Calcined Mullite Aggregate from Mexico
Calcined mullite aggregate consists of crushed and heat-treated mullite grains used as a raw material in high-temperature refractories and castables. Classified under HTS 2508.60.00.00 as calcined mullite among other refractory earths.
Duty Rate — Mexico → United States
10%
Rate breakdown
9903.05.5510%Section 301 (forced labor) — additional 10% ad valorem on products of Mexico
Import Tips
• Provide heat treatment records proving calcination without shaping to maintain classification as earth rather than articles
• Label packages with grain size distribution (e.g
• 3-6mm) and mullite content percentage for customs verification
• Avoid common error of importing pre-mixed castables, which may classify under 3816 as refractory cements