Calcined Kyanite Powder
Calcined kyanite is a high-alumina aluminosilicate mineral processed by heating to stabilize its crystal structure, preventing volume expansion during ceramic firing. It is classified under HTS 2508.50.00.00 as calcined kyanite, a form of sillimanite group mineral used primarily in refractory and ceramic applications.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If uncalcined and in natural state
Unc alcined kyanite remains classified as kyanite in natural, unworked form under siliceous fossil meals heading.
If chemically synthesized rather than naturally derived
Synthetic mullite from chemical processes falls under chemical preparations, not natural mineral products.
If chemically modified with binders for industrial compounds
Processed into chemical preparations or reaction products moves from Chapter 25 minerals to Chapter 38.
Not sure which classification is right?
The Tariff Assistant works through the GRI rules on your specific product to reach the right HTS code — and can price the duty on it in the same conversation.
Import Tips & Compliance
• Verify mineral purity through lab analysis certificates to confirm andalusite/kyanite/sillimanite content over 50% as per Chapter 25 notes
• Include heat treatment records showing calcination process to distinguish from unprocessed minerals under heading 2512
• Avoid misclassification as synthetic mullite (HTS 2529); provide geological origin documentation
Related Products under HTS 2508.50.00.00
Raw Andalusite Ore
Raw andalusite ore consists of natural andalusite crystals extracted from deposits, typically containing 55-60% alumina. Classified under HTS 2508.50.00.00 as uncalcined andalusite, it serves as a raw material for refractory bricks and high-temperature ceramics.
Sillimanite Grain for Refractories
Sillimanite grains are crushed and sized particles of sillimanite mineral (Al2SiO5) used in refractory castables and ramming mixes. This product falls under HTS 2508.50.00.00 as unprocessed sillimanite, valued for its high melting point above 1600°C.
Calcined Andalusite 55% Al2O3
Calcined andalusite with 55% alumina content is heat-treated to convert partially to mullite, improving thermal shock resistance. HTS 2508.50.00.00 covers this calcined form before further processing into finished refractories.
Kyanite Flour -325 Mesh
Ultra-fine kyanite flour (-325 mesh, <44 microns) used as filler in porcelain insulators and spark plugs. Classified under HTS 2508.50.00.00 as ground kyanite, not chemically modified.
South African Andalusite Lumps
Andalusite lumps from South African Namaqualand deposits, sized 10-100mm, containing 58% Al2O3. HTS 2508.50.00.00 applies to this natural uncalcined mineral export product used globally in steel ladle refractories.
Mullite-Forming Kyanite Concentrate
Beneficiated kyanite concentrate selected for optimal mullite formation during firing, 99%+ purity. Falls under HTS 2508.50.00.00 as processed but uncalcined kyanite per Chapter 25 definitions.