Chemical Characterization and Leaching Kinetics of Metals From Iron Ores

Abstract

The impact of mineral deposit on their host agricultural soil, available water bodies and near atmospheric environment is of great concern. In this study, mineralogical characterization and leaching kinetics of metals from iron ores in Kogi States, were reported. Physicochemical parameters namely; electrical density, pH, bulk density and moisture content were also investigated. The SEM image of the iron ore appear compact with irregular shape. XRF analysis showed that, iron ore consist of 63.44 % Fe as major element, with the oxide composition of 90.71%. The XRD analysis of iron ore unveiled the presence of magnetite (88 %), hematite (9 %) and quartz (3 %) as associated mineral. Low concentration of iron (0.77-1.70 ppm) was observed to be leached from iron ore in the acidic medium, 0.35-1.10 ppm from basic medium and 0.32-0.88 ppm in the aqueous medium, The Shrinking core, Product-layer diffusion and leaching, controlled by diffusion were the three equations used to model the leaching parameters. The leaching experimental data of iron ore fit best into the diffusion- controlled model, with R2 = 0.94 for the acidic medium Hence, the rate determining step. The analysis shows good fit for the other kinetic models. Overall, result proved that, the environment around mining sites is chiefly contaminated by the metals leached from the ore (mineral) deposits. Hence, the need to monitor the pollution indices, the role of leaching, pollutant fate (transport and reaction) and the subsequent distribution of metals to neighboring environment.