SEM study of some Indian natural cokes (jhama)

Abstract

Scanning Electron Microscopy (SEM) is an indispensable tool for studying the mineral and organic matrix, particularly in the baked coals or natural cokes, which form due to magmatic intrusion (dykes and sills) in coal seams. In this paper this tool has been used to demonstrate the relationship between morphology and genesis of natural coke or jhama samples derived from Damodar Valley Coalfields of India. The SEM studies were carried out using JEOL-840A JSM under magnifications ranging from 200X to 50000X on selected heat altered coal/natural coke, CPC and graphite samples to decipher the microstructures of these samples and comparative studies. The chips of coal lithotypes, heat altered coal/natural cokes, CPC and graphite, of about 1cm size were isolated from the coal blocks using hammer, chisel and forceps and were washed with alcohol to remove the superficial dust and mounted on brass stubs using silver paste as glue and coated with gold (thickness about 400A°).