Fluxing Calcareous Stone for Steel Mills from Canada
Coarse angular calcareous stone flux, sized 1-4 inches, used in steel mill basic oxygen furnaces to form slag and protect furnace linings. HTS 2521.00.00.00 covers this as limestone flux specifically for lime-related industrial processes. Its high melting point and impurity-binding properties define its metallurgical role.
Duty Rate — Canada → United States
10%
Rate breakdown
9903.05.2910%Except for products described in headings 9903.05.85–9903.05.93, articles the product of Canada, as provided for in U.S. note 52 to this subchapter
Import Tips
• Include steel mill purchase orders referencing flux specifications to substantiate end-use for classification
• Conduct sieve analysis to document flux sizing, preventing confusion with general crushed rock
• Beware of blending with dolomite; mixtures may require separate classification under 2518