Study On Mining Methods For Gently Inclined Orebody With Medium Thickness In Guohua Mining Area Of Xinhua Phosphate

Abstract:Restricted by the attitude of orebody, rock drilling, ore drawing, stope support and other factors, it is always hard to exploit the gently inclined orebody with medium thickness safety, efficiently and economically. In order to solve the technical problems existing in Guohua mining area of Xinhua phosphate, this paper conduct a corresponding research on basic rock mechanics properties and mining methods&technology. The main contents are as follow:(1) Typical rock samples including roof and floor of orebed are carried back into laboratory rooms and processed into standard specimen. Basic physical and mechanics parameters of these samples are tested and got, so do the mechanical parameters of rock mass by discounting. Then the quality of engineering rock mass is classified using the discrimination model of quantification theory II on the basis of joint fracture survey and condidering the influence of blast vibration, exposed area and loosening zone of surrounding rock.(2) Refering to the experience of similar orebodies exploitation in our country&abroad and taking the specific condition of Guohua minging area into consideration,5original mining methods are designed. Then the operation procedure such as drilling, blasting, ventilation, stope support, ore drawing and backfilling of each method is described detailedly.(3) The fuzzy mathematics and analytic hierarchy process theory are used to select the best one among those5methods. Several indicators on technology, economic and safety are choosen to be discriminative indexes. Membership of each method is calculated and the best method is picked out due to the maximum membership grade principle.(4) To achieve mining safety, efficiently and economically, the stope structure parameters should be optimized. On the basis of engineering rock mass quality classification and minging methods selection,9different projects of stope structure parameters are proposed initially. The finite ANSYS software is adopted to simulate the excavation process under different projects. According to the analysis of the simulation results, the most suitable stope structure parameters are obtained. It turns out that both the width of room stope and pillar stope is10m.(5) The choosen mining method with the most optimal stope shructure parameters is applied for an industrial test. According to statistics, the production capacity of the text stope is460t/d, the ore loss rate is5%and3%for ore dilution rate. The results suggest that the choosen method which is safe, efficient and economic material benefit can meet the owners’demands well.