Water Quality Analysis in Coal Washeries

Abstract

Water is the most important element of eco-system and it is thus imperative to determine and mitigate the effects of mining operation on the same. Also, contaminated water has adverse physiological effects on human being and other animals. For this, it is important to identify the critical parameters in the water sample which is the scope of the study. Therefore an attempt made to analyze the characteristics of the effluent that comes from the three coking coal washeries of Central Coal fields Limited in certain Kedla Coal washery, Rajrappa Coal washery and Kargali Coal washery in Jharkhand state, India. For this study, raw water or the intake water to the washery, fine coal jig water, coarse coal jig water and slurry lake water were collected from the three washeries. Parameters illustrated in Ministry of Environment and Forest (MoEF) Schedule VI Indian principles (2006) were determined along with the sodium, potassium, magnesium, manganese, calcium in the washery effluent samples. The pH is observed to be decreased in the process water. The concentrations of major elements in coal—Na, K, Ca and Mg were found to be higher in process water than in raw water indicating that these elements are transferred from coal to the water in washeries. However, only in the case of Mn, the stipulated limit of the effluent standard was exceeded. Trace elements like As, Se, Cd, though found to be present in coal, were absent in the process water indicating that these elements are not released by coal during washing