Mechanochemical Lithium Extraction and Zeolite Synthesis from End-of-Life Glass-Ceramics

Lithium has become a strategic element, as it plays a crucial role in battery technology. Therefore, many efforts are being made to extract lithium from primary sources, while lithium recycling is almost nonexistent. In this paper, we report on a novel alkaline mechanochemical approach for the recycling of end-of-life glass-ceramics, which involves lithium extraction, zeolite synthesis, desilication, and lithium precipitation. Special attention has been paid to a holistic approach, with each byproduct having a designated application. Optimal parameters for lithium extraction such as sodium hydroxide concentration, rotational speed, and ball-to-powder ratio were achieved at 7 mol/L, 600 rpm, and 50:1 g/g, respectively, resulting in high yields of 83.8% (60 min) and 92.4% (120 min). Desilication of the solution resulted in a removal efficiency of 96.3% with calcium silicate as a value-added byproduct. Lithium could be recovered as phosphate with a high purity by adding phosphoric acid. Moreover, the zeolites synthesized during this investigation were analyzed by powder X-ray diffraction, Fourier transform infrared spectroscopy, and N2adsorption/desorption analysis. In addition, selected zeolite samples were investigated as potential adsorbents for the removal of heavy metal ions (Cu2+, Ni2+, Pb2+, and Zn2+) from aqueous solutions.