Chemical Characterization of Olaija Coal and its Associated Spoil

Eyitayo Oluwaseyi Ifelola

Mining Engineering Department, School of Mining and Ming Technology, Federal University of Technology, Akure

Keywords: Chemical analysis, Proximate Analysis, Ultimate Analysis, Shale Quality, Coal Ranking, Environmental Impact

Abstract

This study aims to perform a detailed chemical characterization of Olaija coal and associated spoil to evaluate their energy content, environmental impact, and suitability for various industrial applications. The research focuses on classifying the coal and spoil based on proximate and ultimate analyses, with a particular emphasis on determining the best samples for extraction, processing, and environmental management. A randomized sampling technique was employed to collect coal, shale, and soil samples from different locations within the Olaija coal mine. The samples were analyzed according to ASTM standards, speciically ASTM D3172-13 for proximate analysis and ASTM D3176 for ultimate analysis. Elemental analysis was performed using Inductively coupled plasma-mass spectrometry (ICP-MS) technique. Proximate analysis assessed moisture, ash, volatile matter, and ixed carbon content, while ultimate analysis evaluated carbon, hydrogen, nitrogen, sulphur, and oxygen levels. Additionally, the metal contents of the coal and shale were analyzed following ASTM D6357-19, and sulphur content and pH of the soil were measured. The results indicated that MNE/CO/D exhibited superior characteristics among the coal samples, with the highest ixed carbon (30.20%) and the lowest ash content (35.64%), making it the most suitable for higheficiency combustion. In the ultimate analysis, MNE/CO/D also showed the highest carbon content (45.51%) and the lowest nitrogen (2.0%) and oxygen (3.1%) levels. Among the shale samples, MNE/SH/B and MNE/SH/C were identiied as the highest quality, with MNE/SH/C demonstrating the highest carbon content (23.39%) and MNE/SH/B showing the best overall proximate characteristics. Soil analysis revealed variability in pH and sulphur content, with MNE/S/C exhibiting the highest sulphur content and MNE/S/A showing the lowest pH and sulphur levels. The comprehensive chemical analysis identiied MNE/CO/D as the highest quality coal sample due to its favorable combustion properties and low pollutant levels. For shale, MNE/SH/B and MNE/SH/C are the most promising for industrial applications based on their chemical properties. The study highlights the importance of detailed chemical characterization for optimizing resource extraction, assessing environmental impacts, and guiding the management of coal spoil.