Leaching of Critical Rare-Earth Elements from Industrial Phosphogypsum from the Wizo´w Deposit

Phosphogypsum (PG) is a by-product of phosphate fertilizer production, consisting mainly of calcium sulfate dihydrate that retains toxic trace elements and radionuclides, leading to environmental contamination concerns due to the 200 million tons of PG produced annually. This study focuses on the hydrometallurgical recovery of critical rare-earth elements (REEs) from PG sourced from a former chemical plant in Wizo´w, Poland. Leaching experiments were conducted using various solvents to assess REE extraction efficiency, with elemental analysis performed via inductively coupled plasma–mass spectrometry (ICP-MS). Total REE concentrations (RREEs) were found to range from 0.04 to 1.57% w/w, demonstrating the potential of PG waste as a secondary resource for REE recovery. The findings support sustainable hydrometallurgical processing of PG, which offers environmental benefits by reducing waste and contributes to raw material security in the European Union (EU) context, where REEs are listed as critical raw materials due to their economic significance and growing demand in high-performance technologies.