(3)Twelve years of experience of tailings dams phytostabilization. What have we learned?

摘要

The article presents the experiences gained by the authors over twelveyears and various alternatives to stabilize tailings by introducing plantspecies or phytostabilization in the closure and abandonment stage, wheredispersion of particulate matter and major wind erosion is generated. Theobjective was to mitigate the effects of the presence of harsh winds, whichmay affect slope stability of tailings dams and negatively impact theenvironment. The development of a bio soil improver, using a tailing damlocated at “Planta Matta” from the Empresa Nacional de Minería (ENAMI)in Copiapo as an experimental field. In these experiments carried out inthe early 90s with the Pontificia Universidad Catolica de Valparaíso (PUCV),creeping plant species and shrub type in the slope and the crest, and treetypes on crowning and the bucket of old dams were implanted. Themethodology includes the incorporation of free-living nematodes andmany bacterial species in the rhizosphere soil, which improves soildynamics and streamlines functionality on the slopes and bucket. Then, aworking group from the University of Santiago de Chile (USACH) wasjoined, and their work was focused on establishing a bank of plants andrhizosphere microorganisms tolerant to extreme conditions for a potentialphytotechnology use, allowing us to evaluate the effectiveness of this kindof technology for mining sites in the northern country. The results showan improvment in the copper removal from tailings, organic matter on thesludge and the original pH.This work contributes to the evaluation of the phytostabilization onfield experiences with natural conditions using a scale that allows doing acosting and feasibility assessment with real data, with low investment andoperating costs, providing us an option for rehabilitation and reclamationof sites operated by mining activities.