CHARACTERIZATION OF RARE EARTH ELEMENTS IN WEST VIRGINIA GOB PILES

Garbage of bituminous waste (GOB) are the remnants of bituminous coal mining activities left at, near, and around coal mines. GOB piles are made of a mixture of coal, shale, bone coal, and metallic minerals from a blend of floor and ceiling rock¾typically clay and shale¾with lost lower-grade coal. The material can pose significant environmental consequences and hazardous risks even after remediation and reclamation efforts. In recent years, global politics have magnified the need to identify domestic sources of rare earth elements (REE) and critical minerals (CM). The Central Appalachian coal basin (CAB) hosts numerous expansive GOB piles, and the presence of metallic minerals in the discarded shale and coal could be advantageous if they are found to contain sufficient REE. Characterization of GOB pile material from the CAB is the first step toward evaluating the waste material as a resource and to inform future reclamation efforts. A backpack drill was used to collect vertical core samples of refuse material from two GOB piles in West Virginia. A subsample from each depth was analyzed by portable X-ray fluorescence (pXRF), inductively coupled plasma mass spectrometry (ICP-MS), and thermogravimetric analysis (TGA). The results of this work are important to developing more robust and upscaled methods to better estimate element concentration, pile volume, and provide the data necessary to develop cost-effective extraction methods. Reclamation and processing of GOB piles could result in supplement to domestic REE/CM supply chains and further remediation of environmental hazards caused by the piles remaining in place.