A groundbreaking acid-free extraction process for lithium has been developed by researchers at ORNL, promising to revolutionize the way this key element is extracted. The new method, patented by the team, operates at a lower temperature of 140 degrees Celsius and works within a wider pH range of 5 to 11 compared to traditional extraction methods.
The process, based on lithiation and delithiation, involves the use of aluminum hydroxide powder to extract lithium ions from a solvent and regenerate the sorbent, resulting in near-perfect efficiency. The amorphous form of aluminum hydroxide used in the process was found to be highly reactive, leading to greater lithium extraction capacity.
Furthermore, the researchers were able to optimize the process for selectivity, with the sorbent selectively adsorbing lithium ions from liquids containing lithium, sodium, and potassium to form a stable layered double hydroxide sulfate, capturing 37 milligrams of lithium per gram of recoverable sorbent in a single step.
The greener and more efficient process has the potential to significantly impact the domestic lithium supply, with more than half of the world’s land-based lithium reserves located in regions with high concentrations of dissolved minerals. The researchers are now focused on further optimizing the process for speed and efficiency, potentially paving the way for increased lithium production in the United States and reducing reliance on imported lithium.
