DESIGN OF MINE DRAINAGE SYSTEM IN THE POST-MINING SYSTEM (CASE STUDY OF THE SOUTHWEST AREA OF THE BINUNGAN MINE OPERATION SITE 2 BLOCK 8 PT BERAU COAL, EAST KALIMANTAN)

• Main Author: Raihan Aziz, Muhammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69317
• Institution: Institut Teknologi Bandung

Binungan Mine Operation (BMO) Site 2 Block 8 is one of PT Berau Coal’s mining sites which is planned to end its production operation period and will enter the post-mining period in 2025. In the current post-mining planning, one of the options for a post-mining water management scheme at Site BMO 2 Block 8 is to divide 3 managements areas based on 3 main catchment areas and based on a water quality problem handling plan. The purpose of this study is to make recommendations for a post-mining drainage system in the southwest catchment area of Site BMO 2 Block 8. Based on the analysis of hydrological conditions and analysis of the final design of the mine, the recommendations of mine drainage for the upstream part are open channels of a triangular shape with a width of 2 m and the angles are 60 and 45 degrees. And the other recommendations are open channel of a trapezoid shape with 4 categories each of which has a height and a top width of as large as (0,5 m and 2 m, 1 m and 2,5 m, 1,5 m and 3,5 m, 2 m and 4,5 m) and a bottom width of 1 m and an angle of 60 degrees for the entire categories. The recommendation for the downstream part is to create an open channel spillway with dimensions of bottom width of 6 m, height of 2,5 m, and top width of 10,5 m, then engineered the elevation of the pit lake outlet to 21 meters above sea level. The spillway is placed at the point leading to WMP 32 and the drainage facilities at WMP 32 are used to drain overflow water from the pit lake to the river by doing some engineering. In the detention pond, engineering is carried out by making an open channel spillway with dimensions of bottom width 13 m, top width 15,3 m, and height 2 m. The inlet and connectiong channel between the sediment pond compartments were enlarged to be dimensions of 20 m lower width, 21,5 m upper width, and 2 m high. The outlet of sediment pond was enlarged to be dimensions of 8 m lower width, 11,7 m upper width, and height 3,2 m. For the connecting canal to the river its dimensions are enlarged to a bottom width of 9 m, an upper width of 11,9 m, and a height of 2,5 m.