Smelted from phosphate rock and iron ore in an electric furnace, grade FeP24 to YB/T 5036: P 23.0–25.0%, Si ≤3.0%, C ≤1.0%, S ≤0.5%, Mn ≤2.0%, with FeP21 (P 20.0–23.0%) and FeP18 (P 17.0–20.0%) also available. The workhorse phosphorus additive for metallurgy — raising phosphorus in steel to improve machinability and atmospheric corrosion resistance in free-cutting and weathering steels, and used in wear-resistant phosphatic cast iron for rolls, cylinder liners and construction-machinery parts where a network phosphide eutectic lifts hardness and abrasion resistance. Also applied in powder metallurgy, welding consumables and phosphating chemicals. Supplied as natural lumps, 5–50 mm, 1–10 mm, 0–1 mm, with 10–100 mm on request; packed in 1-tonne bulk bags with plastic liners or 25 kg laminated woven bags.
