Template-free synthesis of P zeolite from clay-type lithium ore with high Si/Al utilization efficiency for copper removal

Eliminating harmful Cu 2+ from tainted water is still a major environmental problem. In this study, we achieved efficient removal of Cu 2+ from the solution by Na Li co-doped P zeolite (NLPZ), which was synthesized by template-free method. This method fully utilizes the Si/Al ratio in clay-type lithium ore, achieving high utilization rates of Si (94.72 %) and Al (96.62 %). Simultaneously, benefiting from the synergistic contribution of the synthesis stage and subsequent ion exchange, the overall lithium retention rate reaches as high as 82.60 %. The NLPZ exhibited exceptional Cu 2+ adsorption capacity (139.31 mg/g at 25 °C) through a dual mechanism: (1) ion exchange and (2) hydroxyl-mediated surface complexation. Adsorption followed pseudo-second-order kinetics and the Langmuir isotherm consistent with monolayer chemisorption, while thermodynamic analysis revealed endothermic behavior (ΔH = 5.9108 kJ/mol). In addition, the NLPZ maintained 94 % adsorption capacity after five regeneration cycles, demonstrating superior stability. This work provides an eco-friendly and scalable strategy for treating copper-contaminated wastewater by synergizing the efficient extraction of Si/Al from ore with the template-free synthesis of P-type zeolites.