Estudo do comportamento de barreiras impermeáveis e detecção de vazamento para gestao de risco em bacia de rejeito de mineração

Abstract

Proper design and safe execution of impermeable barriers in tailings dams ensure the reliability of the use of various geosynthetics as reinforcement, containment and waterproofing materials in mining. And of this technical solution, it is bound to guarantee the maintenance of the parameters and properties inherent to each type of material used, which give them the necessary qualities and performance, throughout the period required by the geotechnical project. The Vanadium de Maracás S / A project is located in the municipality of Maracás / BA and will be built in three stages, with a final capacity forecast of the nonmagnetic repository of the vanadium ore No. 4 (BNM-04) of 1,047,532.57m³ of non-magnetic waste. In order to guarantee adequate sealing parameters in the bottom and slopes of this basin, a four-layer waterproofing system of geosynthetics was used, consisting of a nonwoven geotextile, and a double layer of HDPE geomembrane separated by a geodrene system ( georrede in HDPE). The objective of this research is to evaluate the geotechnical behavior of the BNM-04, through the analysis of the safety model adopted for leakage detection, physical and mechanical properties of the different reinforcement materials used in laboratory characterization tests and durability in the field, as well as the analysis of non-magnetic vanadium tailings characteristics. In spite of the fact that the physical and mechanical characterization of the different materials used in the work were carried out, we did not predefine the comparative analysis with the technical datasheets of the manufacturers to verify inconsistencies, but rather the understanding of the model as a safe and excellent performance system. The durability tests were not evaluated in this study, due to the long duration of the procedure. The non-magnetic vanadium reject was designated as a sandy silt with traces of dark gray clay.