GEOCHEMICAL CHARACTERIZATION OF ACID MINE DRAINAGE FORMING IN HIGH-SULPHIDATION EPITHEMAL DEPOSITS CONSIDERING ROCK OXIDATION CLASSIFICATION

• Main Author: Ningsih, Riroh
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/61970
• Institution: Institut Teknologi Bandung

Gold mining activities carried out in open-pit mining have the potential to form acid mine drainage (AAT). Gold deposits are usually associated with sulfide minerals such as pyrite, galena, arsenopyrite, sphalerite and chalcopyrite. Exposure to sulfide minerals in the air and reacting with water will cause acid mine drainage to form. Pyrite oxidation will produce hematite. The presence of hematite is a characteristic of the classification of oxidation in rocks. Therefore, it is necessary to conduct geochemical characterization of rocks to examine whether there is a correlation between rock classification based on oxidation and the potential for acid mine drainage. In this study, geochemical characterization was carried out on 24 rock samples from different batches. Samples 1 through 13 represent batches 1 and samples 14 through 24 from batch 2 in high sulfidation epithermal deposits. Of the 24 samples, static tests, kinetic tests, mineralogy and elemental tests were carried out. The static test consisted of total sulfur, ANC, paste pH and NAG pH. The results of the static test will be confirmed by a kinetic test with the parameters of pH and TDS of the leachate. The results of static tests and kinetic tests can be concluded regarding the final geochemical characterization which can be confirmed from mineralogy and elemental tests for each type of rock oxidation. Completely Oxide showed the presence of hematite with some samples being PAF and NAF. Un oxidized showed the absence of hematite but some samples were PAF and NAF. The classification of rock oxidation cannot represent the potential for acid mine drainage. This is because each classification has a different potential for the formation of acid mine drainage.