Towards sustainable mine closure and reclamation through strategic tailing disposal sites evaluation: A causality-based Dempster-Shafer framework

Tailings, the byproducts of mineral processing, present substantial environmental risks, both physically and chemically, including potential irreversible ecological damage if not properly managed. This study introduces a hybrid decision-support framework for evaluating strategic tailings disposal sites by integrating sustainability, mine closure planning, and risk-informed governance. A key innovation is the direct linkage between tailings siting and mine reclamation strategies, offering new insights for sustainable mining. The framework combines fuzzy cognitive mapping (FCM) for causal analysis with Dempster-Shafer Theory (DST)-based evidential reasoning to address uncertainty and expert judgment variability. Twelve site selection criteria were identified from literature and expert consultation, with interdependencies modeled using a hybrid nonlinear Hebbian learning–differential evolution (NHL-DE) FCM algorithm. The approach was applied to the Zarshouran Gold Mine in Iran to support decisions in line with global tailings governance frameworks such as the Global Industry Standard on Tailings Management (GISTM). DST was used to compute belief degrees for alternative sites, reflecting environmental, technical, and socio-economic factors. Results revealed that “Socioeconomic impact on downstream communities” and “Engineering challenges” were the most influential criteria (both with normalized causal weights of 0.110). The most favorable site, located near the processing plant, achieved an 84.6 % belief degree at the “Good-Excellent” level, followed by a site near the pit (82.4 %). By streamlining methodology and emphasizing site-specific insights, the framework offers a robust tool for prioritizing tailings sites under uncertainty, aligning technical evaluations with ESG principles and mine closure objectives.