Experimental research on the expectation body theory and optimization of the rate of advance during ore breaking in side drawing

Studies on the shape of an isolated extraction zone are the basis for investigating the flow laws of caved ore and rock and optimizing a stope's structural parameters. Based on the method of labeled markers, the shape of an isolated extraction zone and its changing law under both infinite and semi-infinite boundary conditions were analyzed, and the reliability and suitability of the ex-pectation body theory were validated through bottom and side drawing tests. On this basis, research on the rate of advance during ore breaking in side drawing was performed at the structural parameter of 18 m×20 m. The results show that the actual shape of the isola-ted extraction zone is not a standard ellipsoid, but more similar to the expectation body. Under both infinite and semi-infinite boundary conditions, the mass drawn has a power function relation with the height of the isolated extraction zone and has an exponential function relation with the radius of the isolated extraction zone. It is suggested that the non-dilution drawing mode and the 4.6-m rate of ad-vance during ore breaking should be preferentially used at the structural parameter of 18 m×20 m.