Studies into the nature of the Pudo iron ore and Its response to reduction using end-of-life tyres

Abstract

In this work the nature of the Pudo iron ores in the Northern Region of Ghana and the potential for producing premium grade iron nuggets from the ores is investigated using carbonaceous materials generated from end-of-life rubber tyre (ELT) as reductant. Physical analyses such as, specific gravity, particle size distribution and Bond Work and Abrasion indices were performed on the as-received samples of the Pudo Titaniferous Magnetite ore. Pulverised samples of the ores (magnetite and non-magnetic) were then characterised by X-ray fluorescence (XRF) analysis, and Scanning Electron Microscopy-Energy Dispersive Spectroscopy, (SEM/EDS) analyses. The results from the XRF and SEM analyses of the representative sample showed that the Pudo non-magnetic iron ore is of a low-grade hematite with an average Fe content of about 10.17 wt%, but an excellent fluxing material since it has high amounts of magnesia and calcium oxide, with high amount of gangue material (SiO2 + Al2O3) and no deleterious elements (sulphur and phosphorus). The Pudo magnetite ore is a moderately high grade ore with an average grade of 80.918 wt% Fe2O3 (56.59 wt% Fe), with the presence of TiO2 (10.140 wt %) and (0.018 wt%) sulphur. Values obtained from the abrasion and Bond Ball Mill Work Indices test showed that the Pudo Titaniferous magnetite ore is a very hard ore with values of 0.254 and 23.535 kWh/t, respectively. Carbonaceous materials were generated from ELT by pulverising charred crumbs of ELT in a laboratory ball mill to -106 µm. Proximate analysis conducted on ELT agrees with work done by previous researchers. Reduction studies were conducted on composite pellets of mixed variants of the iron ore containing charred ELT in a domestic microwave oven and the extent of reduction was calculated after microwave irradiation for 40 minutes. It was observed that premium grade metallic iron can be produced from appropriate blends of the Pudo iron ores using ELT as reductant, with a measured extent of reduction up to 103.8%