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[Display omitted] • Synergistic quaternization/phosphonation of algal/PEI beads favors W(VI) binding. • Langmuir dual site and Sips models for fitting isotherm for bi-functional sorbent. • Fast kinetics (≈60–90 min) fitted by pseudo-second order rate equation. • High stability in sorption and desorption performance (at 5th recycling). • Selectivity for W against base and alkali-earth metals (in real effluent). Algal/polyethyleneimine composite beads (A L PEI) have been successfully functionalized by grafting phosphonate (A L PEI-P), quaternary ammonium groups (A L PEI-Q), and by dual moieties (A L PEI-PQ). The materials are characterized by a wide diversity of analytical methods: SEM and SEM-EDX, TGA, BET, FTIR and XPS, elemental analysis and titration (detailed discussion in Supplementary Information). FTIR and XPS analyses show contributions of quaternary ammonium, hydroxyl, and phosphonate groups in tungstate binding (which may involve polynuclear species, depending on the pH). The synergistic effects of phosphonate and quaternary ammonium moieties contribute to strongly increase W(VI) sorption capacity up to 1.8 mmol W g−1 (i.e., 4-times compared with pristine beads), at pH 5. The strong increase of sorption properties with temperature (2.45 mmol W g−1 at T: 50 °C) demonstrates the endothermic nature of metal binding, which is spontaneous (and characterized by positive entropy change). The Langmuir Dual Site equation successfully fits sorption isotherm for functionalized sorbents (bearing phosphonate and phosphonate/quaternary ammonium groups in addition to proper reactive groups of pristine beads) contrary to the isotherms for raw beads (fitted by Langmuir equation). The pseudo-first order rate equation fits kinetics (equilibrium reached within ≈60 min). The bi-functional sorbent shows marked preference for W(VI) against base and alkali-earth metals (especially at pH close to 3.5). These properties are confirmed in the treatment of raffinate solutions (after ore leaching and solvent extraction): despite the complexity of the effluent, A L PEI-PQ reveals highly efficient for W(VI) recovery and separation. The sorbent can be used as a polishing treatment for enhancing the recovery of strategic metals. Sorbed tungstate is readily desorbed from the sorbent using 0.2 M NH 4 Cl solution. The sorbent is efficiently recycled for at least 5 cycles (complete desorption, loss in sorption performance less than 4% at the fifth cycle). [ABSTRACT FROM AUTHOR]

[Display omitted] • Reuse of lithium phosphate slag to prepare high-purity FePO 4 and Li 2 CO 3 was achieved. • The Al3+ ion was effectively removed by solvent extraction with minimal loss of Li+ and PO 4 3−. • The synthesized FePO 4 and Li 2 CO 3 exhibited excellent physicochemical performance. • The findings provide novel insights for the clean recovery in the lithium phosphate slag field. The efficient utilization of lithium and phosphate resources from lithium phosphate slag, a byproduct originated from lithium extraction, holds great significance for environmental protection and industrial advancement. Existing methods primarily focus on Li extraction from this slag, while phosphate resources are often overlooked. In this work, we proposed an alternative approach based on impurity extraction, followed by sequential precipitation of FePO 4 and Li 2 CO 3 , to concurrently recover lithium and phosphate from lithium phosphate slag. The results demonstrated an aluminum separation efficiency of 85 %, effectively reducing the aluminum concentration in the raffinate to below 25.0 mg/L. The extraction reaction, facilitated by saponification, involved cation exchange between Al3+ and Na+. The synthesis process of FePO 4 ·2H 2 O was predominantly controlled by the chemical reaction with an activation energy of 102.8 kJ/mol. The obtained FePO 4 ·2H 2 O and Li 2 CO 3 products met the standards for battery-grade materials. Notably, the process achieved a remarkable phosphorus recovery rate of 98.7 % while maintaining a low lithium loss rate of below 2.0 %. This work presents an efficient and environmentally friendly method for achieving comprehensive recovery of lithium and phosphate resources from lithium phosphate slag. [ABSTRACT FROM AUTHOR]