Petrographic characteristics of coal from Mailaram coalfield,Godavari valley,Andhra Pradesh

The quantitative maceral study of the Queen seam from Mailaram coalfield of Godavari valley has displayed alternate coal bands rich in vitrinite/liptinite or inertinite. The random vitrinite reflectance (R_o max. %) of these coals, from top part ranges from 0.50 to 0.64%. However, the bottom part of the seam has indicated lower reflectance, between 0.49 and 0.52%. Thus, the Queen seam, in general, has attained high volatile bituminous C rank. The study indicates that the depositional site has been a slowly sinking basin that witnessed alternate dry (oxidizing) and wet (reducing) spells. This subsequently caused fluctuation in water table of the basin and the formation of oxic and anaoxic moor condition, where accumulated vegetal resource transformed into mixed and fusic coal types in due course of time. Being high in liptinite and vitrinite contents and low mineral matter, the Queen seam of Mailaram coalfield has high economic potential.