EVALUATION OF DRAINAGE SYSTEM STRATEGIES FOR PIT ZONE AND BUFFER POND DUE TO PHASE CHANGES IN MINING ACTIVITIES AT ABC MINE SITE PT XYZ

• Main Author: Yasyin A R S, Mohammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/76836
• Institution: Institut Teknologi Bandung

The open-pit mine, ABC, owned by PT XYZ, is planning to make changes to its mining phase, where the latest phase involves pit floor lowering. One crucial aspect to be considered is water management to ensure that mining operations on the pit floor can be conducted for at least 9 months in a year. Hence, an analysis and evaluation are required to determine whether the existing drainage system strategies in the Pit and buffer pond zones can accommodate the needs of the new mining phase. The data used includes secondary data from PT XYZ, which comprises daily rainfall data, topographical data for each year until the end of mine life (LOM), water network schematics, and the capacity of the retention ponds, as well as the maximum pump discharge rate. The evaluation is conducted using weekly plan rainfall based on the probability from its cumulative distribution function. The research results indicate that with the existing drainage system strategy, the Pit will be flooded for more than 3 months at a rainfall probability above P 75%. One option that can be considered is changing the water network scheme, specifically redirecting the overflow flow from Sediment Reclaim Pond (SRP) back to Emergency Pond (EP) before it is discharged into the Pit when EP is full. Additionally, another option is to add a pump with a discharge rate of 2200 m3/hour into the Pit. This option results in the Pit being flooded for more than 3 months at a rainfall probability above P 95%, with a maximum water inundation volume of 1,8 million m3.