WATER QUALITY SIMULATION MODEL OF COAL PIT LAKES IN PIT D2 BINUNGAN SITE PT BERAU COAL, EAST KALIMANTAN

• Main Author: Widowati, Danis
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69298
• Institution: Institut Teknologi Bandung

Coal mining activities are generally carried out using the open pit mining method. Large scale excavation without backfilling activity can lead to the formation of a big hole (void) at the end of mining activity. Post-mining lakes (pit lakes) can form if the voids are filled with water. D2 Pit located in Binungan Mine Operation 01 Site, which will be closed in September 2022 and the void will be left to be filled with water. The water quality measurements at the sump of D2 Pit showed low pH value of 3,18 and potential to form acid mine drainage in D2 Pit. In this study, simulation model for water quality was carried out using PHREEQC with a ratio of the pit wall lithological surface area in D2 Pit. The water quality shows the pH value of 5.64 and the remaining values of Fe and Mn metals are 211,57 mg/L and 3,51 mg/L at the end of the pit lake formation.