Recycling blends of waste groundnut shells and high density polyethylene as reductants in the microwave production of iron nuggets from the Pudo iron ore

Abstract

Different ores of iron have responded differently when subjected to various technologies of iron ore reduction. The Pudo iron ore in the Upper West Region of Ghana is known to exist in two forms; a low grade iron (in the form of Fe2O3) which has desirable amounts of CaO and MgO and a high grade titaniferous-magnetiferous ore (Fe3O4). In this work, the low grade iron oxide was reduced by using a locally available biomass (Groundnut Shells, GNS) and its blends with High Density Polyethylene (HDPE) as reducing agent. The microwave technology was used for the reduction process. Composite pellets composed of the iron ore, reducing agents of different blends and flour (binder) were formed and subjected to a 2400 MW, 50 Hz microwave for firing. Each pellet was fired for forty minutes. The results of this study indicate that the GNS as reducing agent solely was able to reduce the ore to about 54 % in the reduction process. Blending of the biomass with HDPE led to an improvement in the percent reduction with maximum percent reduction of about 80 %. The reduction process was however accompanied with high undesirable amounts of slag and low amounts of metallic spheres of iron. The iron produced was highly carburised since temperatures below the melting point of iron were recorded during the reduction process (maximum of 1197 ºC). The residue produced in this study is mostly made up of titanium, silicon and other elements in smaller quantities