Researchers writing in the International Journal of Oil, Gas and Coal Technology, say that lithium has been found commonly in coal deposits and is potentially extractable. They suggest that extracting rare metals—such as lithium—from coal, could be a cleaner, more efficient and economical way to use fossil fuel resources.

According to the scientists, two analytical techniques—inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma as an excitation source (ICP-AES)—are widely used for assaying the chemical elements in coal and coal ash. They say that either of these techniques could be used to optimize sources for lithium, or any given metal, for subsequent extraction.A loader transporting coal in a coal mine. Source: aiche.org

Researchers also have looked into two techniques for lithium extraction: one involves sulfur sintering in the ash and acid leaching the metal from the solution to obtain lithium carbonate, and the other uses alkali sintering, avoiding the use of sulfur. Although the investigation into lithium recovery from coal ash is still at a laboratory scale, they see this application as the green, efficient and beneficial way to the lithium-demanding industry.