Aspectos ambientais aplicáveis a uma pilha de disposição de estéril de minério de ferro

Abstract

It is known that the disposal of waste rock in piles is a complex issue and it must be assessed and evaluated on a case-by-case basis. Since it involves risk, it is evident that the disposal must be planned and there must be regular geotechnical monitoring. The present paper addresses the environmental aspects related to an iron ore waste rock pile, as to make them physically and biologically stable. The specific objective of the work is to describe the rehabilitation techniques and methodologies applicable to these piles. The results of this work indicate that, in order to design a waste rock pile, the economic, technical and environmental issues must be considered, as well as the guidance from NRM N. 19 and ABNT N. 13.209/2006 standard. When building the pile, for safety reasons, it is recommendable that an underground drainage be built and, in order to avoid silting of the water bodies downstream from the pile, a settling pond must be built. During operations, it is suggested that the pile be expanded from bottom up, so that it is possible to evaluate its geotechnical characteristics and as a means to secure greater control for the subsequent layers of the pile. Another conclusion of the work is that, during the operational phase, the raising of the pile must be concurrent with the rehabilitation works, which is in accordance with the guidance from Sanchez et al. (2013) and that the rehabilitation done progressively results in more information and technical knowledge that will be used in the Environmental Plan for Mine Closure (PAFEM).