Characterization of sludge from the tailings with fly ash and red mud after the process of solidification/stabilization

Abstract

The paper presents the problem of waste sludge from mine tailing 'Sasa" contaminated with toxic metals, as well as the treatment of process solidification/stabilization. As a stabilizing agent fly ash and red mud were used. Fly ash and red mud represent a secondary industrial waste, and its application in the treatment immobilized two types of waste. Over the past few years, the term "green" concept of hazardous waste management has gained increasing importance, and refers to processes and activities that have a small or negligible impact on the environment. A modified sequential extraction was used to estimate potential metal mobility in untreated and treated mine tailings samples. The results of the sequential extraction procedure of the S/S mixture indicate that the metals in the mixtures are almost completely immobilized and do not pose a risk to the environment, especially in the red sludge mixture. The main objective of this paper is to characterize the treated samples using a scanning electron microscopy with elemental analysis (SEM-EDS) and X-ray diffraction (XRD). This analysis confirmed the formation of compact matrices and pozzolanic products. Obtained results indicated that red mud and fly ash effectively perform the immobilization of metals in the mine tailing.