Abstract
Iron is the fourth most abundant mineral in the earth’s crust, and it is the most needed raw material in the manufacturing of steel. The demand for steel for construction, manufacturing of machines, pipelines, electrical appliances, military equipment, etc. is ever increasing leading to the increased demand for iron ore. However, exploitation of iron ore is associated with several undesirable impacts on the environment. The mining method for extraction of iron ore is usually opencast, or open pit method since most of it occurs close to the surface of the earth. Moreover, iron ore deposits mostly occur in forest areas and hilly terrain. Thus, it has the potential to cause degradation of surface and ground water, flora, and fauna, aesthetic view of the natural landscapes, as well as the ambient air quality within the mining area and surrounding environs. The contamination of water quality is mainly due to surface runoff and leachates that are generated from the overburden and tailings produced during mining and successive processing activities. Since most mines use overburden to backfill mined out areas, ground water adulteration may also result from leaching activities. In the present study, the leaching behavior of the solid wastes from two iron ore mines, one in India (Asia) and another in Liberia (West Africa) was investigated. The leaching behaviors of overburdens, tailings, and blue-dusts samples have been established using two types of leaching solutions. Results from indexing and leaching tests carried out revealed high levels of Fe, Hg, As, Cu, Ni, Mn, Zn, Se, NO3, Residual Chlorine, Fluoride, Phenol, etc. at most sampling locations. The leaching behaviors were found to be variable to locations, parameters, and types of leaching solution, as this could damage the environment significantly with harmful contaminants if protective measures are not taken. The overall findings on a comparative scale showed that both mining districts are polluted due iron ore mining, but the Liberian mining district is the most polluted, which calls for proper scientific management of the solid wastes generated from mining activities.