Extraction and Evaluation of Rare Earth Metals from Kogi Coal for Petroleum and Gas Industry Application

Abstract Rare-earth elements (REE) are necessary components of more than 200 products across a wide range of applications, especially high-tech consumer products, such as cellular telephones, computer hard drives, electric and hybrid vehicles, and flat-screen monitors and televisions. This research aims to extract rare earth elements (REEs) from Kogi coal, tackling challenges like low concentrations and environmental concerns. The method involves acid leaching with 0.4 mol/l sulfuric acid, followed by solvent extraction using di-(2-ethylhexyl) phosphoric acid (D2EHPA) and kerosene. The optimal D2EHPA concentration is 5% for heavy REEs (HREE) and over 25% for light REEs (LREE). REEs are then stripped from the solvent with hydrochloric acid. Concentrations are measured using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). This study underscores the importance of efficient and sustainable REE extraction from coal, essential for meeting global demand amidst evolving environmental concerns and technological advancements. The coal used resembles Bituminous Coal based ion its analysis. The leachate turned black, indicating successful transfer of coal ash constituents. Immiscible-liquid solvent extraction yielded separate phases for HREEs and LREEs. HREEs, especially Terbium (Tb), Dysprosium (Dy), and Gadolinium (Gd), were extracted more efficiently with 0.022mg/L, 0.021mg/L and 0.021mg/L respectively compared to LREEs, notably Lanthanum i(La), Samarium (Sm), Scandium (Sc), and Cerium (Ce) with 0.015mg/L, 0.015mg/L, 0.012mg/L and 0.011mg/L respectively. This research highlights the potential of coal reserves as a critical source of REEs and emphasizes the necessity of advanced extraction techniques.