Abstract:Aiming at the flap top problem caused by 17m high-sublevel of the non-pillar sublevel caving method in Sifang gold mine, a 12.5m low-sublevel scheme is proposed. Through the similar physical experiment of side ore drawing, combined with ellipsoid ore drawing theory and mathematical regression analysis, the moving boundary coefficient and the moving trace index which reflect the law of ore flow in Sifang gold mine are measured, when the height of sublevel is 12.5m, the length of axle a is 12.5m, b is 4.0m and c is 4.5m.On the basis of the above results, determined the drift interval is 14m according to draw body arrangement of big spacing, deduced the function of independent advance of ore breaking with ore-recovering rate and dilution ratio according to draw body is a forward lean flat missing ellipsoid, the model of ratio difference between the recovery and dilution is constructed, and the effect of ore recovery is evaluated by ratio difference between the recovery and dilution, the best independent advance of ore breaking is 3.1-3.3m. The results provide the basis for optimizing the structural parameters and avoiding the roof accident.