Separation of Lithium from Ores in Seconds

Lithium (Li) is the lowest density metal, and therefore an optimal element in most battery designs1,2. With the increasing demand for Li, metallurgical techniques using excess acid leaching of mineral ores are common. However, these techniques are limited by complex, multi-step processes with adverse environmental impacts caused by secondary waste streams1,3. Here, we show that flash Joule heating (FJH) can convert the earth-abundant Li ore, alpha-spodumene, into beta-spodumene in seconds, making LiCl extractable with 1 M HCl (Method A). Even more simply, we show that a one-step FJH of alpha-spodumene under an atmosphere of Cl2 (FJH-Cl2) can afford high-purity and high-yield LiCl in seconds without any acid treatment (Method B). This capitalizes upon the lower DeltaGform of the LiCl over the competing aluminum and silicon chlorides. Spodumene undergoes the FJH-Cl2 reaction at 1550 °C in seconds, whereupon LiCl immediately distills from the remaining non-volatile aluminum oxide and silicon oxide. LiCl with a 96% purity and 94% yield can be achieved in this rapid one-step process, enormously reducing costs and waste emissions. Local processing with FJH-Cl2 can dramatically lessen the complexity and cost in obtaining Li, obviating remote mining, and facilitating the world’s progression toward cleaner renewable energies2,3.