HS Code for Sillimanite

Sillimanite is classified under HS code 2508.50, a specific subheading within Chapter 25 which covers salt, sulfur, earths, and stone, as well as plastering materials, lime, and cement. This classification is determined by the mineralogical nature of the product. Sillimanite is an aluminum silicate polymorph (Al2SiO5) that is primarily used in the production of high-alumina refractory materials due to its ability to withstand extreme temperatures and thermal shock. According to the General Rules of Interpretation (GRI) and the Chapter Notes for Chapter 25, minerals in this category are generally in their crude state or have undergone basic processing such as washing, crushing, or grinding. HS code 2508.50 specifically groups sillimanite with its polymorphs, andalusite and kyanite, because they share nearly identical chemical compositions and industrial applications. Even when sillimanite is calcined (heated to high temperatures to remove impurities or change physical properties), it remains within this heading, provided it has not been further worked into a finished refractory shape, which would move it to Chapter 68.

Products Included

• Raw sillimanite ore
• Calcined sillimanite
• Sillimanite sand
• Ground or crushed sillimanite
• Sillimanite concentrates

Common Misclassification

Sillimanite is frequently misclassified under HS code 2508.30, which is reserved for fire-clay. While both are used in refractories, sillimanite is a distinct mineral species. Another common error is using HS code 2606.00 for aluminum ores and concentrates; however, sillimanite is not considered a primary ore for the extraction of aluminum metal, but rather an industrial mineral. Additionally, if sillimanite has been manufactured into bricks or pipes, it must be classified under 6806 or 6902 rather than 2508.50.

FAQ

What is the HS code for sillimanite?

The HS code for sillimanite, whether in its natural state or calcined, is 2508.50.

Is calcined sillimanite classified differently than raw sillimanite?

No, both raw and calcined sillimanite are classified under HS code 2508.50, as Chapter 25 allows for heat treatment to remove volatile components or for sintering.