APPLICATION OF THE CONSTRUCTION WASTE AS A REDUCING AGENT IN THE SOLUBILITY OF IRON TAILING METALS

Abstract

Iron ore tailings has acid pH and high content of metals, such as iron, aluminum and manganese. Regarding the environment, these metals poses a risk of contaminating the soil and underground water. Yet, construction residues usually have high pH and because of this, they can be used to neutralize soil acidity and to reduce metal availability in mining tailing piles. The objective of this study was to evaluate the aplicabilith of CW to promote neutralization of the acidity in iron ore tailings aiming at decreasing the solubility and mobilith of metal found in them. Thus, a sample of construction waste was collected and characterized which was later incorporated at different doses into a sample of iron mining tailing collected in the Iron Quadrangle (Minas Gerais – Brazil). The construction waste raised the pH of the tailing sample from 5.58 to 8.22. Moreover, the incorporation of the waste incorporation decreased the manganese solubility in at least 80%. Despite the lack of national legislations and policies on the use of construction waste for this purpose, the results show that it is a promising technological alternative.