Coal characterization and occurrence of rare earth elements in coal and coal-ash of Sohagpur Coalfield, Madhya Pradesh, India

Coal is a valuable source for power energy as well as for metal contents within it. Coal and its by-product are considered a promising resource for the critical elements and rare earth elements (REEs). The study of REEs in coal is in its infancy. This paper focuses on REEs’ occurrence, qualitative, and quantitative in coal and its by-products (shale coal, shale coal ash, and coal ash) of Sohagpur Coalfield, Madhya Pradesh, India. The collected coal samples were analyzed by scanning electron microscope with energy-dispersive X-ray analysis, inductively coupled plasma mass spectrometry, bomb calorimeter, thermogravimetric analysis, and ultimate analysis. The REEs’ concentration of Sohagpur Coalfield was also compared with the Chinese coal, US coal, and world coal average. The average content of critical REEs for Y is 51.49 ppm, for Nd is 79.34 ppm, for Eu is 2.67 ppm, for Tb is 1.71 ppm, and for Dy is 9.76 ppm in samples. The highest average values of REEs reported for Ce are 58.15 ppm in coal and 187 ppm in coal ash by-products. Coal by-products of the collected samples are a good resource for REEs than the Chinese coal, US coal, and world coal averages.