STUDY OF CHARACTERIZATION OF MIXING MATERIAL OF POTENTIALLY ACID FORMING (PAF) AND FLYING ASH (FLY ASH) IN MANAGING MINE ACID WATER ON THE LABORATORY SCALE

• Main Author: Dewandari Kusuma Wardani, Yessy
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/43981
• Institution: Institut Teknologi Bandung

One method that can be used to prevent the formation of acid mine drainage is to mix material that has the potential to form acid (Potentially Acid Forming / PAF) and material that has no potential to form acid (Non Potentially Acid Forming / NAF). Fly ash, which is a hazardous waste, can be used as a mixed material to prevent the formation of acid mine drainage due to its small size and alkaline nature which is expected to neutralize the pH of acidic water. Characterization was carried out using several tests, including: mineralogical tests (XRF and XRD), rock physical tests, static tests (Acid Base Accounting, pH Paste, and Net Acid Generating), and kinetic tests (Free Draining Column Leach Test). The PAF sample used is the cover rock of PT Kaltim Prima Coal with a size of +2 mesh, +3 mesh, and -3 mesh and fly ash from the Asam Asam power plant which is near the mining location of PT Arutmin Indonesia. The research was conducted with several compositions of PAF and fly ash mixing based on variations in grain size of PAF and variations in the addition of fly ash. In the variation of the addition fly ash, fly ash which has a large enough acid neutralizing capacity, namely ANC of 259.95 kg H2SO4 / ton can be used as a mixture material to neutralize acid mine drainage (pH values are in the range of 8-10). The ability of fly ash in neutralizing acid decreases as indicated by the decrease in the pH value of the mixture in the three-day cycle (from range 7-8 down to range 3-4) and a decrease in the pH of fly ash material (from range 8-10 down to pH 8). From the test results of PAF grain size variation, smooth fly ash can be used to prevent oxidation reactions in acid formation by filling the pore granular PAF. Physical changes in the material occur in a three-day cycle, cracks formed made porosity increased, resulting in an oxidation reaction (pH drops from the range of 6-7 to 3-7).