Study On The Waterproof And Drainage System In Deep Mining Of Xiao Longtan Open-pit Mine

Xiaolongtan Open-pit locates in Yunnan province, a tropical humid climate. It has clear dry and rainy seasons, always raining with large amount of rainfall and rainstorm. With the diversion of nan pan river flowing through Xiaolongtan mine district, existing drainage system of is no longer available for mining production; With mining depth increasing in Xiaolongtan open-pit, the drainage amount and drainage height difference increases. The existing drainage system has been unable to be applied for Xiaolongtan deep open-pit mining. The arrangement of drainage system plays a very important role on production safety in the Open-pit, therefore, a more suitable waterproofing and drainage system needs to be designed in order to in line with the deep open-pit mining.The hydrogeology within the scope of Xiaolongtan deep open-pit, the maximum daily rainfall over previous years,average annual rainfall and other data are comprehensively analyzed in this paper. Based on designed rainstorm frequency, water inflow is calculated respectively under the condition of different durations and different mining depths as the foundation of drainage system research in the surface mine.A major change on drain point of the original waterproofing system of Xiaolongtan and Buzhaoba surface mine has taken place in the north-south direction as Nanpan river is being diverted. Two feasible options are proposed on whether to change the Jiangbei flood control ditch system, the best solution, not to change the Jiangbei flood control ditch system, is obtained through the comparisons of implementation costs of two feasible options. The open-pit mine stope drainage difficulty increases as the drainage amount and drainage height difference increases with increasing depth of the open pit mining. The enumeration method and mathematical modeling are used so that the conclusion that the drainage cost when an end sump is designed in stope is the lowest and the end sump is arranged on + 740 m level is optimal open-pit drainage system are obtained. The transference of pump house and the arrangement of the open-pit bottom technology are studied.Due to depleted resource exploitation and other reasons, there will be an increasing trend that open pit mining depth increases, Xiaolongtan is one of the typical open-pits. The study of Waterproofing and drainage system in this paper, has a certain sense of reality and reference for the arrangement of Waterproofing and drainage system when the mining depth increases in other surface mine of our country.