Abstract In order to evaluate the cavability of ore-rocks in block caving method,fuzzy mathematics and matter element analysis method were combined together. The cavability of ore-rocks was divided into five grades including none,poor,fair,good and perfect as the types of matters elements. The RQD,the saturated uniaxial compressive strength,the distance of joint,the hydraulic radius of first cut and the hydraulic feature values were taken as the indices of evaluation. Based on the principle of membership degree in fuzzy evaluation analysis,the membership degree of ore-rock index relative to different evaluation categories were calculated. A model of cavability of ore-rocks in terms of complex fuzzy matter element analysis was established;and a method of cavabiltiy description was presented. The cavability of ore-rocks in a copper-molybdenum mine at the Jiuding mountain was evaluated with the proposed method. The results indicate that:the cavability of altered hornfels is fair;the cavability of altered granite porphyry is good;and the cavability of dense granite porphyry is poor. The results of the evaluation agree well with results of ore lumpiness monitoring and avoided the problem of incompatibility of the evaluation with a single factor index.
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Received: 15 July 2013
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