Rare-earth elements in coal

With a growing demand for rare-earth elements, such as scandium, yttrium, lanthanum and cerium, necessary to produce high-tech equipment used in health care, transportation, electronics and other industries, the extraction of these elements from coal becomes commercially viable soon.

According to a team of Penn State and U.S. Department of Energy researchers, the U.S. could soon decrease its dependence on importing valuable rare-earth elements (REEs) that are widely used in many industries. They have found a cost-effective and environmentally friendly way to extract these metals from coal byproducts. «We have known for decades that REEs are found in coal seams and near other mineral veins,» says Sarma Pisupati, professor of energy and mineral engineering, Penn State. «However, it was costly to extract the materials and there was relatively low demand until recently. Today, we rely on REEs for the production of many necessary and luxury items, such as computers, smart phones, rechargeable batteries, electric vehicles, magnets and chemical catalysts. So, we took a fresh look at the feasibility of extracting REEs from coal because it is so abundant in the U.S.» The team reported that ammonium sulfate was both environmentally friendly and able to extract the highest amount of rare-earth elements. Extracting 2 percent of the available REEs would provide an economic perspective to companies. The researchers used coal byproducts in their study, some of which were discarded or marked as refuse during mining operations due to poor quality. Finding more uses for discarded coal could provide yet another economic benefit to companies. The full article was published on phys.org.