PHYSICAL AND GEOCHEMICAL CHARACTERIZATION OF BLENDING MATERIAL OF POTENTIAL ACID FORMING AND FLY ASH BY APPLYING FREE DRAINING COLUMN LEACH AND HUMIDITY CELL TEST METHODS OF LABORATORY KINETIC TEST

• Main Author: Ilham Kadar, Muhammad
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/46369
• Institution: Institut Teknologi Bandung

Acid Mine Drainage (AMD) is an important environmental issue in mining activities Acid Mine Drainage (AMD) is an important environmental issue in mining activities that needs to be prevented. One of the prevention methods is by mixing PAF (Potential Acid Forming) rocks and NAF (Non Acid Forming) rocks. But, NAF rocks in the mining site is in limited stock. NAF rocks could be subtituted by Fly Ash which is collected from the mine mouth power plant. Previous research in preventing the formation of AMD by mixing methods has shown the ability to neutralize or prevent AMD on a laboratory scale. Therefore it is necessary to conduct further study to identify whether physical and geochemical parameters are more influential on mixing performance. The study is begun by grain size distribution test. Then, it is continued by static test, X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF), laboratory kinetic test (FDCLT and HCT), also ions and elements content in leachate. Geochemical test is purposed to estimate the net acid generating potential of PAF material and acid neutralizing capacity of FA. Free draining column leach test (FDCLT) and humidity cell test (HCT) are applied in order with blending simulation. Analyzing process is started by identifying the influence of grain size variation in PAF material (coarse and fine grained) on variation of additional amount of FA (5%, 10% dan 20%), followed by leachate quality analyzing and pyrite oxidation rate calculation of blending material. Based on this study, it is concluded that the grain size variation of PAF materials has no effect on the leachate quality. The greater the fly ash ratio, the higher the alkalinity capacity, which is making the pyrite oxidation rate will be lower. PAF-FA (20%) sample is the most effective mixing simulation in order to prevent and neutralize the AMD generation in 10 weeks. It is proven by sulphate and alkali ratio which is close to balance point. Different condition on FDCLT and HCT can control physical condition of sample and also determine the geochmical characteristic of leachate. This factor must be a concern in calculating the AMD generation rate.