Study On Mining Method And Stability Of Goaf Of Gently Inclined Medium Thick Orebody Residual Resources

Phosphate rock resource is an indispensable strategic resource and an important material basis for China’s economic development.There are many characteristics of phosphate ore in China,such as low occurrence grade and different mining methods of gently inclined medium thick ore body.In view of the occurrence characteristics and mining status of phosphate rock resources in China,many mining enterprises abandon the basic principle of"both rich and poor mining",and the phenomenon of"mining rich and abandoning poor","mining above and leaving below"and"mining below and leaving above"widely exist in the mining of multi-layer medium-thick ore bodies.This disordered mining method not only causes a huge waste of precious phosphate resources,but also leaves a large area of goaf untreated,which brings great hidden trouble to mine safety production.This paper relies on baokang Yao Zhihe Hong Phosphorus Chemical Co.,LTD.Baizhu mining area mining method research topic,The mining method and stability of the residual mining area in the Ⅱ ore section were studied.,through field tests and indoor numerical simulation,the method of combining the optimizing the Ⅱ ore section of residual mineral resources mining method,and completed the stope stability analysis.The main work and research results are as follows:（1）In view of the fact that the Ph₁ layer at the bottom of the Ⅱ ore section of Baizhu Mining area of Hongphosphate mine has been completely exploited by comprehensive mining method,and a large number of point pillars and mined-out areas are left,the paper designs the reserved door pillar horizontal shallow hole retention and synchronous filling mining method for the Ⅱ ore section of residual ore resources.（2）According to the influence degree of blasting mining on the stability of mining area,the field monitoring test of blasting vibration is carried out,and the Sadowski formula which conforms to the attenuation law of blasting vibration speed in underground mining area is fitted.Through in-depth analysis of blasting vibration data,the typical"rebound effect"of blasting widely existed in mining area during secondary mining of residual ore resources is revealed,indicating that blasting seismic wave reflection is easy to cause tensile fracture damage to point column and side wall.（3）Physical and mechanical parameters of rock were tested for ore sections Ⅱ and Ⅲ.Physical and mechanical parameters such as compressive strength,elastic modulus and Poisson’s ratio were obtained by sonic wave velocity test,point load test and uniaxial and triaxial compression test.Considering the engineering reduction of blasting disturbance effect comprehensively,the mechanical parameters of rock mass in Baizhu mining area are obtained,which provides a calculation basis for subsequent research.（4）Based on the reserved door pillar horizontal shallow hole retention and synchronous filling mining method,with the help of numerical simulation software,the numerical simulation studies of three different working conditions,namely,the mining of residual ore resources,the completion of ore handling in the mine room and the synchronous filling of goaf,are completed,the stope stability is analyzed,and the reliability of the mining method of residual ore resources is evaluated.The strategic position of phosphate mineral resources is increasing day by day.The research on mining technology of residual ore resources of gently inclined medium thick orebody is a subject with practical application significance.The research results of this paper can provide reference for mining residual ore resources of similar mines.