Exhumation of stacked geotextile tubes filled with gold mines tailings

Abstract

Geotextile tubes are usually made of at least one layer of high-strength geotextile, functioning as a dewatering containment. Recent studies have shown the possibility to use this technology as an alternative to traditional mining tailings disposal methods. The geotextile allows fast dewatering and consolidation of the filling material; the water resulting from drainage can be reused in the mining process. This paper aims to verify the conditions of a stacked geotextile tube structure filled with gold ore tailings two years after being hydraulically filled in the field. The exhumation project designed to collect tailings and geotextile samples is presented. After being collected, the tailings’ samples were submitted to laboratory tests to evaluate the geotechnical properties of the tailings. The parameters obtained by the settlement tests are presented, as well as the influence of the stress level on the permeability of the material confined in the tube. Samples were collected to evaluate geotextile’s resistance properties after use - and disturbed and undisturbed samples from the filling material. The results indicate good dewatering performance of the tube if compared to traditional tailings disposal methods, evaluated through tailings geotechnical parameters; it was also noted increased values on tailings’ resistance parameters.