2518.20.00.00 - Calcined or sintered dolomite

This HTS category, 2518.20.00.00, specifically covers dolomite that has undergone a calcination or sintering process. Calcination involves heating dolomite to high temperatures, driving off carbon dioxide and transforming it into calcium magnesium oxide (magnesite). Sintering achieves a similar result by fusing the dolomite particles together without fully melting them. These processes fundamentally alter the chemical and physical properties of the raw dolomite, typically increasing its refractory properties and reducing its reactivity.

This classification distinguishes itself from its sibling category, 2518.10.00.00, which pertains to dolomite in its natural, uncalcined, and unsintered state. While both categories deal with dolomite, the key differentiator lies in the thermal treatment. Goods classified under 2518.20.00.00 will exhibit characteristics resulting from these high-temperature processes, such as increased hardness, altered porosity, and specific chemical compositions suitable for applications requiring heat resistance.

As this is a leaf node in the HTS structure, there are no further subdivisions under 2518.20.00.00. Therefore, classification within this category depends entirely on whether the dolomite has been subjected to calcination or sintering. Examples of goods falling under this classification would include dead-burned dolomite used in refractory linings for furnaces and kilns, or other forms of processed dolomite intended for specialized industrial applications where the raw material would be unsuitable.