Microwave-assisted extraction of lithium from hectorite clay

Transition to renewable energy sources, rapid rise in the use of Li-ion batteries for energy storage has warranted a search for efficient lithium extraction methods from low grade lithium ores such as clays and sediments since supply from conventional sources is insufficient to meet the increasing demand. In this effort, classical base – acid – carbonate method was found to be ineffective for the extraction of lithium from minerals with very low lithium content such as hectorite clay with of 0.137 ± 0.004 % (w/w) lithium. The key finding in this work is a new microwave heating assisted base – acid – carbonate method for the extraction of lithium from low lithium content clay minerals, where lithium could be extracted from hectorite clay mineral in 98% efficiency as lithium carbonate. Leaching of lithium from hectorite clay was evaluated by studying Scanning electron microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX) analyses, ATR-IR and X-ray crystallography of hectorite and leach residues.