Dilution And Loss Control Of Pillar Stopes Mining Using Deep Hole Blasting

According to the site practice that deep hole blasting is adopted to extract ore of pillar stopes in FanKou Lead-Zinc mine, tightly combined with the research task-detection, obtain of3D boundary, and control of dilution and loss in deep hole blasting mining. the paper has comprehensively employed site detection, laboratory experiments and theoretical methods. that is, utilizing CMS, explicit dynamic analysis software LS-DYNA and3D mining software surpac, research on how to best control dilution and loss in pillar stopes mining was conducted. The study involves:(1)revealing the mechanical characteristics and damage mechanism of side backfill body in pillar stopes;(2)determining the reasonable strength ratio of backfill body suitable for practice; and (3) controlling the dilution and loss rate by backfill body strength control. Meanwhile, employing explicit dynamic analysis software LS-DYNA, side loading structure and side spacing with the minimum dilution and loss were optimized, thus, making it possible to control dilution and loss in terms of blasting control. Lastly, the feasibility of dilution and loss is proved by conducting site experiments, the main contents and results are listed as follows:(1)By performing indoor mechanical characteristics experiments such as uniaxial tension, compresion, shear with different ratio(ie.1:4,1:5,1:6),physical mechanical behavior parameters and failure characteristics of the three kinds of backfill body were obtained.(2)Established damage mechanics constitutional model of classified tailings cemented backfill body of FanKou Lead-Zinc mine by making theory analysis. Reasonable strength curves of classified tailings cemented backfill body in different mining depths were gained. The ratio scheme of classified tailings cemented backfill body under different mining depths was also gained.(3)Utilizing Explicit dynamic analysis software LS-DYNA, numerical simulation optimization to loading structure of side holes, spacing of sides and both ends of pillar stopes were made. On this basis, concluding that side spacing in sides and both ends under the best boundary blasting result are1.6m and1.2m,respectively;and the reasonable interval rate of loading structure is0.588.deep research on dilution and loss control of pillar stopes in view of complex boundary control in deep hole blasting.(4)Taking number Sh-400mS12-13#pillar stope as an example, research on application of dilution and loss control of pillar stope was conducted, and a comparison of dilution and loss index between the actual and the test one was made. It is shown through the result that the dilution rate and loss rate decreases4.90%and6.06%,respectively.which verifies the feasibility of dilution and loss control pillar stopes.The study improves the recovery rate of resources, boosts the efficiency of mining, and produces a larger economic benefit for the mine, which is of great engineering value.