Geological and geochemical assessment of coal deposits at Lamja Sama, Yola sub-basin, Northern Benue Trough, Nigeria

Abstract

Coal remains a significant energy resource for socioeconomic development, especially in countries like Nigeria. The work helped unlock the potential of coal deposits in the Northern Benue Trough and assess their suitability for industrial use. This study presents a geological and geochemical assessment of coal deposits at Lamja Sama, Northern Benue Trough, Nigeria. The research aims to characterise the coals, determine their rank, and evaluate their potential industrial applications. The work entailed geological mapping of outcrops, with data systematically recorded and plotted to produce a geological map and lithostratigraphic logs. Sandstone, siltstone, shale, limestone, marlstone and coal are among the lithological units found in the study area. The lithostratigraphic logs explain the position of coal seams and other lithological units. Representative coal samples were collected from seams in two different areas and subjected to proximate and ultimate analyses to determine properties such as moisture content, volatile matter, ash content, fixed carbon, sulfur, nitrogen, oxygen, and hydrogen. The geochemical analyses indicate that the coal samples from Lamja Sama are classified as medium-volatile bituminous coal, with a fixed carbon content of less than 78% and volatile matter content greater than 22%. Based on the results of proximate and ultimate analyses, the coal contains a quantifiable amount of carbon, making it a potential primary heat source for furnaces and boilers. In addition, carbon content is a key determinant of the heating value of coal, making it suitable for power generation. However, owing to the high ash content, this coal may benefit from blending with coals of lower ash content to improve its overall performance.