Experimental Study On Effects Of Sidewall Based On The Theory Of Ore Drawing With No-dilution

This dissertation designs a series of experiments about the effects rocksidewall, based on the theory of ore drawing with low dilution. It explores theore flowing law for the caved ore, it also probes the drawn-out body of ore atdifferent angles of the lateral opening. It analyses the causes of the adherentresidues, it also analyses the influence of the drawing step on the ore recoveringresults for the case of ore drawing with low dilution. At the same time, itprovides data for the following stereoscopic physical model experiment andnumerical simulation study.With the method of placing the indexed granules, we get the drawn-outbodies of ore for both the cases of55°and30°of the lateral opening angles.Through analyzing lengthways profiles of the drawn-out bodies in the directionsfor the cases both along and perpendicular to the axis of the tunnel, it shows thatthe drawn-out body of ore is approximately anisometric ellipsoid. Then, bycomparing the shapes of drawn-out bodies with the same height for the twoangles of the lateral opening, we get that the axial length of drawn-out body inthe perpendicular direction to the tunnel is larger when the lateral opening angleis smaller. And we also get the caved ore flowing law based on analyzingexperimental data when the lateral opening angle is55°.The influence the side-wall on the flowability of ore plays a critical role inthe process of forming the adherent residues. And the distance from the frontrock to the draw-hole is one of the factors that forms the adherent residues. Theshape and size of adherent residues relate to the width of drawing step andcut-off grade.The front rock reaches the draw-hole with top rock at the same time whenthe width of drawing step is5m. To judge from the amount of pure orerecovered, we can get that the optimal width of drawing step is5m from boththeoretical derivation and experimental results with the ore drawing with lowdilution in Shachang iron mine. To judge from the recovery ratio of ore, we canget the same conclusion.To analyze the recovery ratio and mixed rate of rock gotten from the experiments with the cut-off grade or low dilution, when width of drawing step is4m, we can get that the recovery ratios of two ore drawing modes are almostsimilar. At the same time, the mixed rate of rock gotten from the experimentswith the cut-off grade ore drawing mode is larger than the other one. Theadherent residues that arise from the previous step can be fully recovered in thenext drawing step.