Study On The Migration Law Of Mineral And Rock In Side Ore Drawing By Caving Mining Method

In Non-pillar sublevel caving method,ore caving and ore discharge is done under the loose overburden rock.The problems of large ore loss and dilution and poor recovery effect are very prominent.Therefore,the flow characteristics of the ore rock in the end drawing and the law of its release are still the important content of current research.On the basis of in-depth analysis of the occurrence form and mixing process of waste rock at the top,front and side parts,a physical simulation experiment of in-situ replacement method was designed to conduct quantitative research on the mixing of waste rock at different parts.Based on the response surface method,the influence of the interaction among the segmental height,the path spacing and the collapse step on the mixing of waste rock was studied,and the mixing law of waste rock at different parts under different structural parameters was analyzed.Based on the discrete element method,the end drawing model was established,and the multi-scale statistical law in the drawing process was studied.The following results have been achieved:(1)Based on the ellipsoid theory,the general calculation formula of the volume of waste rock discharge in each part of the end ore-drawing was derived to obtain the ore recovery rate and the mixing rate of waste rock in each part,which provided theoretical support for the study of the mixing law of waste rock in each part.(2)Mapped the front,sides and the top of the waste rock with the curve relationship between the recovery rate-the mixed rock rate,got the different parts were mixed with waste rock sequence and the amount of mixed with different time,on the study of the different parts were mixed with waste rock from qualitative analysis to quantitative analysis,for the actual mining stope design,offer some guidance of mine production.(3)The response surface model of ore mixture rate is established,the response surface is nonlinear,the segmental height,path spacing,collapse step and interaction relation all have significant influence on the ore mixture rate,the correlation coefficient of regression model fitting is close to 1,and the optimal structure parameter is obtained by using the satisfaction function.(4)Changing the structural parameters can change the mixing process of waste rock in various parts,which can reduce ore dilution to the greatest extent,reduce the mixing opportunity of ore and rock,and achieve a better mining effect.(5)Based on the discrete element theory,the numerical model of ore-drawing was constructed to analyze the morphological change law of the ore-drawing body and the stress distribution during different ore-drawing processes in the ore-drawing field;The distribution law of coordination number and contact force in the process of ore drawing is studied in microcosmic Angle,and the structure and strength of force chain in ore drawing are further discussed in mesoscopic Angle.The understanding of the ore drawing law at the side of the caving method is strengthened.