Grey Decision-Making for Constructional Parameters of Non-Pillar Sublevel Caving in Zhangjiawa Iron Mine

Taking the conditions of the medium ore body of-250?m phase in Zhangjiawa Iron Mine as background,a simulating experiment was carried out with different constructional parameters for non-pillar sublevel caving.Introducing the grey decision-making theory in the optimization of constructional parameters,the problem to transform multi-object optimization including the rates of ore recovery,undiluted ore recovery and rock drop-in into a single-object optimization was successfully solved.According to the experimental results,it was found that such optimum constructional parameters as sublevel height,drift interval and drawing pace are 12.5?m,12?m and 4～5?m,respectively,for the non-pillar sublevel caving of the medium-250?m phase.The investigation provides not only a foundation on which the design of mining preparation is available but also a new approach to the optimization of mining engineering.