STUDY OF GEOCHEMICAL CHARACTERISTICS OF ADVANCED ARGILLIC ALTERATION ROCKS IN EPITHERMAL HIGH SULPHIDATION GOLD DEPOSITS

• Main Author: DELILA IMANI SUMANTRI (NIM : 12114092), ALIFIANTY
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25373
• Institution: Institut Teknologi Bandung

Acid rock drainage (ARD) is a water drainage or water seepage caused by mining <br /> <br /> activity process that exposing the rock and characterized by high acidity or the low <br /> <br /> pH value (Gautama, 2014). Mining activity can be done in many type of deposits, <br /> <br /> such as epithermal high sulphidation deposits that have some alteration zone, there <br /> <br /> are silicic, advanced argillic, argillic, and prophyllitic. Advanced argillic <br /> <br /> alteration zone contains native sulphur, and pyrite minerals which are sulphide <br /> <br /> minerals that forming acid rock drainage. The objective of this study was to do the <br /> <br /> prevention, handling and management of acid rock drainage by predicting the <br /> <br /> potential of acid rock drainage formation and predicting the leachate water quality <br /> <br /> of advanced argillic alteration rock samples. <br /> <br /> Based on the tests, there are two classifications for geochemical characteristics of <br /> <br /> rocks : 3 samples of PAF-LC (Potential Acid Forming-Low Capacity) as rocks that <br /> <br /> potentially produce acid rock drainage with weak acidity and 3 samples of PAFHC <br /> <br /> (Potential Acid Forming-High Capacity) as a rock that potentially produces <br /> <br /> acid rock drainage with strong acidity. Leachate water from all samples needs to <br /> <br /> be processed first because the pH of the water is lower than the pH range allowed <br /> <br /> on the quality standard in the Kepmen LH No. 202 Th. 2004 that was 6-9. In <br /> <br /> addition, the dissolved metal content also increases as TDS increases as pH <br /> <br /> decrease, this allows the dissolved metal content to exceed the maximum limit of <br /> <br /> quality standards. Encapsulation methods are needed to minimize rock exposure <br /> <br /> and prevent the formation of acidic conditions capable of dissolving metals.