Non-agglomerated concentrates (260111) include iron ore fines, crushed ore, and pellet feed that have not been bound into a formed shape. Agglomerated concentrates (260112) have been processed — by sintering, pelletizing, or briquetting — into a physically cohesive form suitable for direct charging into a blast furnace. The processing method and physical form of the material at the time of importation determine which subheading applies.

Roasted iron pyrites (260120) are the calcined residue of iron sulfide (pyrite) after sulfur has been driven off, typically as a byproduct of sulfuric acid production. They differ from iron ore concentrates in their origin and sulfur history. While both contain iron oxide, pyrite cinders are classified separately because of their distinct production process and typically lower iron grade compared to purpose-mined iron ore concentrates.