Análise geotécnica e ambiental do sistema de empilhamento de rejeito minerário considerando a Lei 14.066/2020

Abstract

The growth in rhythm accelerated growth in the mining sector has generated the excessive production of tailings in piles and dams’ reservoirs, leading to a Strong concern in the socio-environmental scope. The present research deals with the case study of a tailings pile located in the state of Minas Gerais/Brazil in the process of decommissioning because it is in the final stage of its useful life with a high potential to cause harm to Society and the environment, which came to be classified as a Tailing Dam with the update of the National Dam Safety Policy - Law 14.066/2020. The objective was to evaluate the geotechnical and environmental characteristics and the regularization of the environmental liabilities generated in the process of de-characterization and decommissioning of an iron ore tailings pile (PDR), located in the Iron Quadrangle, considering the scenarios preceding and after the update of the Policy National Dam Safety - Law 14.066/2020. For this, scientific literature, technical documents from environmental agencies, environmental indicators, geotechnical stability parameters, technical visits to the study site, and a questionnaire applied to various professionals, from researchers to construction workers, were selected. As a result, it was not only verified that the construction method of the pile was the apex for the Law to classify it as a tailings dam, but also the need to: assign to the mining companies the responsibility of carrying out more detailed studies of the main geotechnical and environmental parameters, such as material properties, stability analysis, risk category, and associated potential damage, to start the decommissioning process as it is an environmental liability with high socio-environmental risks; and, attributing to the supervisory bodies, the responsibility to inspect in a more accentuated way.