PREDICTION WATER QUALITY OF THE FUTURE PIT LAKES IN COAL MINE PT. JORONG BARUTAMA GRESTON, SOUTH KALIMANTAN

• Main Author: KEZIA EKA SAPUTRI (NIM : 22108310), ERIKA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/20075
• Institution: Institut Teknologi Bandung

Coal resources in Indonesia is a lot, especially in Kalimantan and Sumatra. Government of national energy policy in 2025 that coal consumption expected to reach 33% (source: UU No: 30 Tahun 2007),this caused the increasing of existing coal mines in Indonesia. Acid Mine Drainage (AMD) often appear as environmental problems in coal mine or ore mine. Acid Mine Drainage (AMD) is leached liquid, seepage or drainage, which has low pH and the water has been reaction with the mineral of rock like oxidization process with sulphide minerals. Seeing the problem of acid mine drainage in the PT. Jorong Barutama Greston, need a study of the existing pool of mined either already filled with water or unfill with water. Acid mine drainage problems arise in Jorong, where are shown by the pH value of 3 in water of the Pit M4E, M1E and the UE. Therefore it is necessary for prediction of water quality, especially pH in the water that will be fill the pit. By knowing the water quality will be formed in the future, can be too predictable to be done or methode to design any treatment or preventing the formation of AMD. Prediction of water quality in the pit conducted with the helped of PHREEQC program, the program is running the calculation with consideration of chemical. Prediction using two scenarios, where the scenario I assumed distribution of minerals on the pit wall is prevalent. While in scenario II is assumed distribution of minerals on the pit wall is uneven. The difference lies spread that occurred at the high wall and low wall. Scenario I produce a range of values of pH lower end when compared to scenario II in the pit UC_West, UC_East and M4E_Nahiya, ie from 3.14 to 5.48, 3.14 to 5.48 and from 2.88 to 6.15. While in the pit M45C range produced the same final pH values in both scenarios, ie from 3.24 to 6.51. This occurs because the minerals in the high wall and low wall has the same kind. scenario II to produce the final value of pH 4.13 to 5.38 for the pit UC_West, 4.13 to 5.38 for pit UC_East and 3.76 to 6.07 for pit M4E_Nahiya. In this scenario, the simulation is based on the distribution of the mineral in the field.