Assessment of recycling potential of the oily mill scale in the steelmaking industry

Abstract

The purpose of our paper is to assess the recycling potential of the oily mill scale, from Crişeni landfill (Salaj County, Romania). We present the experimental procedures for determining chemical composition and for the granulometric distribution, of the oily mill scales samples taken from Crişeni landfill. According to the data obtained, in the chemical composition of the oily mill scale we identified the following elements: Ca, K, Ba, As, Cu, Cs, Fetotal, Mn, Mo, Ni, Se, Sb, Sn, Te, Zn, Sr, Rb, V, Cd, Co, Hg, Pb and Crtotal. The metallic iron, from the mill scale composition, can be reused as a source of raw material in the steelmaking process (from which it originates) or in other metallurgical processes. The mill scale sample has significant concentrations of alloying elements, such as: nickel, chromium, manganese, molybdenum and vanadium. These chemical elements can be reused in the production of alloyed or high alloy steels in the form of ferro-alloys. The results of the granulometric distribution, shows that particles with diameters ranging from 0.005 <d <0.05 predominates in the composition of the mill scale. Internal recycling of the mill scale, from Crişeni landfill, leads to a sustainable steel manufacturing.