Introduction

Upon evaluation of the long-term accident statistics, it is inferred that the mining sector carries the risk of accidents above average when compared to the other sectors (Azapagic, 2004). Because, mining sector includes many high-risk activities, revealing that some features such as environmental conditions with a significant presence of humidity, dust or falling rocks have an important influence on the number and severity of accidents or incidents (Sanmiquel et al., 2015). Maintaining of the mining processes uninterruptedly and safely is an important issue. For an acceptable level of risk in mines, it is crucial to specify all the accidents and incidents comprehensively and observe the causes of the undesired events carefully. In this way, the priority fields might be specified and the improvement plans might be constituted to minimize the risk in mines. One of the systematic methods for analyzing the cause of risks is the fault tree analysis with graphic expression by adopting a deductive method, in which a specific risk that is only qualitatively recognized from a proper primary system (Hyun et al., 2015). The main purpose of this study is to identify the accidents and incidents with their root causes in a mine and to perform a risk analysis of these undesired events. For the risk analysis, a detailed methodology which is proper for the purpose of the study is developed using fault tree analysis and fuzzy approach. The methodology also enables to use the expert judgments without historical data for the analysis. It has been successfully applied to underground loading and conveying processes of a chrome mine within the scope of the research. Chrome being an important natural component is situated in metal mines, and it is a solid raw material used in the industrial sectors. Even though chrome mining is less risky than coal mining, harsh and dangerous working conditions of underground mining obstruct the maintenance of the mine extraction processes continuously and safely. Regardless of the type of mine, mining accidents and incidents may occur very often especially during many activities carried out by labour-intensive processes. Many accidents and incidents that may occur are specified comprehensively by implementing the proposed methodology to the particular processes of a mine Then occurrence probabilities of the accidents and incidents are determined through the quantitative side of the analysis, and consequences of the events are assigned. After getting the values for main components of the risk analysis, risk evaluation for the all possible accidents and incidents is performed. Because of the insufficient statistical data for probabilities and consequences of the events, fuzzy approach that ensures to infer the needed information from the experts’ judgments is used. Fuzzy approach allows to use the experts’ linguistic expressions instead of statistical data for the analysis and reduces the uncertainties about the data. After the literature review about the concepts and methods in the study are given in Section 2, all the details about the proposed risk analysis methodology are presented in Section 3. The implementation of the methodology to the particular processes of an underground mine is stated in Section 4 while the conclusions of the study together with the recommendations are provided in Section 5. The highlights of the proposed methodology can be given as 1) specifying the possible accidents and incidents that may occur in a particular process using the effective method of the fault tree analysis, 2) consulting with the various experts to provide the accuracy of the study, 3) determining of the undesired events’ probabilities which are needed for risk analysis utilizing the root causes established using fault tree analysis, and 4) converting the experts’ qualitative expressions about both probabilities and the consequences of the events to the numerical values using the fuzzy approach.