Bloomington Leader

Researchers at the Indiana Geological and Water Survey are exploring coal waste as a potential domestic source of critical minerals and rare earth elements. Such elements are integral to modern technologies, including smartphones, hybrid cars, and plane radar. A few countries currently dominate these resources, leading to growing global demand and potential supply chain concerns.

Maria Mastalerz from the Indiana Geological and Water Survey, a key figure in this research, is leading investigations on the state's coal mine waste. Indiana's extensive history of coal mining has left behind abundant waste, which includes over 100 million tons of fine-grained coal preparation plant refuse and about 50 million cubic meters of coal ash.

The research aims to assess whether this waste could become a viable source of rare earth elements, crucial for reducing foreign dependency and fostering domestic manufacturing growth. Mastalerz expressed the importance of identifying enriched areas and understanding their occurrences for realistic evaluation. The U.S. Department of Energy supports this effort in collaboration with the Illinois State Geological Survey.

Rare earth elements, though not truly rare, are typically found in challenging-to-extract conditions. China has historically led production, controlling substantial market shares, though this has decreased slightly over the past decade. In Indiana, black shales and fossil soils from ancient geological periods are also being studied for potential mineral content.

Researcher Bei Liu indicated that, presently, most geological samples from Indiana do not reach the U.S. Geological Survey's extraction thresholds. Yet, this could change if market demands increase or extraction technologies improve.

All related Indiana Geological and Water Survey studies have received backing from the U.S. Department of Energy and the U.S. Geological Survey. Future studies focus on creating a regional element and mineral database to support resource evaluation across the Midwest.

Liu emphasized the need to thoroughly understand the available resources before advancements in technology could make extraction feasible.