A Fuzzy-Based Methodology to Determine the Environmental Factors Affecting Pre-Mature Mine Closure:An Approach to Sustainable Mining

Mine closure is regarded as the forth and the last phase of an open-pit mine planning and design. A mine will be closed when its ore reserves are totally exhausted but in some cases mines are closed due to various factors prior to the estimated reserve has been fully extracted. Among pre-mature mine closure agents, environmental factors play a major role in closure process. An appropriate investigation on environmental factors, followed by a successful mine closure plan, can result in reducing the adverse impacts of mining operations providing environmentally sustainable development. The aim of this study is to select and prioritize the environmental factors affecting pre-mature closure of an open-pit mine. With this respect, Angouran lead and zinc open-pit mine is considered as a case study. It is crucial to take into account the essential environmental criteria such as acid mine drainage, alkalinity, land or water pollution, etc.; hence, the issue is a Multi-Criteria Decision Making (MCDM) problem. This paper presents an evaluation model based on Fuzzy Analytic Hierarchy Process (Fuzzy AHP) approach, one of the most effective MCDM methods, to choose the environmental factors affecting pre-mature closure of Angouran mine. The suggested method applied to the mine and the most effective factors have been ranked and selected as pollution due to heavy metals, the presence of pyrite in the tailings and waste dumps, and sediment of chemicals with scores of 0.22, 0.21 and 0.15, respectively.