Experimental Research On Ore Drawing Method With Non-dilution Under Different Orebody Conditions

Due to the complex occurrence conditions of the metal deposits and differentphysics properties of ore and surrounding rock, nowadays, it has developed manymining methods. However, sublevel caving method has been used in manyunderground mining of the world's major iron ore for its merit of simple process,high mechanization degree, safety, high yield, easy management and so on. InChina, many iron mines also use this method. But since majority of mines usecut-off grade drawing mode to control ore drawing, it is inevitable that theseverely dilution of the ore become the weakness of this method. This paper hasperformed a series of experiments on how to achieve non-dilution ore drawing inShaChang iron mine based on sublevel caving method with non-dilution oredrawing theory. The detailed research contents and results are as follows:The experiment of vertical wall's ore drawing with non-dilution is performedin laboratory by using the physical model. In the model, there are seven sublevels,each with three tunnels. In every single tunnel, six ore drawing steps aredesigned. The experiment certificates that adherent residues are formed in theprogress of mining without dilution. This thesis preliminarily studies the role ofride residues, fringe residues and adherent residues in the progress of oredrawing with low dilution and the influence of three kinds of residues to differentsublevels and different steps in the same sublevel. The result proves that theprocedure of ore drawing with non-dilution is a system, and it's unwise to studythe interaction and mutual adjustment between steps and segments separately.Ride residues perform a leading role of adjustment in the process of ore drawing.The experiment of ore drawing with non-dilution of60degree inclined orebody is performed by using the physical model which has five sublevels, threetunnels. In every single tunnel has ten ore drawing steps. By drawing two60degree inclined lines on the two sides of the model, the experiment is used tostudy the ore drawing with low dilution for inclined ore body. It is difficult to useore drawing with low dilution in inclined ore body, because the inclined ore-rockcontact line is unfavorable for the growth of the ellipsoid. Through controllingthe amount of the ore drawing of the inclined steps to adjust the ore-rock contract line, this experiment will reduce the adverse impact of the inclined steps onnon-dilution ore drawing. The result shows that ore drawing with low dilution in60degree inclined ore body is possible.Through the analysis of experimental results and the problems encounteredduring the experiment after the two experiments, this paper proposedexperimental improvement program to improve the management of ore drawingmode.Comparison among the two groups of experimental results shows that oredrawing with non-dilution in ShaChang iron mine is possible for both the casesof the vertical ore body and60degree inclined ore body. The economic benefitsby using this method in ShaChang iron mine is considerate.