Calcined Colemanite Borate Ore from Mexico
Colemanite is a naturally occurring calcium borate mineral mined primarily in Turkey, calcined to remove moisture while preserving its borate content. It falls under HTS 2528.00.00 as a natural borate concentrate, not separated from brine, used mainly in glass and ceramic production. The calcination process is explicitly allowed without changing its classification.
Duty Rate — Mexico → United States
10%
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
Import Tips
• Verify borate content via assay certificates to confirm <85% H3BO3 for natural boric acid variants and ensure no brine separation
• Obtain mining origin documentation as many suppliers are from Turkey; check for calcination process records to avoid misclassification