Lithium Recovery from Boron Processing Wastes via Mechanical Activation-Assisted Water Leaching: Application of Planetary Milling

In this study, a more sustainable, cost-effective, and environmentally friendly approach for selective lithium extraction via water leach assisted by planetary mill mechanical activation was applied on clayey wastes of the Kırka Boron Plant. A detailed systematic study on wastes was performed to optimize both mechanical activation and leaching conditions and to characterize the active powders by XRD, FTIR and EDS/EDX. The results show that lithium can be recovered at relatively low leach temperatures of 50–60°C and short leach times of 3–5 min, achieving leach recoveries of 44.71 (without salt addition) and 57.71% (with 20% salt addition, w/w) without the need for pre-concentration of the waste. Despite relatively low lithium recoveries, water leaching of activated powder produced remarkably low concentrations of co-leached ionic impurities less than 10 ppm Mg, 20 ppm Ca, and 250 ppm K, compared to significantly higher concentrations observed during 1 M acid leaching (9422 ppm Mg, 564.5 Ca, and 72.5 ppm K, upon 1 M acid leaching, respectively). The presence of Mg ions, in particular, is known to be highly detrimental competing ion in metal recovery processes. Therefore, the proposed method offers both economic and environmental advantages by enabling higher purity lithium recovery under much milder conditions.