On The Level Of Layered Waste Rock Fill Method, Applied Research, In Thick Ore Body Tilt In The Eastern Mountains Of Iron Ore

According to the exploitation effect of many inclined medium thick ore bodies at home and abroad, the overall characteristics are high rate of ore loss and dilution,inefficient,and high accident rate. Ore in the stope can not slipped by gravity, and it is difficult for the efficient machinery to enter the stope,either to maintain the roof,so the exploitation of inclined-medium thick orebody has always been a problem of mining engineering..Therefore, how to exploit the inclined medium thick orebody safely and efficiently, which accounts for about 23% of the underground mining in China, is of great significance to mining industry.Dongdashan iron ore has a inclination of 41°and a thickness of 6m in average, with an immediate schist iron roof about 1～3m thick, which is unstable and easy to fall. Sublevel stoping method is used to exploit ores, with its recovery rate ranging from 49.25% to 55%, and dilution 33.37% to 29.92%. This paper studies Dongdashan iron ore mining methods and indicates the low recovery of sublevel mining is caused by the loss of ores at the bottom of the stope. After researching the advantages and disadvantages of different mining methods, the method of cutting and filling with waste rocks is proposed.Numerical simulation with FLAC 3D (Fast Lagrangian Analysis of Continua in 3 Dimensions) is used to optimize structural parameters. Six parameter programs are compared to study how layered span, length and face roof under control affect the stability of the stope. These parameters are as follows:the length of stope is 60m, the span is the thickness of the ore body, the height of face roof under control is 5m,and the layered height of the mining and filling is 2.5m. Eventually, this paper indicates the safe and most effective structural parameters and points out where the danger areas are.and its extraction method.It's also succeeds in industrial experiments. Its recovery ratio increases to 89.41%, and dilution decreases from 30%to 15.64%.,while the mining cost increases only 8.6% compared with the sublevel open stoping. Meanwhile, a large scale of waste rocks is used to backfill mined-out areas, which has important economic benefit and social consequences. The results of this research can be applied to similar mines.