ENHANCING EXTRACTION OF RARE EARTH ELEMENTS FROM WEST VIRGINIA BITUMINOUS COAL

Rare earth elements (REE) are essential for manufacturing technologies vital to economic and national security. As the demand for REE increases and conventional ores are depleted, attention has turned to coal as a promising unconventional resource for these elements. As the nation’s second-largest coal producer, West Virginia (WV) can transition into the production of these critical elements. But it is imperative to understand REE modes of occurrence in these coals in order to identify promising coal seams and design efficient extraction techniques. To this end, four WV bituminous coal samples were subjected to a standard sequential leaching process to quantify REE concentrations and identify their modes of occurrence. The leaching procedure targeted individual coal fractions including ion-exchange sites; carbonates, oxides, and monosulfides; pyrite and phosphates; and organic matter. More than 50% of the extracted REE in each sample were leached from the HCl-soluble carbonate, oxide, and monosulfide fraction. However, overall extraction efficiency was very low (<5%), indicating that the majority of REE are contained within silicate minerals or other resistant phases. Additional experiments will be conducted to identify more efficient extraction techniques for WV coals, using a combination of roasting additives and acid leaching.