Phosphogypsum Processing for Rare Earths Recovery—A Review

As a by-product from the phosphate fertilizer industry Phosphogypsum (PG) was considered a potentially valuable source of the rare earth elements (REEs). Because of trace concentration of REEs in the PG (normally 2SO4, HCl and HNO3, and organic chemicals, the effects of mechanical treatment of PG by microwaving and grinding on leaching efficiency of REEs, and resin-in-leach process were reviewed in the paper.