| The occurrence condition of Jianshan Iron Mine is extremely complex. Containing a number of waste intercalated layers, the mine belongs to a inclined multi-belt mine, which is interbedded with many intercalated layer. The mine uses sublevel caving without sill pillars method. With the application of sublevel caving without sill pillars method, the ore loss and dilution control are difficult in the process of mining pit wallconnected ore body, it’s still lack of research for the conditions similar to Jianshan Iron Mine currently, which contains many intercalated layers.Taking reduce ore loss and dilution rate of pit wallconnected ore body of Jianshan Iron Mine for purposes, the paper has analyzed the causes of ore loss and dilution in Jianshan Iron Mine based on the actual exploitation, while using indoor physical simulation experiment and theoretical analysis. The study started from the following aspects:Analyze the granule moving law of blasted ore and rock, and plot the drawn-body shape for providing the basis for mining parameter optimization. Optimize drawing pace according to the granular flow parameters. Improve the existing ore way. Study the effect of waste intercalated layer on the ore drawing process, and propose effective programs to reduce loss and dilution caused by stone layer.The flow parameters measured by vertical solid wall drawing experiment list as follows:α=1.833;β=0.188;α1=1.512;β1=0.224, then determine the drawn-body shape according to the random medium theory. According to the drawn-body shape and flow parameters, taken18m as the current mining approach spacing is reasonable, but the drawing pace should range from5.3-6.75m, while the independent advance of Ore Breaking is3.5-4.5m. A multi-segmented ore experiments were conducted, the results showed that low dilution ore drawing way was better than the existing cut-off grade ore drawing way, and the cut-off grade of low dilution ore drawing was23%; and the best ore step close to4m, but the specific value needs to be verified by field tests. Flow parameters of blasted ore and rock layer were studied in indoor physical simulation experiment, the results showed the relationship between release amount of rock layer and drawn-body, and the impact on more than one segments of ore loss and dilution. At last, rock layer eliminated methods of Jianshan mine were studied based on the previous conclusion, put forward recommends to optimize mine management and eliminating intercalated layer by Cut-off Grade and controlling release ore.There are some innovations in the paper:Combine physical simulation experiment,3DMINE, Origin and theoretical analysis for experimental date, which provides a new method for study of flow parameters. Analyze the intercalated layers on the impact of ore law, and explore ways of intercalating layers based on the flow and mixed low of rock in ore particles. The studies made help to ore loss and dilution problems in multi-rock layer ore body of Jianshan Iron Mine, and provided a reference for similar geological mine. |
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