SIMULATION OF IN SITU ACID MINE DRAINAGE TREATMENT AT PIT LAKE USING FLY ASH IN LABORATORY SCALE

• Main Author: Marialena De Carvalho R, Analia
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/80454
• Institution: Institut Teknologi Bandung

Acidic pit lake water (referred to as acid mine water-AMD) may form when the walls of the mine openings that shape the pit lake are composed a lot of sulfide minerals-containing rocks which oxidize due to exposed to oxygen and water during mining operations. The acidic pit lake water needs to be treated so that it meets the post-mining success criteria to support post-mining land use.One of the options of treatment system that can be implemented is in-situ treatment byalkaline materials addition, one of which is flyash which is ofien produced by powerplant's as waste product. This research was conducted to assess the effectiveness of using fly ash in in situ AMD treatment in pit lakes on a laboratory scale. Geochemical characteristics analysis of fly ash are carried out using static,mineralogical and elemental tests. In situ treatment simulations were carried out using a jar test tool by adding fly ash to acidic pit lake water with 12 (twelve)composition scenarios of 0.3% to 10% by weight. The physical and chemical parameters of the water before and after the addition offly ash were measured and their characteristics analyzed. The fly ash deposits formed were also subjected to mineralogical and elemental analysis. Chemical reaction modeling using PHREEQC sofiware was also carried out to strengthen the analysis. The treatment simulation results show that the addition of 1.5% fly ash has been able to increase the pH of the water to> 6 from the previous 3.45. Dissolved metal concentrations for Fe and Al also decreased significantly (>95%), while for Mn <10%. Mineralogical analysis shows the formation of Hematite (Fe2O3), Goethite (FeOOH) and Gibbsite (Al(OH)3) in fl ash deposits as treatment products which is confirmed by saturation index analysis using PHREEQC software.