GEOCHEMICAL ATTRIBUTES OF SELECTED NIGERIAN COALS: IMPLICATIONS FOR GRADE AND UTILIZATION

Abstract

The geochemical attributes which include the proximate and ultimate characteristics of coals were analyzed on selected Nigerian coals to determine their grade and utilization. The key parameters analyzed included moisture content (MC), ash content (AC), volatile matter (VM), phosphorus (P), organic carbon (OC), fixed carbon (FC), total nitrogen (TN), total sulfur (TS), gross calorific value (GCV), and free swelling index (FSI). The conventional methods of coal analyses under the appropriate American Standard for Testing and Measurement (ASTM) and International Standard Organization (ISO) were employed in the coal analysis. The results of the various analyses revealed that moisture content varied across the coals, ash content indicated a significant range, suggesting varying degrees of mineral impurities, moderate to high volatile matter content, indicating good combustibility, phosphorus and organic carbon content varied widely, impacting the coal’s suitability for industrial applications, fixed carbon content reflected a range from lignite to bituminous coal, correlating with the samples’ energy potential, as indicated by GCV values. These values of the analyzed parameters classify the coals into lignites, sub-bituminous to bituminous grades with various possible utilizations based on the geochemical attributes of the studied coals