Unlocking the benefits of using recycled wastes in geotechnical tailings treatment: A sustainable approach

Purpose. This paper aims to establish a robust soil treatment plan designed to enhance the geotechnical engineering properties of tailings. The study evaluates the efficacy of various soil additives, including both traditional and non-traditional types, in reinforcing tailings dam materials. Methods. A comprehensive experimental program was conducted, where polymeric resin and a combination of recycled gypsum (B), cement kiln dust (CKD), and ordinary cement (OC) were added to tailings in a controlled laboratory setting. The assessment methodology included unconfined compressive strength (UCS) tests to determine the optimal treatment percentage, Oedometer tests to evaluate stiffness and consolidation properties, and direct shear strength tests to assess the material’s response to shearing. Findings. The study provides valuable insights into the performance of the CKD:B compound, revealing a critical OC percentage that must be maintained to prevent sample dissolution in water due to anhydrate presence. The tailings treated exhibit improved mechanical properties, contributing essential data that can support numerical modeling for assessing the stability of tailings dams. Originality. This research offers novel data on tailings treatment, particularly regarding the combination of CKD and B with OC. The study’s findings advance understanding in the field by identifying the optimal conditions for enhancing tailings dam stability, which has not been extensively explored in previous literature. Practical implications. The results of this study contribute to improved tailings storage facility management and environmental best practices. By optimizing soil treatment strategies, the research supports more effective utilization of natural resources and enhances the safety and sustainability of tailings dam structures.