Phosphogypsum

Appearance: loose powdery material, light gray to beige in color
Calcium sulfate content (CaSO₄·2H₂O), %: 85–95
Moisture content, %, max: 10
pH (10% solution): 5.0–6.5
Impurities: may contain trace amounts of phosphorus, fluorine, and organic residues
PARTICLE SIZE DISTRIBUTION
Mass fraction of particles smaller than 0.5 mm, %, not less than: 90
Friability, %: 100