DESIGN OF OUT PIT DUMP MINE DRAINAGE IN POST-MININNG SYSTEM (CASE STUDY OF OPD WEST PIT ON 2 SITE LATI MINE OPERATION PT BERAU COAL, BERAU REGENCY, EAST KALIMANTAN)

• Main Author: Fikri Lazuardi, Muhammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69279
• Institution: Institut Teknologi Bandung

In 2022, PT Berau Coal has reached its final design and one of them is Out Pit Dump (OPD) West so that an appropriate post-mining activity design is needed to restore the function of the natural environment and social functions according to local conditions in all mining areas according to UU No. 3 of 2020. Out Pit Dump (OPD) is an area where overburden is piled up where the majority of the material is sandstone and mudstone and contains sulfide minerals that have the potential to produce acid mine drainage (AAT). Therefore, it is necessary to recommend a post-mining system design that will be able to manage water in the West Pit ON 2. Data used is taken from rainfall data for the West (data for the 2013-2018 period), and T3 (data for the 2018-2022 period). The hydrological evaluation in this area is carried out by calculating the value of the planned rainfall intensity using the Mononobe method. Post-mining system recommendations are based on the catchment, runoff discharge, and material balance. The calculation of the trench uses the Manning equation, while the calculation of the drop structure uses the froude number principle. The results in this study indicate that this area has a rainfall intensity of 7.57 mm/hour. The recommended post-mining system chosen is the 3rd option because the resources and effort required are effective with a material balance of around 800 thousand cubic meters for both cutting and filling. OPD West Pit ON 2 Berau Coal has a total catchment 3.91 k????2 which is divided into 18 subcatchment. With the intensity of rain and the distribution of catchment, drainage facilities are needed in the form of 2 (two) categories of open channels and 18 drop structures.