Calcined Sodium Borate Flux Grade
This calcined concentrate of natural sodium borates is processed for use as a flux in glassmaking and enameling industries. HTS 2528.00.0005 covers it explicitly as calcined natural sodium borates from mineral sources, not brine. It lowers melting points in high-temperature applications.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If further refined post-calcination
Any additional chemical processing moves it from natural minerals to synthetic borates in Chapter 28.
If incorporated into refractory bricks
Borates bound in finished refractory products classify under Chapter 69 as worked articles.
If blended with vermiculite/perlite
Mixtures with other Chapter 25 minerals may fall under heading 2530 for mineral substances.
Not sure which classification is right?
Our AI classifier can analyze your specific product and recommend the correct HTS code with confidence.
Import Tips & Compliance
• Include calcination temperature logs in documentation; test for heavy metal contaminants per import standards
• Use heat-sealed packaging to prevent moisture reabsorption
Related Products under HTS 2528.00.00.05
Calcined Ulexite Ore Concentrate
Ulexite is a natural sodium calcium borate mineral concentrated and calcined for industrial use in glass and ceramics production. It falls under HTS 2528.00.0005 as a natural sodium borate concentrate that has been calcined, excluding borates separated from brine. This form enhances solubility for manufacturing applications.
Kernite Sodium Borate Concentrate
Kernite is a naturally occurring sodium borate mineral (Na2B4O7·4H2O) mined and concentrated for use in detergents and agriculture. Classified under HTS 2528.00.0005 as a natural sodium borate concentrate, not derived from brine separation. It provides a key source of boric oxide for various industries.
Uncalcined Borax Ore (Tincal)
Tincal, or natural crude borax, is a sodium borate mineral concentrate extracted from evaporated lake deposits and used in metallurgy. It qualifies for HTS 2528.00.0005 as an uncalcined natural sodium borate concentrate from non-brine sources. This form is valued for its fluxing properties in welding.
Natural Sodium Borate Powder (Concentrate)
Fine-ground concentrate from natural sodium borate ores, suitable for ceramic glazes and herbicides. Classified in HTS 2528.00.0005 for natural sodium borates whether calcined or not, provided not from separated brine. Particle size controlled for uniform dispersion in formulations.
Ulexite Sodium Borate Lumps
Lump-form concentrate of ulexite, a fibrous sodium borate mineral used in fiberglass production. Falls under HTS 2528.00.0005 as natural sodium borate not separated from brine, in minimally processed lump state. Ideal for controlled dissolution in manufacturing.
Calcined Tincal Borate Concentrate
Heat-treated tincal (natural borax) concentrate for soldering fluxes and heat-resistant alloys. HTS 2528.00.0005 includes calcined forms of natural sodium borates from solid mineral deposits. Provides essential boron for metallurgical processes.