Influence Of Open Turn Underground Open-pit Filling On Underground Mining In A Lead-zinc

In the process of transferring from open pit to underground mine,making full use of existing open pit tailings can not only reduce the expansion of tailings reservoir,making full use of existing open pit tailings can not only reduce the land occupation of tailings reservoir,save the construction investment and maintenance cost of tailings pond,reduce the environmental pollution caused by tailings,but also fill the open pit goaf,solve the disposal problem of abandoned open pit,and create land reclamation and vegetation restoration.At the same time,the open-pit reclamation will greatly reduce the surface water seepage through the open-pit to the underground,reduce the underground drainage costs and flood control pressure.It not only has important practical significance for the realization of green mining and digital mine construction at present,but also has important environmental protection significance for the mine ecology and environmental protection.Through this study,the main conclusions are as follows:(1)By collecting and studying the previous geological data and design documents as well as related research documents,and on the basis of full understanding of the location,size and shape of the goaf.The integral stability of goaf and open-pit slope formed by the first and second mining projects of ore body is analyzed by finite difference numerical simulation,the distribution of displacement field and stress field in goaf after mining is obtained by numerical simulation results.Based on the numerical simulation results,the technical scheme of tailings filling open pit is presented.(2)Based on the analysis of the characteristics of tailings,combined with the previous engineering data and related research documents,the proper proportion of cemented filling for tailings is selected,and the filling scheme of goaf and opencast pit was put forward according to its research.(3)The countermeasures and suggestions for the treatment of goaf are put forward,and the technical safeguard measures of filling are put forward.The open pit after filling has no influence on the third stage of underground mining,and the whole mine is still in a stable state in the third stage of mining.This paper closely combined with the mine production practice,through this project research,realizes the open pit stope safety,highly efficient discharge tailings,not only achieves the purpose of controlling the open pit environment and safety hidden danger,but also solves the mine mud fine sand discharge problem.Greatly reduce surface water seepage through open pit to downhole to reduce drainage costs,reduce flood control pressure.Finally,the open pit is eliminated and reclamation is realized.The filling of open pit has no influence on underground mining,and the underground goaf is in a stable state,which can realize safe and efficient mining in mine.