphere (900 °C), taken lime (10% of weight of mill scale) as catalyst. Further reduced samples were characterized by using EDX, SEM (Scanning Electron Microscope) and XRD (X-Ray Diffraction). It has been identified that the maximum reduction of mill scale (81.64%) is found in the sample reduced for 90 minutes with particle size ranging between 60-100 (ASTM sieve size).