Study On The Safety Assessment On Large Open-pit Iron Mine

China is being in the process of industrialization which are characteristic of developing and utilizing material energy. With the increase of mining intensity for mineral resources, the security situation of mines worsens. The probability and the severity of the mine accidents are getting worse and worse. The prevention of mine accidents in surface mining as well as underground mining is necessary and difficult.. Mine safety's key topics are to eliminate the potential accidents in surface mining, to control mine industrial accidents and to reduce the casualties and property damage. Therefore, to deepen and perfect the evaluating indicator system in the safety production of surface mining and the research of assessment method are imperative.The production process of surface mining has many hazard factors. The hazard factor analysis is the premise of the safety evaluation. According to the classification of risk factors and production process, the safety assessment system is divided into six evaluation units. Six safety evaluation indexes are identified based on the identification and analysis of the present situation at Sijiaying surface mine, which is applied the safety system engineering elementary knowledge. Pre-risk analysis is selected according to appraisal goal and request. The Preliminary Hazard Analysis, Safety Check List and Dangerous Degree analysis methods are selected applying to the single appraisal unit. Finally, fuzzy mathematic method is utilized for the overall system. These four evaluation methods have constituted the safety evaluation system of surface mine.The fuzzy subjection degrees are determined by seting up the fuzzy membership function, numerical value statistic and expert evaluation method. Combination of qualitative and quantitative method of Analytic Hierarchy Process (AHP) is applied to determine the weight of evaluation factors, which is comparatively reasonable to reflect each appraisal factor of important degree to the overall system safety present situation.Finally, the quality synthetic evaluation is carried out. The conclusion shows that mining production process of the mine is relatively on the safety level, which is elicited from the fuzzy comprehensive evaluation calculation by determining each appraisal factor degree of membership value and weight value, and the aspect of safety control still needs to further consummate and to enhance. These four methods are suitable for open pit mine safety evaluation by practice validation.