Kajian Teknis Mine Dewatering pada Tambang Terbuka PT. Putra Muba Coal Kabupaten Musi Banyuasin Provinsi Sumatera Selatan

Abstrak

The water discharge that enters the mine comes from runoff water discharge, rainwater discharge and groundwater debit. The water discharge will disrupt mining activities if not handled. The purpose of the research conducted is to calculate the water discharge entering the mining area and examine the dimensions of the open channels and settling ponds to match the water discharge entering the mine. Rainfall data obtained from the company will be used to calculate rainfall intensity using the mononobe formula. Calculation of rainfall intensity can determine the discharge of water in the sump. The calculation results show that runoff water discharge for each catchment area is CA I 0.0000116 m3/second, CA II is 0.000012 m3/second, CA III is 0.0000119 m3/second and rainwater discharge is 0.0015 m3/sec. The total discharge is influenced by the catchment area, the duration of the rain, the intensity of the rainfall and the planned rainfall for the 5-year return period. Based on the calculation of the discharge of water entering the mine, the dimensions of the open channel are the length of the side of the open channel 0.28 m, the width of the bottom of the open channel is 0.24 m, the width of the top of the open channel is 1.73 m, the depth of the channel is 0.24 m, the depth of the flow 0.21 m, guard height 0.031 m, channel wall slope of 60áµ’ and water surface width of 0.48 m, for the channel leading to the settling pond. The dimensions of the settling pond are zig-zag with 4 compartment zones with a depth of 4 m each, with a pool area of 445 m2, with a pool length of 15 m and a width of 30 m.