Physico-chemical properties of mill scale iron powders

Abstract

Powdered form of iron typically < 250 microns is phrased as iron powder. Commercial manufacturing of iron powder is majorly restricted to atomization, carbonyl, electrolytic and reduction routes. Powders from the later three techniques generally cater to special iron powders applicable to non-powder metallurgy segments such as food fortification, chemical reagents, water purification, etc. In this work, mill scale iron powders are synthesized by thermo-chemical reduction of mill scale, a steel industry by product, and their properties are analysed and compared with commercial iron powders such as carbonyl, electrolytic and reduced. Chemical and physical characterizations such as Optical Microscopy, Scanning Electron Microscopy and X-ray Diffraction of the powders are performed. Obtained results reveal that, mill scale iron powders MIP and MIP45 possess good product properties. Especially, MIP45 grade exhibited finer particle size of D50< 30 microns and BET surface area of 0.63 m2/g along with Fe (T) > 98%, true density-7.55 g/cc, apparent density 2.67–2.83 g/cc, packed bulk density of 3.44 g/cc and good flowability. This product of mill scale with highest apparent density and good surface area is expected to qualify to new segment of applications along with other commercial iron powders.