Application of Fuzzy AHP in Order to Risk Management of Pre-mature Mine Closure

A mine closure plan is implemented while mine’s deposit is totally exhausted. It is necessary to precisely identify and analyze these factors and their impacts on mine’s life. In this research, with the purpose of identifying and analyzing the factors affecting the premature closure of Chadermaloo Iron ore mine, a comprehensive risk closure model of Chadormalou mine was developed based on the Laurence’s closure risk model. With this respect, in order to assess the probabilities and consequences of broad and sub-issue closure risks, questionnaires have been provided and distributed through the seven experts in case study mine site and filled questionnaires based on experts’ judgment collected to obtain certain values of risks. In the next step, identification and ranking of the factors affecting the premature closure of surface mines was designed in a hierarchical structure in order to predict and take appropriate measures. The model at the level of criteria includes four main components consists of probability of occurrence, consequence, uncertainty of estimation and ability of the organization in responding to risk. The alternatives comprises risk factors in the social, political, economic, environmental, legal, technical, safety and health issues. Whole calculations were performed in accordance with Chang approach through Fuzzy Analytical Hierarchy Process (FAHP) to evaluate and rank relative and final weights of each criterion involved in premature closure risk assessment. The results of application of closure risk model to Chadormaloo mine demonstrated that the mine is classified as "moderate" from premature closure point of view. The closure probability of 30 percentage shows the mining activities are able to be continued. This implies more attention should be paid to eliminate or minimize the impacts of these issues within mine’s planning and design.