2507.00.00.00 - Kaolin and other kaolinic clays, whether or not calcined

This HTS category, 2507.00.00.00, specifically classifies kaolin and other kaolinic clays. These are naturally occurring aluminosilicate minerals, often referred to as "china clay," primarily composed of the mineral kaolinite. The classification encompasses both calcined and uncalcined forms of these clays. Calcined kaolin undergoes heating to remove chemically bound water, altering its properties for industrial use, while uncalcined kaolin retains its natural hydrated state.

The distinction from sibling categories at the same level (Chapter 25) is crucial. While Chapter 25 broadly covers earths and stones, this specific heading isolates kaolin and kaolinic clays. It excludes other clays like bentonite (heading 2508.10) or other earths such as fuller's earth (heading 2508.90), which have distinct chemical compositions and industrial applications. It also differentiates from non-clay mineral substances covered elsewhere in Chapter 25, focusing solely on this particular group of clay minerals.

As this is a leaf node, there are no further subcategories within 2507.00.00.00. Classification relies on the precise identification of the material as kaolin or a kaolinic clay, irrespective of whether it has been processed by calcination. Typical applications for goods classified here include their use in the manufacturing of ceramics, paper, paints, rubber, plastics, and as refractory materials. The presence of kaolinite as the predominant mineral constituent is the primary determining factor for classification under this heading.