STUDY OF ROCK GEOCHEMICAL CHARACTERIZATION IN ACID MINE DRAINAGE GENENATION OF HIGH-SULPHIDATION EPITHERMAL

• Main Author: AIMUNANDAR JAYAPUTRA (NIM : 22116019), HARSALIM
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/27757
• Institution: Institut Teknologi Bandung

Acid Mine Drainage (AMD) could be generated from rocks in High Sulphidation Epithermal gold deposit (HSE). HSE deposit is characterized by mineralization in alteration zones. This study aims to find relation between alteration type in HSE gold deposit and its geochemical characterization. Rock samples were taken from various alterations in HSE gold deposit, i.e silica massive, advanced argillic and argillic alteration. Geochemical characterization was carried out by conducting static test, kinetic test, mineralogical test and water quality test for leachates from kinetic test. The test results showed that samples from silica massive alteration (HS1 and HS2) gave different geochemical characterization: sample HS1 is characterized as Potentially Acid Forming (PAF) High Capacity, whilst sample HS2 is characterized as PAFLC. Samples from advanced argillic alteration (HS3 and HS4) also gave different geochemical characterization HS3 as PAF-HC, HS4 as NAF. The same variance of geochemical characterization also showed in samples from argillic alteration (HS5 and HS 6), which HS5 is classified as PAF-LC and HS6 as PAF- HC. Reactive acid-producing minerals are present in silica alteration described in HS1. Advanced argillic alteration has the same potential as acid or acid neutralizers with characteristics in samples HS3 and HS4. The last Argillic alteration is classified as PAF material with the characteristics pH <4.5 with low TDS values as described in HS5. Based on geochemical characterization results for all alterations, it is concluded that alteration type is not directly related to geochemical characteristic of AMD generation.