JEP  Vol.3 No.7 , July 2012
An Evaluation on the Physical and Chemical Composition of Coal Combustion Ash and Its Co-Placement with Coal-Mine Waste Rock
In the last few decades, the utilization of coal to generate electricity was rapidly increasing. Consequently, the production of coal combustion ash (CCA) as a by-product of coal utilization as primary energy sources was increased. The physical and geochemical characteristics of CCA were site-specific which determined by both inherent coal-source quality and combustion condition. This study was intended to characterize the physical, chemical and mineralogical properties of a coal-combustion ash (CCA) from a site specific power plant and evaluate the leachate characteristic of some scenario on the co-placement of CCA with coal-mine waste rock. The physical properties such as specific gravity, dry density, porosity and particle size distribution were determined. Chemically, the CCA sample is enriched mainly in silica, aluminum, iron, and magnesium along with a little amount of calcium and sodium which includes in the class C fly ash category. Moreover, it is found that the mineral phases identified in the sample were quartz, mullite, aragonite, magnetite, hematite, and spinel. Co-placement experiment with mudstone waste rock shows that the CCA, though it has limited contribution to the decreasing permeability, has important contributed to increase the quality of leachate through releasing higher alkalinity. Moreover, addition of CCA did not affect to the increase of the trace metal element in the leachate. Hence, utilization of CCA by co-placement with coal mine waste rock in the dumping area is visible to be implemented.

Cite this paper
G. J. Kusuma, H. Shimada, T. Sasaoka, K. Matsui, C. Nugraha, R. S. Gautama and B. Sulistianto, "An Evaluation on the Physical and Chemical Composition of Coal Combustion Ash and Its Co-Placement with Coal-Mine Waste Rock," Journal of Environmental Protection, Vol. 3 No. 7, 2012, pp. 589-596. doi: 10.4236/jep.2012.37071.
[1]   L. J. Wibberley and T. F. Wall, “An Investigation of Factors Affecting the Physical Characteristics of Flyash Formed in a Laboratory Scale Combustor,” Combustion Science and Technology, Vol. 48, No. 3-4, 1986, pp. 177-190

[2]   M. B. Yeheyis, J. Q. Shang and E. K. Yanful, “Characterization and Environmental Evaluation of Atikokan Coal Fly Ash for Environmental Applications,” Journal of Environmental Engineering and Science, Vol. 7, No. 5, 2008, pp. 481-498. doi:10.1139/S08-019

[3]   W. Stumm and J. J. Morgan, “Aquatic Chemistry: An Introduction Emphasizing Chemical Equilibria in Natural Waters,” 3rd Edition, John Wiley and Sons, New York, 1996.

[4]   A. Xenidis, E. Mylona and I. Paspaliaris, “Potential Use of Lignite Fly Ash for the Control of Acid Generation from Sulphidic Wastes,” Waste Management, Vol. 22, 2002, pp. 631-41.

[5]   R. S. Gautama, G. J. Kusuma, I. Lestari and R. P. Anggana, “Weathering Behaviour of Overburden-Coal Ash Blending in Relation to Overburden Management for Acid Mine Drainage Prevention in Coal Surface Mine,” 2010.

[6]   R. Pérez-López, J. M. Nieto and G. R. de Almodóvar, “Utilization of Fly Ash to Improve the Quality of the Acid Mine Drainage Generated by Oxidation of a Sulphide-Rich Mining Waste: Column Experiments,” Chemosphere, Vol. 67, No. 8, 2007, pp. 1637-1646. doi:10.1016/j.chemosphere.2006.10.009

[7]   W. Gitari, L. Petrik, O. Etchebers, D. Key, E. Iwuoha and C. Okujeni, “Passive Neutralisation of Acid Mine Drainage by Fly Ash and Its Derivatives: A Column Leaching Study,” Fuel, Vol. 87, No. 8-9, 2008, pp. 1637-1650. doi:10.1016/j.fuel.2007.08.025

[8]   ASTM (D422), “Standard Test Method for Particle Size Analysis,” ASTM International.

[9]   ASTM (D854), “Standard Test for Specific Gravity of Soil Solids by Water Pycnometer,” ASTM International.

[10]   ASTM (D1557), “Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort,” ASTM International.

[11]   D. P. Mishra and S. K. Das, “A Study of Physico-Chemical and Mineralogical Properties of Talcher Coal Fly Ash for Stowing in Underground Coal Mines,” Materials Characterization, Vol. 61, No. 11, 2010, pp. 1252-1259. doi:10.1016/j.matchar.2010.08.008

[12]   P. Y. Chen, “Table of Key Lines in X-Ray Powder Diffraction Patterns of Minerals in Clays and Associated Rocks,” 1977.

[13]   A. A. Sobek, W. A. Schuller, J. R. Freeman and R. M. Smith, “Field and Laboratory Methods Applicable to Overburden and Minesoils,” 1978.

[14]   AMIRA International, ARD Test Handbook, 2002.

[15]   ASTM (C618-08), “Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete,” ASTM International.

[16]   Q. Xu and J. Fan, “Self-Cementitious Property of High Calcium Fly Ash,” Coal ash China, No. 6, 1994, pp. 23-27.

[17]   E. L. Ye, “Self-Harden Mechanism of High Calcium Fly Ash,” Housing Materials & Applications, No. 5, 1996, pp. 40-42.

[18]   I. A. Sadisun, H. Shimada, M. Ichinose and K. Matsui, “Study on the Physical Disintegration Characteristics of Subang Claystone Subjected to a Modi?ed Slaking Index Test,” Geotechnical and Geological Engineering, Vol. 23, 2005, pp. 199-218.

[19]   S. Devasahayam, “Application of Particle Size Distribution Analysis in Evaluating the Weathering in Coal Mine Rejects and Tailings,” Fuel Processing Technology, Vol. 88, No. 3, 2007, pp. 295-301. doi:10.1016/j.fuproc.2006.10.013

[20]   N. Takeno, “Atlas of Eh-pH Diagrams,” Geological Survey of Japan Open File Report, 2005.