Static and Dynamic Leaching Studies on Coal Gangue
In the present study, an attempt has been made to determine the leachability of selected trace metals like As, Cr, Co, Se, Ni, Cu, Zn, Cd, Pb and Mn from coal gangue sourced from an underground and open cast mining area(s) of Bhupalpally Coalfields of Tel
- PDF / 419,211 Bytes
- 10 Pages / 439.37 x 666.142 pts Page_size
- 92 Downloads / 240 Views
Abstract In the present study, an attempt has been made to determine the leachability of selected trace metals like As, Cr, Co, Se, Ni, Cu, Zn, Cd, Pb and Mn from coal gangue sourced from an underground and open cast mining area(s) of Bhupalpally Coalfields of Telangana State, India. A standard laboratory leaching test (dynamic in nature) developed for combustion residues has been adopted to study the leachability of these trace elements as a function of liquid to solid ratio and pH. A series of static column leaching tests were also conducted to investigate the leachability of these selected heavy metal ions simulating field conditions. The column tests revealed that heavy metals from coal gangue exhibit greater mobility particularly under acidic conditions. Further, relatively higher concentrations were leached for both static and dynamic leaching conditions at low pH levels and is attributed to the difference in solubility product values of respective metal ion complexes. Among the targeted metal ions, with a metal extraction of 30% and 65%, respectively, As and Se showed highest mobility from both static and dynamic leaching tests. Keywords Coal gangue · Trace metal elements · Leaching
1 Introduction Mining is a primary activity in obtaining minerals and fossil fuels that produce enormous amounts of waste, which is a continuous source of contamination posing a threat to the surrounding environment [1]. In India, coal is the fundamental source of fuel for the production of commercial energy. Coal mining is often associated with the generation of huge volumes of wastes at various stages of its extraction and waste generated during the mineral processing phase is popularly known as ‘coal gangue’. Of the total mining waste, coal gangue alone accounts to 20–40% and it is characterised by its diversity in grain size and petrographic composition [1–4]. Among the industrial solid wastes, coal gangue is one of the largest and most harmful wastes M. Ashfaq · M. Heera Lal · A. A. B. Moghal (B) Department of Civil Engineering, National Institute of Technology Warangal, Warangal 506004, Telangana, India e-mail: [email protected] © Springer Nature Switzerland AG 2020 K. R. Reddy et al. (eds.), Sustainable Environmental Geotechnics, Lecture Notes in Civil Engineering 89, https://doi.org/10.1007/978-3-030-51350-4_28
261
262
M. Ashfaq et al.
generated from the coal production process [5]. Currently, coal gangue is loosely stockpiled at the mining sites and annual accumulative stockpiles of coal gangue in India are to an extent of 550 million tonnes [6]. The disposal of such a large amount of coal gangue induces many environmental and ecological issues like the contamination of soil and underground water bodies. Coal gangue is used extensively as a raw material in thermal power plants to effectively leverage its calorific value. Though, such utilisation measures of reducing the amount of coal gangue can yield immediate economic benefits but can give rise to serious environmental implications. Exploring avenues for sustainabl
Data Loading...
