Fluxing Calcareous Stone for Steel Mills from China
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 — China → United States
35%
Rate breakdown
9903.03.0110%Except for products described in headings 9903.03.02–9903.03.11, articles the product of any country, as provided for in subdivision (aa) of U.S. note 2 to this subchapter
9903.88.0325%Except as provided in headings 9903.88.13, 9903.88.18, 9903.88.33, 9903.88.34, 9903.88.35, 9903.88.36, 9903.88.37, 9903.88.38, 9903.88.40, 9903.88.41, 9903.88.43, 9903.88.45, 9903.88.46, 9903.88.48, 9903.88.56, 9903.88.64, 9903.88.66, 9903.88.67, 9903.88.68, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(e) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(f)
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