Study on synergistic leaching of potassium and phosphorus from potassium feldspar and solid waste phosphogypsum via coupling reactions

• A novel coupled synergistic process using phosphogypsum (PG) and potassium feldspar (PF) achieves simultaneous leaching of potassium (K) and phosphorus (P) with high efficiencies: >93% for K and >96% for P under optimal conditions. • The process leverages the fluorine (F) in PG to generate hydrofluoric acid (HF) in situ, which decomposes the stable structure of PF, enabling K extraction without the need for expensive and hazardous external HF. • Kinetic analysis using the shrinking core model reveals two distinct stages controlled by internal diffusion, with low apparent activation energies (11.92 and 11.55 kJ·mol⁻¹), indicating a thermodynamically favorable and energy-efficient process. • This approach addresses the dual environmental challenges of PG stockpiling and PF underutilization, aligning with circular economy principles and offering a sustainable pathway for waste valorization and resource recovery.