Analysis of the economic feasibility of a mining project due to the presence of natural underground cavities.

Abstract

The legislation for the protection and conservation of caves is recent in Brazil. In 2008, the Decree 6.640 was enacted and in 2009, the Normative Instruction Nº 2 by the Brazilian Environment Ministry (MMA, Portuguese acronyms) was published. Mining operations cause a significant impact on the caves when they are present in or next to the mineral body. The impacts include the suppression of cavities and impacts on physical and bio-speleological stability of the caves. On the other hand, the actual legislation causes a significant impact on the mineable reserves when cavities are pres¬ent. This article aims to assess the impact of the natural cavities on the feasibility of a mining project, based on the federal legislation, as well as to propose alternatives to combine mining activity with cave protection. For this research, three scenarios of open pit for a hypothetical ore body were considered for the assessments. This paper presents the results achieved for the three and comments on the necessity of researches to conciliate the conservation of the natural underground cavities with the mining activities.