Characterizations of Humic Acid Isolated from Coals of Two Nagaland Coalfields of India in Relation to their Origin

In the present study, the humic acid isolated from coals of two coalfields of Nagaland, India has been characterized by Ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD), thermal analysis (TGA-DTA), and scanning electron microscopy (SEM) in relation to their origin. The humic acid reveals a high degree of humification with predominantly aromatic content, which is considered to be type-A humic acid.